-
c Cardiology and Cardiovascular Surgery Mark Dam, Shiying Liu
and Michael Ward. chapter editors Doreen Ezeife and Nigel Tan,
associate editors Stnen Wong, EBM editor Dr. Chi-Ming Chow, Dr.
Andrew Dueck and Dr. Anna Woo, staff editors With contributions
from Dr. Young Kim
Basic Anatomy Review .. 2 Coronary Circulation Cardiac
Anatomy
Differential Diagnoses of Common Presentations . . . . . . . . .
. . . . . . . . . . . . . . . . . . 4 Chest Pain Syncope Local
Edema Generalized Edema Palpitations Dyspnea
Cardiac Diagnostic Tests .................. 5
Electrocardiography (ECG) Basics Approach to ECGs
Rate Rhythm Axis Intraventricular Conduction Abnormalities
Hypertrophy and Chamber Enlargement Ischemia/! nfarction
Miscellaneous ECG Changes
Other Cardiac Diagnostic Tests Cardiac Biomarkers Ambulatory ECG
Echocardiography Stress Testing
Nuclear Cardiology Cardiac Catheterization and Angiography
Contrast-Enhanced CT Coronary Angiography Magnetic Resonance
Imaging (MRI)
CARDIAC DISEASE Arrhythmias ........................... 12
Mechanisms of Arrhythmias Bradyarrhythmias AV Conduction Blocks
Supraventricular Tachyarrhythmias Pre-Excitation Syndromes
Ventricular Tachyarrhythmias Electrophysiology (EPS) Studies
Electrical Pacing Implantable Cardioverter Defibrillators (ICDs)
Catheter Ablation
Ischemic Heart Disease (IHD) ............. 22 Chronic Stable
Angina Acute Coronary Syndromes (ACS)
Unstable Angina (UA)/Non-ST Elevation Ml (NSTEMI) ST-Eievation
Myocardial Infarction (STEMI)
Treatment Algorithm for Chest Pain Sudden Cardiac Death Coronary
Revascularization
Percutaneous Coronary Intervention (PCI) Coronary Artery Bypass
Graft (CABG) Surgery Off Pump Coronary Artery Bypass (OPCAB)
Surgery
Toronto Notes 2011
Heart Failure. . . 32 Congestive Heart Failure (CHF)
Sleep-Disordered Breathing
Cardiac Transplantation ................. 35 Ventricular Assist
Devices (VADs)
Myocardial Disease ..................... 36 Myocarditis Dilated
Cardiomyopathy (DCM) Hypertrophic Cardiomyopathy (HCM) Restrictive
Cardiomyopathy (RCM)
Valvular Heart Disease .................. 40 Infective
Endocarditis (IE) Rheumatic Fever Choice of Valve Prosthesis
Summary of Valvular Disease
Pericardia! Disease ...................... 44 Acute Pericarditis
Pericardia! Effusion Cardiac Tamponade Constrictive
Pericarditis
VASCULAR DISEASE Peripheral Arterial Disease ............... 46
Acute Arterial Occlusion/Insufficiency Chronic Arterial
Occlusion/Insufficiency
Hypertension .. FM35
Pulmonary Hypertension ............... R16
Carotid Artery Disease ................ NS21
Aortic Disease ......................... 48 Aortic Dissection
Aortic Aneurysm
Peripheral Venous Disease .. 51 Deep Venous Thromboembolism
Superficial Thrombophlebitis Varicose Veins Chronic Venous
Insufficiency Lymphedema
Common Medications ................... 54
Landmark Cardiac Trials ................. 57
References . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 59
Cardiology and CV Surgery Cl
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C2 Cardiology and CV Surgery 1'oroDio 2011
Basic Anatomy Review Coronary Circulation
Dillltol8
conventional arterial supply to the heart arises from the right
and left coronary arteries, originating from the root of the aorta
(see Figure I)
right coronary artery (RCA) acute marginal branches
atrioventricular (A V) nodal artery posterior Interventricular
artery (PIV) = posterior descending artery (PD)
Left main coronary artery (LCA): two major branches left
anterior descending artery (LAD)
- septal branches - diagonal branches
left drcumfleJ: artery (I.Cx) - obtuse marginal branches
dominance of drculatlon right-dominant circulation: PIV and at
least one posterolateral branch arise from RCA (8096) Left-dominant
circulation: PIV and at least one posterolateral branch arise from
LCx (1596) balanced cin::ulation: dual supply ofposteroinferior LV
from RCA and LCx (596)
the sinoatrial (SA) node ia supplied by the SA nodal artery,
which may arise from the RCA (60%) or LCA (40%)
most venous blood from the heart drains into the RA through the
coronary a:lnns, although a small amount drains through Th.ebesian
veins into all four chambers, contributing to the physiologic R-L
shunt
Laft IDDI' dncending (LAD)
Aare 1. Anatomy of tile Coronary Arterl11 (llgld: alterlor
oblque pro)ecGon)
I SVI!ol8 I
l '- --% .... ' \ .... 10 I 'u ., lA ('"LV- .,_- !Ill "'-
MV-
D \ I. ,.,..
Legend: AV-IICirticiiM LA -kilt lllrn LV -left'llllllricle I
I
Carotid Pul"
JVPWIWform Cardiae
so 40 R . _. =,_
llaat l > Soundl .
Q a 'A 0.8 lime(secl
Flg1re Za. Cardiac Cycle
PIN- milrlll valva
c Anll .... 211011
s, s,
QRS AblaJt I-Alii II A brillion Camoll-3ft! dep l'elltblodt
tv_..: Tra.pd eii.Mbd JVP Card II: r....-: xdlant anly, llbsarty
dMclnt
ECG
l'rl!rrirrtyd8Qrt. runn.urs 1191
Flgere 2b. Canllac Cycle. JVP Pulle and Cai'GIId Pllsa
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'IbroDlo Nota 2011 Buic Anatomy Review
Cardiac Anatomy layen of the heart
endocardium myocardium epicardium =visceral pericardium
pericardia! space parietal pericardium
"Y&lves tricuspid valve (TV): separate.. RA and RY pubrulDic
valve (PV): separates RY and pulmonary artery (PA) mitral valve
(MV): separates LA and LV aortic valve (AV): separates LV and
ucending aorta
oonchu:tion aydem impulses travel from: SA AV bundle: of His
LBB/RBB -+ Purkinje fibres SA node governs pacemaking control
anterior-, middle- and posterior-internal nodal tracts carry
impulses in the right atrium and
along Ba.chmann's bundle In the left atrium atrial impulses
converge at the AV node
the AV node is the only conducting tract from the atria to the
ventricles because of electrical isolation by the annulus fibrosis
(except when accessory pathways are present)
the bundle of His bifurcates into left and right bundle
bl'llllCbes (LBB and RBB) LBB further splits into anterior and
posterior fascicles RBB and fasdclt:s ofLBB give o1fPurkinje fibres
which conduct impulses into the ventricular
myocardium canllovascular lnncmdio.n
lfiiiP8thet:lc nerves innervate the sinoatrial node (SAN),
atroventricular node (AVN), ventricular
myocardium and vasculature SAN (pl) fibres increase pacemaking
activity (chronotropy) cardiac muscle fibres increase contractllity
(inotropy) to help increase cardiac output stimulation of IH- and
IJ2-receptora in the W:1.etal and coronary c.ln:ulation causes
vasodllatation parasympathetic nenes
Innervate the SAN, AVN, atrial myocardium but few vascular beds
basal vagal tone dominates the tonic sympathetic stimulation of the
SAN and AVN
resulting in slowing of pacemaking activity and condw:tion (ie.
reduced chronotropy and drmnotropy)
parasympathetic& have very little impact on total peripheral
vascular resistance
- Middle 1rlct
- Posteriorlrlle:t
Figun 3. Conduction Systam of the Heart
lknlla aiHII
Cl Ytulg M. IGm 2010
Cardiology and CV SUJ'8ery C3
-
C4 Cardiology and CV Surgery Differential Diagnose5 of Common
Presentations Toronto Notes 2011
Differential Diagnoses of Common Presentations Note: bold text
indicates most common, underlined text indicates life
threatening
Chest Pain Pulmonary
pneumonia pulmonary embolism (PEl pneumothorax/hemothorax,
tension pneumothorax empyema pulmonary neoplasm bronchiectasis
TB
Cardiac Ml/angina myocarditis pericarditis/Dressier's syndrome
cardiac tamJonade
Gastrointestin esophageal: spasm, GERD, esophagitis,
ulceration,
achalasia, neoplasm, Mallory-Weiss syndrome PUD gastritis
pancreatitis biliary colic
Mediastinal lymphoma thymoma
Vascular dissecting aortic aneurysm
Surface structures costochondritis rib fracture skin (bruising,
shingles) breast
Syncope Hypovolemia Cardiac
structural or obstructive causes myocardial disease (e.g. acute
coronary syndrome) aortic stenosis hypertrophic cardiomyopathy
(HCM) cardiac tamponade/constrictivt: pericarditis
arrhythmias (sc:c: arrhythmia section) Respiratory
massiyePE pulmonary hypertension hypoxia hypercapnia
Neuio1ogic stroke/TIA (esp. vt:rtebrobasilar insufficiency)
migraine seizure vuovagal
Metabolic anemia hypoglycemia
Drugs antihypertensives antiarrhythmics beta-blockers, CCBs
Psychiatric panic attack
Local Edema Inflammation/infection Venous or lymphatic
obstruction
thrombophlebitis/deep vein thrombosis chronic lymphangitis
venous insufficiency filariasis
Generalized Edema Increased hydrostatic pressure
increased fluid retention cardiac causes e.g. CHF hepatic causes
e.g. cirrhosis renal causes e.g. acute and chronic renal
failure
vasodilators (especiallyCCBs) refeeding edema
Decreased oncotic pressure hypoalbuminemia
Hormonal hypothyroidism exogenous steroids pregnancy
estrogens
Palpitations Cardiac
arrhythmias (PAC, PVC, SVT, VT) mitral valve prolapse valvular
heart disease J:m>ertrophic obstructive cardiomyqpatby
Endocrine thyrotoxicosis pheochromocytoma hypoglycemia
Systemic fever anemia
Drugs tobacco, caffeine, alcohol, epinephrine, ephedrine,
aminophylline, atropine Psychiatric
panic attack
Dyspnea Cardiovascular
acuteMI CHF/LV failure aortic stenosis/mitral stenosis cardiac
elevated p onary venous pressure
Respiratory airway disease
asthma COPD exacerbation upper airway obstruction (anaphylaxis,
foreign body,
mucus plugging) parenchymal lung disease
ARDS pneumonia interstitial lung disease
pulmonary vascular disease pulmonary embolism pulmonary HTN
pulmonary vasculitis
pleural disease pneumothorax
pleural effusion Neuromuscular and chest wall disorders
C-spine injury polymyositis, myasthenia gravis, Guillain-Barre
syndrome kyphoscoliosis
Anxiety/psychosomatic Severeanemia
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'IbroDlo Nota 2011 Cardiac Diagnostic Testl
Cardiac Diagnostic Tests Electrocardiography (ECG) Basics
the electrocardiogram (ECG) is a graphic representation of the
electrical activity of the heart recorded from the surface of the
body
on the ECG graph the horizontal axis represents time
1 mm. (I small square)= 40 msec 5 mm. (I large square) = 200
.l1lllec (at paper speed 25 mmlaec)
the vertical axis represents voltage 1 mm. (I small square) =
0.1 m V 10 mm. (2large squares)= 1 mV (at standard gain
setting)
leads standard 12-leadECG
Umb leads: I. II, DI. a VI., aVR. aVF precordial leads: VI-V6
(VI-V2 septal, V3-V 4 anteriol; VS-V6lateral)
additional leads right-sided leads: V3R-V6R (useful in RV
infarction and dmrocardia)
lateral = I, a VL, V5, V6; inferior = II, Til, a VF; &ontal
= VI-V 4
Approach to ECGs Rate normal = 60-100 bpm (atrial mre: IS0-250
bpm = paroxsyma1 tachycardia, 250-350 bpm = atrial
flutter, >350 bpm = atrial fibrillation regular rhythm
to calculate the rate, divide 300 by number of large squares
between 2 QRS complexes (there are 300 large squares in 1 minute:
300 x 200 maec = 60 sec)
or remember 300-150-100-75-60-5()....43 (rate falls in this
sequence with the number of additional large squares between
QRS)
irregu1a.r rhythm rate = 6 x number ofR-R intervals in 10
seconds (the '"rhythm strips" are 10 second
recordings) types: wandering pacemaker, multifocal atrial
tachycardia. atrial fibrillation
atrial escape = 60-80 bpm; Junctional escape = 40-60 bpm;
ventricular escape = 20-40 bpm Rhythm regular = R-R interval is the
same aaoss the tracing irregular= R-R interval va.rl.es across the
tradng
regularly-irregula.r = repeating pattern of varying R-R
intervals irregularly irregular = R-R intervals vary
erratically
normal sinus rl:rythm (NSR) P wave precedes each QRS; QRS
follows each P wave P wave axis is normal (positive in leads I, a
VF) rate between 60-100 bpm
Axis mean axis indicates the direction of the mean vector can be
determined for any waveform (P, QRS, T) the standard ECG reported
QRS axis usually refers to the mean axis of the frontal plane;
it
indicates the mean direction of ventricular depolarization
forces QRS axis in the horizontal plane is not routinely
calculated; it Is directed posteriorly and to the
left the transition from negative to poaltive is usually In lead
V3
QRS axis in the frontal plane (see Flgure 5) normal uis: -300 to
90" (i.e. posltive QRS in leads I and II) left axis deviation
(LAD): axis 90
Cardiology and CV SUJ'8ery C5
O..nrillw flf DiatiDSiic r .... Cmilc IHrurllllra (T n. CK-MB)-
in
-vmptullllllie IIBbl ECG-atrwt. wi11ulnl-. orin
-vmptullllllie IIBbl 811811. or with .... IIM:t.r illqi .. -
wi1h lb8la tmilc clllleterizltiant CTA MIIAIM!I
Figura 4. ECG WHeferma 11d Nannll Values
111118 Cllculltianl Examples Practice
....
AJtnuh ta EC&I &IIIIIIIY Rail Rhythn Axis Conducti111
Clwmbar rRIII!IIII&ntfhypatrophy lschami.-'lnhuctian
Milcelllneoua
Far mara 111d 'iisit
L8ft Ant. Hemiblack lnlllriorMI WPW RV Pacing N0111111IYariant
BIMdlld llillplngm Llad Mispl-mant Endocardial CUIIian dafacl
RVH l..aftl'oat Hamibhx:k PE COPD t..1anll Ml WF'W
Dllldracanlill Sapbll Dahn:1a
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C6 Cardiology and CV Surgery
Figure 5. Axial Reference System Elldlilld conlliis I+) Bill
dispid by 1hi!DI llmiWI. lirpJEstllllei"-J toward the plllitM
ol1flllllll rlllllts in Ill upMtd dallection il thatilld. NonriiQRS
IIliis is between -30'111d +90'.
Cardiac Diagnostic Teats Toronto Notes 2011
Intraventricular Conduction Abnormalities
Right Bu1dla BI'IIICh Block (RBBBJ Lift Bundl1 B111nch Block
(LBBBJ CampiBIB RBBB Ca11platll LIBB QRS duration > 120 msec QRS
dLnlion > 1 20 msec Positive ORS in lead V1 (rSR' or
occasionally broad R wave] Broad S waves in leads I, VS-6 ( >40
msecl
Broad notched or slurred R waves in leads I, aVI.. and usually
V5andV6
Usually secondll'fTWIIW inversion i'lleads V1-2 Deep broad S
waves in leads V1-2 Secondlry ST-T changes (-vein leads with broad
R WIIWS,
+vein V121 are usually present LBBB usually masks ECG signs Df
myocardial inlan:tion
Left Anllriar Fudc:ullr Bloc:k (LAFBI LBft l'oltlriar
F.c:ic:ullr Bloc:k (LPFBI Biflldc:ullr Bloc:k (Left Antcrill'
Hemibloc:kl {Left Pauiar Hemibloc:kl Left axis deviation (-30" 1D
-911"1
Small q and prominent R in leads I and aVL
Small r and prominent S in leads II. IlL and aVF
Right axis deviation ( 11 II" 1D 1811"1 Small r and prominant S
i1
leads I and aVL Small q and prominent R in
leads 11,111, and aVF
RBBB pattern Small q and prominent R
The first 60 msec (1 .5 small squares] Dlthe ORS shows the
pattern Dl LAFB or LPFB
Bilascicular block refers 1D impaired conduction in two of the
three fascicles, most commonly a RBBB and left anterior hemiblock;
the appearance on an ECG meets the criteria fur bDih types of
blocks
Laft Bundla Right Bundle Lift Ventricular Right Ventricular
lll'lllilt Figura 6. Complete LBBB. RBBB. LVH and RVH (only
samples, please see online examples for the full range of waveforms
and the text for additional characteristics I Nonspecific
Intraventricular Block QRS duration >120 msec absence of
criteria for LBBB or RBBB Hypertrophy and Chamber Enlargement left
ventricular hypertrophy (LVH)
Sin V1 + Rin V5 orV6 >35 mmabove age40, (>40 mmforage
31-40, >45 mmforage 21-30) RinaVL>llmm Rin I+ Sin III >25
mm additional criteria:
LV strain pattern (ST depression and T wave Inversion in leads
I, aVL, V4-V6) left atrial enlargement
right ventricular hypertrophy (RVH) right axis deviation R/S
ratio >I or qRin lead VI RV strain pattern: ST segment
depression and T wave inversion in leads VI-2
left atrial enlargement (LAE) biphasic P wave with the negative
terminal component of the P wave in lead VI ; I20 msec, notched in
lead II ("P mitraleD)
right atrial enlargement (RAE) P wave > 2.5 mm in height in
leads II, III, or a VF ("P pulmonalea)
Laft Atrial Enlargement Right Atrial Enlargement
mmmm Figura '1. LAE, RAE (only samples, please see online
examples and text above for characteristics]
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'IbroDlo Nota 2011 Cardiac Diagnoslic Testl
lschamia/lnfrction look fur the anatomic distribution of the
following ECG abnormalities (see Table 1) iachemia
ST segment depression T wave l.nversion (most commonly in
Vl-V6)
injury tra.nsmura.l (involving the eplcardium) - ST elevation in
the leads fadng the area injured/
infarcted; transient ST elevation may occur in patients with
coronary artery spasm (e.g. Prinzmetal angina) can be slight or
prominent (> 10 mm)
I!Ubendocardial- marked ST depression in the leads facing the
affected area; it may be accompanied by enzyme changes and other
signs of myocardial infarction; may also occur with angina
Figure I. ECG CIJanu wiUJ lm.ctiun
evolving infarction (ST elevation in contiguous leads = acute
MI) typical" sequential changes of evolving myocardial
infarction
lilt hyperacute T waves (tall. symmetric T waves) in the leads
facing the infarcted area, with
or without ST elevation 2nd
ST elevation (injury pattern) in the leads facing the lnfarcted
area usually 1n the first hOUIS post Infarct in acute posterior
infarction. there is ST depression in Vl-V3 {reciprocal to ST
elevation
in the posterior leads, that are not recorded in the standard
12-lead ECG) 3rd
significant Q waves: >40 msec or >113 of the total QRS
(hours to days post-infarct) 4th
inverted T waves (one day to weeks after infarction) this
classical sequence, however. does not always occur, e.g.
Q waves of infarction may appear in the very early stages, with
or without ST cha.ngea non-Q wave iDfarction: there may be only ST
or T changes, despite clinical evidence of
infarction completed infarction
abnormal Q (note that wide Q waves may be found in m and a VL in
normal individuals)
duration >40 msec (>30 msec in aVF for inferior
Infarction) QIQRS voltage ratio is >3396
abnormal R waves (RIS ratio > 1, duration >40 msec) in VI
and more frequently 1n V2 are found in posterior infarction
(usually in association with signs of inferior andJor lateral
infarction)
Tillie 1. Area af lnflln:tion{O wava}/lllchamia (right daminant
aiii'IDmy)
Leltar*rior descending (lAD) Anl!mseplal VI,V2
Circumflex
Anlarior V3, V4 Anlllnllltlnl aVL, V3-t Extensivurariar I, aVL,
Vl-t ...... Right verm:le faltsrill" Ml (lillie. with n. Mil Lltlnl
lsdatad postarior Ml
II,IILaVF V3R, V4R (right sided chest leads) VI, V2 fptrilant: R
WIVII) V5-t VI, V2 fptrilant: R WIVII)
Cardiology and CV SUJ'8ery C7
,,
IIIJ!IIIclllt EC& ClllngM Look for ST It 80
mc from J pam J point - the junction betw8111 th1
QRS eompleot and the ST llllment ST aiiMIIion: lit laut 1 mm
il
2 14acant inb lalds, Dr lit least 1-2 rnm in ldjacllll
precordilllds
ST prweion: diiWI!IIgpilg Dr harimntlll
Q WIIVI; pllh*9icll if CIIISO!:lsmall mwcl or >3B of the
11111111lRS
,, . .----------------, Q ._ Sepllll depollrimli1111 by the 11ft
bundle Seen in leads I, II, Ill, aVL.. VS, Vl5
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C8 Cardiology and CV Surgery
.... , ,
'-Vullaae Dafinilion: IDIIII ORS ha9JI in
PIICordillleldl < ID rrm .. d linb lelldii 7 mmoVL):
progressive changes whereby P waves flatten and disappear, QRS
widens and may show bizarre patterns, axis shifts left or right,
ST sblft wltb. tall T waves hypokalemia (see Figure 10)
ST segment depression, prolonged QT interval., low T wwes,
prominent U waves (U> T) enhances the mxic effects of
digitalis
hypercalcemia: shortened QT interval hypocalcemia: prolonged QT
interval 1-Ji-- .,V\ - .jA, - + -1-L - -L,_ f"IIIIIFI 10. HJPGbli
Hypothermia s1nU8 bradycardia when severe, prolonged QRS and QT
intervals
... !\.-"
atrial fibrillation with slow venlricular response and other
alrlallvenlricular dysrhythmias Osborne J waves (see Figure 11):
"bump-like" waves at the junction of the J point and the
STsegmmt
Pericarditis early- diffuse ST segment elevation PR segment
depression. upright T waves lllter - iscelectric ST segment, flat
or inverted T waves low voltage if chronic coD.St:rictive
pericarditis tachycardia Drug Effects digitalis
therapeutic levels may be associated with Kdigitalis dfea- (see
Figure 12): !IT downtdoping or "scooping'" T wave depression or
inversion QT shortening U waves slowing of ventricular rate in
atrial fibrlllation
toxic levels associated with: arrhythmias: paroxysmal atrial
tachycardia (PAT) with conduction bWcks, severe
bradycardia in atrial fibrillation, accelerated junctional
rhythms, PVCs, ventricular tachyt:ardia (seeArrlJythmiru, C12)
"regularization" of ventricular rate in atrial fibrillation due
to a junctional rhythm and AV dissociation
amiodarone, quinidine, phenotbiaziru:s, bicyclic
antidepressants, antipsychotics, some antihistamiD.es, some
antibiotics: prolonged QT interval, U waves
12. Atrial Fllrillation. IT a .. ga duatD Digitalis ("diaitalis
aHacr)
Pulmonary Disorders cor pulmonale (often secondary to COPD)
low voltage, RAD, poor R wave progression RAE and RVH with
strain multifocal atrial tachycardia (MAT)
massive pulmonary embolism (PE) sinU8 tachycardia and atrial
fi.brlllatlon/atrial flutter are the most common arrhytbmlas RAD,
RVH with strain - most specific sign is SIQ3T3 (Sin I. Q and
inverted T wave in rm
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'IbroDlo Nota 2011 Cardiac Diagnostic Testl
Cardiac Biomarkers provide diagnostic and prognomc infonnati.on
and identify increased risk of mortality in acute
coronary syndromes Tallie 2. CM!Iac Enzyna
lllnllal EIMIIId DDx at Elnlllal Tropanin Tropanil T 1-2
days
1day 3days Myocardial inlllrctian. mytJcarditis. pericllllitis.
ITU!IClllar dysbaphy, Cll'dilc dalirlll:ian. ale.
check troponin I at presentation and 8h later creatine kinase-MB
(CK-.MB, depends on local laboratory protocol)
new CK-MB elevation can be wed to diagnose reinfarction,
troponin cannot other biomarkers of cardiac disease:
AST and LDH also increased in myocardial infarction (low
specificity) BNP and NT -proBNP - secreted by ventricles in
response to increased end-diastolic pressure
and volume DDx: CHF. AF. PE, COPD exacerbation, pulmonary
hypertension
Ambulatory ECG indications fur outpatient management:
palpitations, syncope, antiarrhythmic drug monitoring,
and arrhythmia surveillance in patients with docwnented or
potentially abnormal rhythms. surmllance of non-sustamed
arrhythmias that c::an lead to prophylactic intervention
available technologies Holter monitor
battery operated, continually records up to 3 leads hn symptoms
remrded by patient on Holter clock fur mrrelation with ECG
findings
continuous loop recorder (diagnostic yield 66-8396) worn
continuously and can record data before and after patient
activation fur
symptomatl.c episodes (usually worn fur 2 weeks) external and
implantable devices
external devices can be tran.stelephonically downloaded
implantable loop recorder (ll.R) -implanted subcutaneously to the
right or left of the
sternum; triggered by placing an activator aver it; anterograde
and retrograde recording time is programmable; cannot be
tran8telephonically downloaded; left in place for 14 to
18montlu
Echocardiography Transthoracic Echocardiogrephy (TTE) ultrasound
beams are directed across the chest wall to obtain images of the
heart indications: evaluation ofleft ventricular ejection fraction
(LVEF), wall motion abnormalities,
myocardJal ischemia and compllcations of MI, chamber sizes, wall
thickness, valve mozphology, pranmal great vessels. pericardia!
effusion. unexplained hypotension, murmurs, syncope, congenital
heart disease
use with Doppler, which is used to quantify degree of valvular
stenosis or regurgitation Trensoeaophageal Echocardiography (TEE)
ultrasound probe inserted into the esophagus to allow fur better
resolution of the heart and its
structures better visualization of posterior structures, such as
left atrium, mitral and aortic valves,
interatrialaeptum invasive procedure, used to complement
transthoracic echocardiography indications: intracardiac thrombi,
tumours, valvular vegetations (infective endocarditis),
aortic dissection, aortic atheromas, prosthetic valve function,
shunts, technically inadeqwrte transthoracic studies
use with Doppler, which is used to quantify degree of valvular
stenosis or regurgitation Stress Ec:hocardlography echocardiography
in combination with either physiologic (exercise treadmill or bike
testing) or
pharma.cologic (dobutamine infusion) stress validated in
demonstrating myocardial ischemia and 8S8e&Sing viability
provides i.nfonnation on the global left ventricular .reaponse to
exercise regional wall motion is analyzed at rest and with stress
used for valvular heart disease evaluation
Cardiology and CV SUJ'8ery QJ
"' T111p00ln T (HJ!y rap.fui!Gnl
Figure 1 3. Cardiac EnQII'Ia
u. .... .,..llllrilnli: ..... ina. E'lllllllllld ,......_.,
ACIII.,._ (UIBj N1111004; 350;641-64 .. Pro!plc:IM. rlllbrDd
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ptpidilll'llbnclild .-.!. a.-: TIIIIIDdld!IIQII .. dtDIII colt cl
1l8lln.m. llldl: Mlllilll1inaiDIIDirga- sllnr il1111 iiDw6on Pf
wlallillft'4ll'ld wil11111 c:allniiiJCiq) 18.0 w. 11.0 - 1111
iniiMnti:ll PIP l$541 D vs. $1l64, p-0.005). lllllftln.1111
meu.nnartof a.-llllrillllic JIIPiill 11tapblllldiUIIM en.
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al ii-IPe rninllic ,. ..._ DniM cntllld IIICI8vallll 111111 CUll af
lniiDIId.
-
CIO Cardiology and CV Surgery
...,,
Most CDIIIIIIODiy Ulllll T.-lmill ltnw Tell: PnrtDoall The lkucl
PrltDcol - 7 stage test
with each stage lasting 3 minutes. Wdh each IIUCCNSiVIJ llbge,
1he 1relldmll increa- in both speed IJid gredient.
For old individuals or those with limibJd exen:ise capacity:
eilher The Modifild Bruce or The Modihd Naughtun l'rotDcol
...,,
Important ContrlindicatiDns ta Exen:ile luling Acute Ml, eartic
dissection,
pericerditis, myocarditis, pumanary embalism
Severe AS, arllllilll HTN to exen:iaa adaqulll&ly
...,,
Most lmpartut Prognostic Futort il Exercise luling Sldlpmsian ST
ahrVIIIion liload PfiiSII8 compensetion
...,,
Dulal Trudmill Saare Weighted index combining: 1 . TraadmiU
IIX8rcise time using
standard Bruce protocol 2. Maximum net ST segment deviation
(dlpmsion or eiiVIItion) 3. Exen:in-inducad angina Provides
diagnostic 1nd prognostic information (IIUCh u 1 -y&lr
morlllity)
.... ,
Pltients with normal parfusion 51udi81 ltpukstmlhiVIJa incidanca
of dalth or nonfatal Ml and are 1hus often spared furth inVIIsive
evaluation for assessment of their symptoms.
Cardiac Diagnostic Teats Toronto Notes 2011
Contrast Echocarcl iography contrast agents injected into the
bloodstream to improve imaging of the heart conventional agent:
agitated saline (contains microbubbles of air) allows visualization
of right heart and intracardiac shunts, most commonly patent
foramen
ovale (PFO) and sometimes intrapulmonary shunt newer contrast
agents are capable of crossing the pulmonary bed and achieving left
heart
opacification following intravenous injection; these contrast
agents improve visualization of endocardial borders and enhance
evaluation of ejection fraction
Stress Testing exercise testing is a cardiovascular stress test
using treadmill or bicycle exercise with
electrocardiographic and blood pressure monitoring guidelines
for use:
patients with intermediate ( 10-90%) pretest probability of CAD
based on age, gender and symptoms
complete RBBB ST depression 10 mmHg from baseline despite an
increase in workload,
when accompanied by other evidence of ischemia moderate to
severe angina ST elevation (> 1 mm) in leads without diagnostic
Q-waves (other than Vl or a VR) increasing nervous system symptoms
(e.g. ataxia, dizziness, or near syncope) signs of poor perfusion
(cyanosis or pallor) technical difficulties in monitoring ECG or
systolic blood pressure patient's desire to stop sustained
ventricular tachycardia
Interpretation the most commonly used ECG criteria for a
positive exercise test: mm of horizontal or
downsloping ST-segment depression or elevation (at least 60 to
80 msec after the end of the QRS complex)
NUCLEAR CARDIOLOGY myocardial perfusion imaging {MPI) with
ECG-gated single photon emission computed
tomography (SPECT), using radiolabelled tracer role in
evaluating myocardial viability, detecting ischemia, and
simultaneously assessing
perfusion and left ventricular function the degree of severity
shown on the scan reveals the likelihood of further cardiac event
rates
independent of the patient's history, examination, resting ECG,
and stress ECG result often denoted as MIBI scan with reference to
radiolabelled tracer user exercise
treadmill test (unless contraindicated) vasodilator stress with
intravenous drugs
dipyridamole (Persantine), adenosine act to increase coronary
flow by vasodilation of arterioles (the resistance vessels)
images of the heart obtained during stress and at rest 3-4h
later fixed defect - impaired perfusion at rest and during stress
(infarcted/hibernating) reversible defect - impaired perfusion only
during stress (ischemic)
.... , Tracers
ACC/AHA zaaz Guidelines for Use Stabbl angina, baseline ECG
abnormalities, post-rwac:IArization assessment. heart h.ilure,
patients Ulllble to exercise, preoperative risk assessment for
patients undergoing nancanl wrgery.
thalliwn-201 (201Tl, a K analogue) technetiwn-99 (99Tc)-labelled
tracer (sestamibi/Cardiolite or hexamibi/Myoview-)
Summary of Stress Testing Exercise ECG
initial evaluation in patients without hard-to-interpret ECGs
who are able to exercise Exercise Stress Echo
when ECG is uninterpretable intermediate pre-test probability
with normal/equivocal exercise ECG post-ACS when used to decide on
potential ef1icacy of revascularization to evaluate the clinical
significance of valvular heart disease
-
'IbroDlo Nota 2011 Cardiac Diagnoslic Testl
Dobutamine Stress Echo in patients unable to aerdse, with the
same lndlcatlons as aerdse stress echo to assess tissue
viability
o Exeidse Myocardial Perfusion Imaging (MPI) when ECG is
uninterpretable intermediate pre-test probability with
normal/equivocal exercise ECG in patients with previOUI imaging
whose symptoms have changed to diagnose iachemla
Dipyridamclel.Adenosine MPI to diagnose CAD in possible ACS
patients with non-diagnostic ECG and negative serum
biomarkers when ECG is uninterpretable due to LBBB or V-paced
rhythm in patients unable to aercise, with the same indications as
exercise :MPI
Cardiac Catheterization and Angiography o invasive: catheters
are introduced peu:utaneously intJJ arterial and venous circulation
under
conscious sedation and contrast ia injected arterial access most
commonly through the femoral artery. radial approach gaining
favour especJally for obese patients and outpatients dependent
on driving and ambulation (occupational requirements)
venous access through the femoral vein or internal jugular vein
same day procedure as outpatient
indications for prehospitalization: anticoagulation therapy,
renal failure, diabetes, contrast allergy
catheterization permits direct meamrement of intracardiac
pn:llllures, transvalvular and mean peak pressure gradients, valve
areas, cardiac output, shunt dam. oxygen saturations, and
visualization of coronary arteries, cardiac chambers and great
vessels
Right Heart Catheterization (Swan-Ganz catheter) right atrial.
right ventricular. pulmonary artery pressures are recorded o
Pulmonary Capillary Wedge Pressure
obtained by advancing the catheter to wedge into the di.stal
pulmonary artery records pressures measured from the pulmonary
venous system in the absence of pulmonary venous di&ease, will
rdlect left atrial pressure
Left Heart Catheterization systolic and end-diasto1ic pressure
tracings recorded; left ventricular size, wall motion
and ejection fraction can be assessed by injecting contrast Into
the left ventricle (left ventriculography)
cardiac output (measured by the Pick oxygen method or the
indicator dilution method) Coronary Angiography
Cardiology and CV Surgery Cll
,, ,
liellltlwlly 1111 &peclllclty Ill Vll'loul 111Mtlldq
Exarcila ECG (Sn 611; Sp 71) Stms (Sn 71; Sp 881 PET -..inu!Sn 81;
Sp 82) MIBI acannllg (Sn BB; Sp 77)
coronary vasculature accessed via the coronary ostium ..... 1
conttaindicated with severe renal failure (due to contrast agent
toxicity), must check renal status ,}---------,
1-......... 2 -lnflnlplcal
- AnllrDipical i - Anllnlllllal
Figure 1 4. Coronary Angiogram Sclllmltic {RCA = right coronary
artBry, AM = acuta marginal. LAD = left antariar dascending, OM =
obtuse marginal! Prognosticators o angiograpbic variables may
provide valuable information regarding lesion severity,
complexity,
locatl.on and progno!lis
ACCIAHA 2002 .._ .. lllllld .. lndlml- fur c-ay Ana-...,
Disebling (CCS c:luses Ill end M
chronic llllble enain diiPite medical tharapy
critaia on clilir:ll essmment or nor.-ilvaiva Wli1;
SUdden cardiac dlllllh. ..-icu vanbi1D1r arrhythmia. or CHF
Uncartlin dilpsis or prognosisaftar non-invuive tailing
lllllbilily to IRiarvo nor.-inv1111iva liSting
"
c__,- Gold standlrd far localizing nl q111ntifyilg CAD.
,.--------------. Hamodynlmicaly significant llanosis is
dllil'lld q 711'1 or more narrowing Gf1he dilnllblr.
-
Cl2 Cardiology and CV Surgery Cardiac Diagnostic Tests/
Arrhythmias Toronto Notes 2011
Diagnostic Catheterization outcomes related to complications for
diagnostic catheterization should be < 1% procedure related
complications: vascular injury, renal failure, stroke, MI
mortality rate 0.1-0.2% inadequate diagnostic procedures should
occur in far fewer than 1% of cases provocative pharmacological
agents can be used to unmask pathology
fluid loading may unmask latent pericardia! constriction
afterload reduction or inotropic stimulation may be used to
increase the outflow tract
gradient in hypertrophic cardiomyopathy coronaryvasoreactive
agents (e.g. methylergonovine, acetylcholine) a variety of
pulmonary vasoreactive agents in primary pulmonary hypertension
(e.g. oxygen,
calcium channel blockers, adenosine, nitric oxide, or
prostacyclin)
Contrast-Enhanced CT Coronary Angiography fast ECG-synchronized
multi-slice CT image acquisition in the heart has enabled
non-invasive
imaging of the coronary arterial tree often used to assess
coronary artery and previous graft stenosis/viability that could
not be seen
during coronary angiography sensitivity= 85%, specificity= 90%
for the diagnosis of obstructive coronary disease with
>50% stenosis
Magnetic Resonance Imaging (MRI) offers high spatial resolution,
eliminates the need for iodinated contrast, and does not
involve
exposure to ionizing radiation valuable in assessment of
congenital cardiac anomalies, abnormalities of the aorta, and
assessment of viable myocardium
CARDIAC DISEASE
Arrhythmias Mechanisms of Arrhythmias
(I} Alterations in Impulse Fonnation 1his can occur due to: A.
Abnonnal Automaticity
automaticity is a property of certain cardiomyocytes to
depolarize themselves to their threshold voltage so as to
spontaneously generate action potentials in a rhythmical
fashion
under normal circumstances, only cells at the specialized
conduction system (SAN, A VN and ventricular conduction system)
exhibit natural automacity and are thus pacemaking cells - the
automaticity of these pacemakers can either become abnormally
increased or decreased
cells in the myocardium outside the conduction system in disease
(e.g. post-MI ventricular ischemia) may inappropriately acquire the
property of automaticity and contribute to abnormal depolarization.
If these ectopic generators depolarize at a rate that is greater
than the SAN, they assume pacemaking control and become the source
of abnormal rhythm
automaticity can be influenced by: neurohormonal tone
(sympathetic and parasympathetic stimulation) abnormal metabolic
conditions (hypoxia, acidosis, hypothermia) electrolyte
abnormalities drugs (e.g. digitalis) local ischemia/infarction
other cardiac pathology
this mechanism is responsible for the accelerated
idioventricular rhythm and ventricular tachycardia that often
occurs 24 to 72 hours post myocardial infarction
-
'IbroDlo Nota 2011
B. Trigcred Adtrily due to AftcrdepoJ.arizations There are two
types of triggered activity: 1. Early AfterdepolarhatioM
occur in the conten action potential prolongation consequence of
the membrane potential becoming more positive during repolarization
result in self-maintaining depolarizing oscillations of action
potential, generating a
ta.chyarrhythmia. basis for the degeneration of QT prolongation.
either congenital or acquired. into Torsades
de Pointe& 2. Delayed Afterdepolarizaons
occur after the action potential has fully repolarized, but
before the next usual action potential. thus called a delayed
afterdepolarization
commonly occurs in situations of high intracellular calcium
(digitalis intoxication, ischemia) or during enhanced catecholamine
stimulation
(II) Alterations in Impulse Conduction 'Ibis can occur due to:
A. Re-Entry C1rcuit8 (see Figure 15 for detailed descrl.ptl.on)
the presence of self-sustaining re-entry circuit causes rapid
repeated depolarizations in a region of myocardium
e.g. myocardium that has infarcted and become ischemic will
consist of non-excitable and partially excitable zones which will
promote the fOrmation of re-entry circuits
Rgurt 15. Mecllanlun of Reentry Requii'8B both unidirectional
block (11and slowed ratrugrada cDnlbction (21. When an action
potential raachas a division in the conduction path (anywhara in
the myacardiuml, the impulse proceeds II'Ound and stirrdates dstal
rnyocmdium. If the action patantial propagatas through a block
(rafractary tissual in 1ha retrograde dirac-tian but nllt in 1ha
foTward diraction,. unidiFICtianal block is p111S1nt 111. This can
occur as a rasult af calular dysfunction with changes in cellwar
refractoriness. Slowed retrograde conduction of the action
potential'lllrough B (datted lne) encounters excitable tissue in A
because these myacytes have had sufficient time to repolarise by
this time paint. and now the impulsa is free to excite A again thus
generating a raantJy circuit.
B. Conduction Block ischemia, fibrosis, trauma and drugs can
cause transient, permanent, unidirectional or
bidirectional block most common cause of block is due to
refractory myocardium (cardiomyocytes are in
refractory period or zone of myocardium unexcitable due to
fibrosis) if block OCCill'll along the specialized conduction
system, distal zones of the conduction
system can assume pacemaking control conduction block can not
only lead ro bxadyaudia, but also tachyc:ardl.a when impaired
conduction leads to re-entry phenomenon C. Bypua 'lradl
normally the only conducting tra
-
Cl4 CardiologyandCVSurgery
....
Bnulyanhythmias Examples
lin Arrhytbmi1 Normal P W.V., 1111riatian of !he P-P int8rval by
> 120 msec due to lllll'(ing rate of SA node ......... ry SA":
Seen moru oftun in young lldulb
{
-
'IbroDlo Nota 2011
AV Conduction Blocks 1st Degree AV Block prolonged PR interval
(>200 msec) frequently found o..mong otherwise healthy adults no
treatment required
2nd Degree AV Block some of tbe atrial impulses are not
conducted to the ventricles c:an describe block by ratio ofP waves
to# of QRS (e.g. 2: l, 3: l, 4:1 increases in severity) second
degree AV block is further subdivided into:
Type I (Mobitz I) 2nd Degree AV Block a gradual prolongation of
the PR interval precedes the fallw:e of conduction of a P wave
(Wenc:kebach phenomenon) AV block ls usually in AV node
(proximal)
- triggers (usually reverslble): Increased vagal tone (eg.
following surgery), RCA-mediated ischemia
- not an indication fur temporary or permanent pacing
Fiare 17. Secand D11re1 AV llack with Wencklblch l'llllom8lllln
(Mabib: I) (4:3 canductian)(I.Hd V1) Type D (MobJtz II) 2nd Degree
AV Block.
tbe PR interval is constant; there I& an abrupt failure of
conduct:lon of a P wave AVblock is usually distal to tbe AV node
(I.e. His bundle) increased risk ofhigh grade or 3rd degree AV
block
Figure 1 I. Sacand Dagna AV Black (Mollitz II) (3:2 cand1ctian)
(Lead V1) 2:1 AV Block often not possible to determine whether the
block is type I or type II prolonged or repeated recordings may
clarify the diagnosis
Figure 1 9. 2:1 AV Black (Lead II) 3rd Degree AV Block complete
failure of conduction of the supraventricular impulses to the
ventricles ventricular depolarization initiated by an escape
pacemaker distal to the block QRS can be narrow or wide Ounctional
va. ventricular escape rhythm) PP and RR intervals are constant,
variable PR intervals no relationship between P waws and QRS
complexes (P tltrrJUWl) management (see &ctricalPacing.
C21)
Figure 20. Third Degree AV Block (Comp1818 Heart Blo-*) (Lead
II)
Cardiology and CV Surgery ClS
"' , 'JWe II (llollllz Ill 'r Typa II AV bla'* ilan indiCIIIian
fllr pemwulllt piCina.
-
C16 CardioloBY aod CV Suqp:ry 10ronto Nota 2011
Figura .Z1 . Abill Flutter wid! V.riabla Block
Supraventricular Tachyarrhythmias Presentation for SVT (and
pra-axcltatlon syndromes) symproms can include: palpitations,
dizziness, dyspnea. chest discomfort, presyncopelsyncope me;y
precipitate congestive heart failure (CHF), hypotension, or
ischemia in patients with
underlying disease o untreated tachycardJas can cause
cardiomyopathy (rare. potentially reveraJble with treatment of
SVT's) includes supraventricular and ventricular rhythms
Supraventricular Tachyanhythmlu (SVT) tachyarrhythmias that
originate in the atria or AV junction this term is used when a more
specific diagnosis of mechanism and site of origin cannot be made
characterlzed by narrow QRS, unless there is pre-existing BBB or
aberrant ventr:icul.ar
c:onductl.on (abnormal conduction due to a change in cycle
length) Sinus Tachycardia sinus rhythm with rate> 100 bpm o
occurs in normal subjects with increased sympathet1.c tone
(exerc.l.se, emotions, pain), alcohol
use, caffeinated beverages, drugs (e.g. beta-adrenergic
agonists, anticholinergic drugs, etc.) etiology: fever,
hypotension, hypovolemia. anemia, thyrotoxicosis, heart failure,
MI. shock,
pulmonary embolism, etc. treatment: treat underlying disease;
consider beta-blocker if symptomatic, CCB if beta-blockers
contraindicated Premature Beats o premature atrial contraction
{PAC. Figure 25)
ectopic supraventricular beat originating in the atria P wave
morphology of the PAC usually ditrera from that of a normal sinus
beat
junctlanal premature beat ectopic supraventricular beat that
originates in the vicinity of the AV node P wave is usually not
seen or an inverted P wave is seen and me:y be before or closely
follow
the QRS compleJ: treatment uauall.y not required
Atrial Flutter rapid, :regular atrial depolarization from a maao
re-entry drcuit within the atrium (molt
commonly the right atrium) atrial rate 250-350 bpm, usually 300
bpm AV block UBUally occurs; it may be fixed (2:1, 3:1,4:1, etc.)
or variable etiology: CAD, thyrotoxicosis, MV disease. cardiac
swgery, COPD, pulmonary embolism,
pericarditis ECG: sawtooth flutter wava (most common type of
flutter) in inferior leads (II, m, a VF);
narrow QRS (unless aberrancy) in atrial flutter with 2:1 block,
carotid sinus massage (first check for bruits), Valsalva
maneuver
or adenosine may decrease AV conduction and bring out flutter
waves o treatment
acute: if unstable (e.g. hypotension, CHF, angina): electrical
cardioversion if stable
(1) rate control: beta-blocker, diliiazem, verapamJl, or digoxin
(2) chemical cardioversion: sotal.ol, amiodarone. type I
antiarrbythmics or
electrical cardioversion anticoagulation guidelines same as for
patients with AF (see Alrlal Ftbrlllatlon, C17) long-term:
antiarrhythmic:&, catheter radl.ofrequency (RF) ablation
(success rate dependent
on site of origin of atrial flutter)
Multlfocal Atrial Tachycardia (MAT) irregular rhythm caused by
presence of 3 or more atrial foci (may mimic AF) atrial rate
100-200 bpm; at least 3 distinct P wave morphologies and PR
intervals vary, some P
waves may not be conducted o occurs more commonly in patients
with COPD, and hypoxemia; less commonly in patients with
hypokalemia, hypomagnesemia. sepsis, theophylline or digital.la
toxicity treatment: treat the underlying cause; CCBs may be used
(e.g. diltiazem, verapamil),
beta-blockers may be contraindicated because of severe pulmonary
disease no role for electrical cardioversion, antiarrhythmics or
ablation
-
'IbroDlo Nota 2011
Atrial Fibrilllltion (Af) most common sustained arrhythmia
incidence lnaeases with age (10% of population >80 years old)
symptoms: palpitations, fatigue. syncope and may precipitate or
worsen heart failure may be associated with thromboembolic events
(4%/year In nonvalvular AF) IDitlation
9lng].e circuit re-entry and/or ectopic fod act as aberrant
generatois producing atrial tachycardia {350-600)
impul&e& then conduct irregularly acro&S the atrial
myocardium to give rise to fibrillation in some cases, ectopic foci
have also been mapped to the pulmonary vein ostia and can be
ablatEd
maiutnaoce the tachycardia causes atrial structural and
electropbysl.ol.oglcal remodelling changes that
further promote AF; thus the longer the patient is in AF, the
more difficult it is to convert back to sinus rhythm
the AV node Irregularly filters incoming atrial impulses
producing an Irregular ventricular
response of 75 Ilia ballS Slnia'TIA. (flill')
AFonECG
8.5-1 8.2
aspirin 81-325 daly caurradin (INR 2-3) caurradin IINR 2-3)
no organized P waves due to zapid atrial activtty {350-600 bpm)
causing a cbaotlc fibrillatory baseline
Irregularly Irregular ventricular response (typically
100-lSObpm), narrow QRS {unless aberrancy or previous BBB)
wide QRS compleus due to aberrancy may occur following a
long-short cycle sequence ("Ashman phenomenonj
loss of atrial contraction. thus no wave seen In ]VP, no S4 on
auscultation
Figure 22. Abill Fibrillllion (Laad II) Management (adapted
&om ACC/AHAJESC pidelinal006) Major objectiftl {RACE) 1. Rate
control: beta-blockers, diltiazem, verapamil (in patients with
heart allure: digoxin,
amiodarone) 2. Anti-coaguhn:ion: prevmt thromboembolism
assess stroke risk: determine CHADS2 score in patients with
nonvalvular AF if no risk factors. ASA 81-325 mg dafly I moderate
risk factor, ASA or warfarin (INR2.0-3.0, target 2.5) moderate risk
factors or any high risk factor (prior stroke. TIA or embolism.
mitral
stenosis, prosthetic valve), warfarin 3. Cardioversion
{electrlcal)
if AF 24-48 hrs, anticoagulate fur 3 weeks prior and 4 weeks
after cardioversion if patient unstable (hypotensive, active angina
due 1D tachycardia, uncontrolled heart failure),
should cardiovert immediately 4.Etiology
HTN, CAD, valvular disease, pericarditis, cardiomyopathy,
myocardlti&, ASD, following surgery. PE. COPD, thyrota:ncosls,
SSS (Sick Sinus Syndrome), alcohol ("holiday heart")
may present in young patients without demonstrable disease
("lone .AF") and in the elderly without underlying heart
-
CIS Carcliolosrand CV Surgery A:rrhythmiu 1'oroDio 2011
lnlllllec '2 ......... lbcb .. l'dl*lllll .......
sn61Tr.-.II!MricAt?lcb CGdrn !31:al0081111 llldy: Ccdnn Syarlllic
lllwilw.l ACTs will llrillfirlltmllll m limy rt lllnlla II' tJniaJt
ilchMTi: au.:t. II'IIIMIIDI: Lqtam ... ltiM!Ga wluil --Dibrnl:
lllllnllll. .... dad!, rn,acardll imtlins. llldl: aiJ!Ib!ctt
11111111al ma (OR 0.68, MO.M-0.115). ildlaric lllnlla ((1110.53,
!IS0.41 -ILIB). 1111 r,Qnil: lridi 181:1[11 0.48.115'10.25 - 0.10).
lhlfUIIII fiUigrbtttfilren:e in flld a 111nvfwnnllpiin I Ill 1.18,
1M 1..20 -3.28). ........ wufarin enWcra. bU - na118Gite rill!: d
lillllily II' nu1llly 1111 llf'li. s9fl1811 imlcranillilmlnlllgl
rill 1111 PlniiiDid " bnit fir IIIHo!QIIiPiflll-
.... ' , .. lhe cntid llllltiGB i1111lually a cOIIIbml prenura
diral:lad pollariorly against 1hl CIIV!id artav for 5-10 11conds..
Nwr{lliltlln for bnihl .... palpation.
Additio1111l Management Pointa Regarding Atrial Fibrillation
recent studies of patienb with atrial fibrillation suggest that
there is no difference in long-term
survival when treating patients with a rhythm-control ver8118
rate-control strategy however, many patients with a significant
underlying structural heart lesion (e.g, acute MI.
history of congestive heart fallure), valvular lesions (mitral
stenosis, mitral regurgitation, aortic stenosls), hypertrophic
cardlomyopathy, cardJ.ac amyloid. other cardiomyopathies,
pericardial disease, congenital heart lesions) will not tolerate
atrial fibrillation well (since many dependent on atrial kick.) and
these patients should be cardiaverted (chemical or electrical) as
soon as possible
Newly Discovered AF anticoagulants may be benefi.dal ifhigb.
risk for stroke lf the episode is self limited and not associated
with severe symptoms. no need for
antlar.rhythmic drugs lf AF persists, 2 options:
1. rate control and anticoagulation {as indicated above) 2.
cardioversion (as above)
Recurrent AF/Pennanant AF lf episodes are brief or minimally
symptomatic, antiarrhythmic drug may be avoided; rate
control and anticoagulation are appropriate patients who have
undergone at least one attempt to restore sinus rhythm may remain
in AF
after recurrence: permanent AF may be accepted (with rate
control and antithrombotics as indicated by CHADS2 score) in
certain clinical situations
if symptoms are bothersome or episodes are prolonged,
antiarrhythmic drugs should be used no or minimal heart disease:
ftecainide, pmpafenone or sotalol LV dysfunction: amiodarone CAD:
beta-blockers. amiodarone
AV Nodal Re-Entrant Tachycardia (AVNRT) re-entrant clrcuit using
the dual pathways (Cut conducting beta fibres and slow
conducting
alpha fibres) within or near the AV node; often found in the
absence of structural heart disease; cause is commonly idiopathic,
although familial AVNRT has been reported
sudden onset and offset fast resuJar rhythm; rate 150-250 bpm
usually initiated by a supraventricular or ventricular premature
beat AVNRT accounts for 60-7096 of all paroxysmal SVTs retrograde P
waves may be seen but are usually lost In the QRS complex
treatment
acute: Valsalva or carotid massage. adenosine is first choice if
UDreSponsive to vagal maneuvers; if no response, try metoprolol,
digoxin, diltiazem; electrical cardiaversion if patient
hemodynamically unstable (hypotension, angina or CHF)
long-term: lst line: beta-blocker, diltiazem, digoxin, 2nd:
anti-arrhythmic d.nJw! (flecainide. propafenone), 3rd: catheter
ablation
2. An alrial pranlllura bllllt (APBJ llflar 11narmlll deponing
bllld conducu through A
(ainCII npallrilad) but nat B (still rafractury -11111 proUina
unidirec:tiallll block)
lha i11110181nMIIa along A and n111ChB1 the diltlll and of B
which hu now npalarilad, allowing
18?rogl'lfle coiiiM:Iian to IIS!IIblish a18811?ry circuit i
E
1. for AVNRT: Praunce of fulllld algw tnll:ll in AV node
F'ra Z1 Macllani1111 far AV Nollll A..&try
12 :::E i 0
-
'IbroDlo Nota 2011
Pre-Excitation Syndromes refer to a subset of supraventricular
tachyarrbythmiu, mediated by an accasory pathway, which
c:an lead to vmtricular pre-excitation Wolff-Parkinson-White
fWPW) Syndrome congenital defect present in 1.5-2/1000 of the
general population an accessory conduction tract (Bundle of Kent;
can be in right or left atrium) abnormally allows
early electrical activation of part of one ventricle impulses
travel at a greater conduction velocity across the Bundle of Kent
thereby effectively
'bypassing' AV node since the ventricles are a.ctivated earlier,
the ECG shows early wntricu1ar depolarization in the
furm of initial slurring of the QRS complex - the so called
delta wave atrial impulses that conduct to the ventricles through
both the Bundle of Kent and the normal
AV nodeJHis-Purkinje system generate 11 broad "fusion complex"
ECG features ofWPW
PR Interval 200 bpm) and the QRS complex
widens treatment: electrical cardioversion. IV procainam!de or
IV amiodarone
do not use drugs that &low AV node conduction (digoxin, beta
blockers) as this may cause preferential conduction through the
bypass tract and then precipitate VF
long-term: ablation of bypass tract when possible AV ReEntnmt
Tachycardia (AVRT) re-entrant loop via accessory patbwa.y and
normal conduction system initiated by a premature atrial or
ventricular complex orthodromic AVIIT: stimulus from a premature
romplatravds up the bypass tmct 0/ID A) and
down the AV node (A to V) with narrow QRS complex (no delta wave
because stimnlus travels tluough normal conduction system)
comprille& 95 percent of the reentrant tachycardias
associated with WPW syndrome antidromic AVRT: more rarely the
stimnlus goes up the AV node (V to A) and down the bypass
tract (A to V); wide and abnormal QRS as ventricular activation
is only via the bypass tract treatment
acute: similar to AVNRT acept avoid long-acting AV nodal
blockers, e.g. digoxin and verapamil
long-term: for recurrent arrhythmias, ablation of the bypass
tract Is recommended drugs such as flecalnide and procainamide can
be used
Ventricular Tachyarrhythmias Premature Ventricular Contraction
(PVC) or Ventricular Premature Beat (VPB) QRS width >120 msec,
no preceding P wave, bimrre QRS morphology origin: LBBB pattern =
RV site; RBBB pattern = LV site PVCs may be benign but are usually
signifi.c:ant in the following situations:
consecutive = VT) or multiform (varied origin) PVC falling on
the T wave of the previous beat ("Ron T phenomenonj: may
precipitate
ventricular tachycardia or VF Accelerated ldloventrlculer Rhythm
ectopic ventricular rhythm with rate 50-100 bpm more frequently
occurs in the presence of sinus bradytardia, and is easily
overdriven by a faster
supraventricular rhythm frequently OCCill'll in p11tientll with
acute myocardial infarction or other types ofheart disease
(cardiomyopathy. hypertensive. valvular) but it does not affect
prognosis and does not usually require t:reat:ment
CardiologyandCVSuqery Cl9
a.d.tK.nl Can IDiilll in rVIt
or laft ha.t
,, I J ..
C YOII'III M.Kim ZD11
Figu111 24. Acceuary pathway caniiiUGiian in WPW causes 8llly
venbiciAr actintian lllna tD tiJa appe .. nca al 1 daltB wave
{llurred gpstrelre of tha DRS) a tha ECG Wore unll canduction
occurs acraa the AVN
l'nlmature VenbiciW CGntractiCII !PVC)
Pr .. urtura Alrial ConiiKiion (PAC) NDIB: Thil dilgrlm 111D
show& rr..tedT--
Figu111 ZS. PVC (with bigaminy pattern) 11'111 PAC
-
C20 Carcliolosrand CV Surgery 1'oroDio 2011
'' , Arrl!rlllnlll IIIII llay l'rMIIIt U I 1M4t lUll
'lllchyoanla Vantriculllr illl:hyaldill SVT with ab..-.nt
conduction (1'111
rell18d) SVTwith prwuilting BBB or
nlllllp8cific iltmlnlric.ar condulrtiDn d8tilct
AV cordlction through a bypaN tnllrt in Wf'W plllianb wring ..
lllrilll tachywlhythmia (a.g. lllrilll flllt8r,
atrialllll:hyaldia)
AniDIImic AVRT il Wf'W pdanbl
Venb'ic:ular Tac:hycardia (VT) 3 or more consecutive ectopic
ventricular complexes (Figure 26)
rate >100 bpm (usually 14{)..200) ventricular flutter: if
rate >200 bpm and complexes resemble a sinusoidal pattern
'"8U8tal.ned vr if it lasts longer than 30 sec ECG characteristics:
wide regular QRS tachycardia (QRS usually >140 msec);
AV dJssodatlon; bizarre QRS pattern. Also favour Ih ofVT: left
axl.s or right am deviation, nonspecific intraventricular block
pattern, monophasic or bipbasic QRS in Vl with RBBB, QRS
concordance in Vl-V6
occasionally during VT supraventricular impulses may be
conducted to the ventricles genenrting QRS complexes with normal or
aberrant supraventricular morphology ("ventricular capture") or
sUDUilatl.on pattern ("fusion complexes")
m.onomorplW: VT identical complaes with uniform morphology more
common than polymorphic VT typically result from Intraventricular
re-entry drcuit potential causes: chronic infarct scarring, acute
MI/isdtemia, cardiomyopathies, myocarditis,
arrbythmogenic right ventricular dyapluia, idiopathic, drugs
(e.g. cocaine), electrolyte disturbances
polymorphic VT compleus with constantly changing morphology,
amplltude, and polarity more frequently aasodated with hemodynamic
instability due to faster rates (typically
200-250 bpm) vs. monomorphic VT potential causes: acute
myocardial infarction, severe or silent ischemia, and
predisposing
facoors fur QT prolongation (see below in Torsades de Pointes)
treatment
sustained VT (loDger than 30 seconds) is an emergency, requiring
immediate treatment hemodynamic compromise - electrical
cardioversion no hemodynamic compromise- electrical cardioversion,
lidocaine, amlodarone, type Ia
agents (procainamide, quinidine)
F'1111r1 26. Ventricullr Tachycanla(MDDomurphic) Tabla 4. Wida
Camplax Tachycanlia: Cluaa fDr Diffarallilling VT n. SVT with
Abarrancy*
PresBJiir.l S\'llpbml Hislay a! CAD and praviaus Ml Plft&cal
xlm
Cslllllll y WIIV8I YariableS1
c.utid sinus IIIIIS\111111!/Dnosile tllminltalardlytlmia
Nat helplul vr VT vr SVT""
AV clssacidian Clplure or flllilll QIIS widlh > 1 40 msa:
Exbwna axis daviati111
(left or rVt sLperior axis) Fositive ORS CliiCOrdln:e
(A WIV8 ICI'OII chast: llllds) Nagltiw QIIS concordance
{S WIIV8 acroa chest leads) Axis an11ythmia
"H 1111i111t >8511111!11iiM Mill' llllllcllnl1art lillllltlhm
dalce II Vf >95'1. "Mrt tlmiwle vr iliiiiiW _..willl no
IIIUcllnlhiWI diaa Torsadea de Polntes
vr vr vr VT vr May suggast: vr vr (polymalplic)
a variant of polymorphic VT that occun In patients with baseline
QT prolongation- "'twisting of the points" (Figure 27)
looks like usual VT acept that QRS complexes "rotate around the
baseline" changing their axis and amplitude
vmtricular rate greater than 100 bpm. usually 150-300 bpm
etiology: patients with prolonged QT intervala are predisposed
congenital long QT syndromes drugs- e.g. Class lA (quinidine),
Class Ill (sotal.ol), phenothia.zl.nes (TCAs), erythromycin.
quinolones, antlhistam.ines electrolyte distw:bances -
hypokalemia, hypomagnesemia nutritional defidend.es causing above
electrolyte abnormalities
treatment IV magnesium, temporary pacing, isoproterenol and
correct underlying cause of prolonged QT, electrical cardioversion
if hemodynamic compromise
-
'IbroDlo Nota 2011
Figura 27. Tarud da Pailtal Ventricular Abrlllatlon (VAb)
chaotic ventricular arrhythmia, with very rapid irregular
ventricular fibrillatory waves of
varying morphology {Pigure 28) terminal event, unless advanced
cardiac life-support (ACLS) procedures are promptly init:i..ed
ID maintain vent:ilation and cardiac output. and electrical
defi.brillation is carried out most frequent cause of sudden death
refer to ACLS algorithm for complete therapeutic guldellnes
J L,. ,; 1 r 'f '":1 Figura Zl. v..bic .. ar Fir..lltian
Electrophysiology (EPS) Studies invasive test fur the
investigation and treatment of cardiac rhythm disorders using
iotn!cardi.ac
catheters provide detailed analysis of the arrhythmia mechanism
and precise site of origin when ECG
data are nondiagnostic or unobtainable bradyarrhytbmias: define
the mechanisms of sinus node dysfunction and localize site of
AV
conduction block. tachyarrhythmias: map fur possible ablation or
to assess indudbllity of ventricular tachycardia
Electrical Pacing the decision to implant a pacemaker usually is
based on symptoms of a bradyarrhythmia or
tachyanhythmia in the setting of heart: disease Pacemaker
Indications SA node dysfunction (most common): symptomatic
bradyt:ardia hemodynamic instability
common manifestations include: syncope. near syncope. transient
Ught:headed:nes. or severe fatigue
SA node dysfunction is commonly caused by: intrinsic disease
within the sinus node (e.g, idiopathic degeneration, fibrosis,
ischemia, or surgical trauma), abnormalities in autonomic nervous
system function. and drug effects
AV nodal-infranodal block: Mobitz II, complete heart block
Pacing Techniquea temporary: transvenous (jugulaJo subclavian.
femoral) or eDernal pacing permanent: transvenous iniD RA, apex
ofRV or both
can sense and pace atrium, wntricle or both new generation: rate
responsive. able to respond to physiologic demand biventrlcular
Tallie 5. Pacemakar Nonaclature 1'111111111 I I'DIIIIal I
CllanOr paced ChltM lensed 0 = Nana 0 = None A = AlrUn A= Atriun v
= v.ntri:IIJ v = Ventricle D = lklai(A+V) D =Dual (A+V)
1'111111111. Reapcnae tD 1181'11ing 0 =None I= lnhlitad T =
Tri!prad
examples of commonly used pacemakers
I'DIIIIIIIIV Pnlpnmability 0 =None R = Rata rnoct.da1im
Tactryanhythmia como! 0 = NIIIB P = Paca S =Shock D = Dual
(P+SI
VVI: single lead in ventricle. pacemaker inhibited in response
to a sensed beat in ventricle; protect patient from bradycardia
DDD: separate leads in atrium and ventricle; pace atrium if
atrium does not contract; once an atrial event has occurred
(whether paced or native) device will ensure that ventricular
contraction follows; device is inhibited in the presence of sinus
rhythm and normal AV ronduction, provides physiologic pacing
Cardiology and CV Surgery Clt
-
C22 Cardiology and CV Surgery Arrhythmiu/lschem.ic: Heart
Disease (IHD) Toronto Notes 2011
................... c.d ..... t.AIUII wilb Lllt'IIIIMidu .,..
o,M:tilll AnnllllemMed21X11; 1 47:25162 Studr: Mela-!Mw of 12 RCTs
used for lmpilnllbll CltdiMIW llllillillltDr (ICDI mcy, 5 RCTs IUid
48 DbseMdilllll Allfiesfor 111d 21 RCTs1nd 43 DbnmliDI'III sludies
for Sllely rMiw. 8516 b' ICDeflicq 26 840 far ..r.ty IIYiiiW Ylitb
11ft Wll1lricUir ljac:tian hlction Qllntlllle Cardiomler Delldllw
implllrotian. Aklllle martll!y lllllllvne eveJ'G a.ulll: ICDs
radUCid morlllly by 20'Jo 11 =44.4\IMI!grnlnt nMb:lian (54\l in
suddan Clldi.: dlllh 1Q. 37\. 63%; hid I rab:ed relltiw risk rl
0.54 fur ll.ggse mllltJIIy - RCTs (CI 0.43 D.58.11=60.4llj.llltM of
success of lCD n,lllllllian were 99\ ta 98.8% 99.3'11j willla 1 .2\
(CI O.B 1.5\1 clwa ofperiirnpllllllltian
COIIII*Itialls!pel'100patient-yam)WIII'II: 1.4(CI 1.5(CI1.31.811ead
prablllrl; O.i (CI 0.5 0.111 ilflmt sill irlaclian; and 19.1 (CI 1U
22.01 il1l!llllllPiJII dilclllrgls il
RCTI111111111'1tSofU(CI4.5-5.3Iilllfiiii'Dilril il DbaaMIIilllll
ftldiiS. ICDs 11e saltllld &lleciNe in rWilg morlllly il aclil
]lltilra l'lilll LV iYIIaic dylb1cliDn. but cany l!irP'i1311rilb of
inlpJIIIIJirilla 6sdi1JQ8I.IiiiNncls RCTsllld
Dlialrvatioraln.danwthatirnp!Md risk lll'ltilicllion of pllim lillY
Utlw impiiMI lllll:amlld llll!CIIIIImsa Milts.
Implantable Cardioverter Defibrillators (ICDs) sudden cardiac
death (SCD) usually results from ventricular fibrillation (VFib),
sometimes
preceded by monomorphic or polymorphic ventricular tachycardia
(VT) ICDs detect ventricular tachyarrhytlunias and are highly
effective in terminating VT NFib and
in aborting SCD several studies demonstrate mortality benefit
vs. antiarrhythmics in 2 prevention (AVID,
CASH,CIDS) benefit fur 1 o prevention of SCD in patients with
ischemic and non-ischemic cardiomyopathy,
depressed left ventricular ejection fraction (LVEF), prolonged
QRS see Heart Failure, C32 for current treatment
recommendations
Catheter Ablation Techniques radiofrequency (RF) energy: a
low-voltage high-frequency form of electrical energy (similar
to
cautery). RF energy produces small, homogeneous, necrotic
lesions approximately 5-7 mm in diameter and 3-5 mm in depth
Indications paroxysmal SVT
A VNRT: accounts for more than half of all cases accessory
pathway (orthodromic reciprocating tachycardia): 30% of SVT
re-entrant rhythm, with an accessory AV connection as the
retrograde limb corrected by targeting the accessory pathway
atrial flutter: flutter focus in RA atrial fibrillation:
potential role fur pulmonary vein ablation ventricular tachycardia:
commonly arises from the right ventricular outflow tract and
less
commonly originates in the inferoseptalleft ventricle near the
apex (note: majority of cases of VT are due to scarring from
previous MI and cannot be ablated)
Major Complications approximately 1% of patients death: 0.1-0.2%
cardiac: high grade AV block requiring permanent pacemaker,
tamponade, pericarditis vascular: hematoma, vascular injury,
thromboembolism, TIA/stroke pulmonary: pulmonary embolism
Ischemic Heart Disease (IHD) Epidemiology most common cause of
cardiovascular morbidity and mortality atherosclerosis and
thrombosis are the most important pathogenetic mechanisms
male:female ratio= 2:1 with all age groups included (Framingham
study), 8:1 for age 70 peak incidence of symptomatic HID is age
50-60 (men) and 60-70 (women) for primary prevention of ischemic
heart disease, please see Family Medicine, FM17
Tabla &. Risk Factors for Atharosclerotic Heart Disease
Mljar Rislr: FIU:bn Smoking Diabetes mellitus {DM) Hypsrbn&ion
(HlN) Ftrnily history (FHx) Dl Ml
Fim degree male rei alive
-
Toronto Notes 2011 Ischemic Heart Disease (IHD)
HTN Hypercholesterolemia Cigaratl8s Endothelial injury
Macrophage influx --------+Foam calls Dlcidized LDL ... Flllty
slruaks 4Jid core
Growth -----------+AthertJIIIil ..
Lumen murowilg Ruplln
Figure 29. Pathophysiology of Atherosclerosis
Chronic Stable Angina Definition
Endothelial damage i- Cytoki1as Smooth mu8Cie Fibror cap
CalcffiCIIIion symptom complex resulting from an imbalance
between oxygen supply and demand in the
myocardium factors influencing supply
luminal diameter (most important factor) duration of diastole
(important fur coronary artery perfusion) hemoglobin Sa02
factors influencing demand heart rate contractility wall
stress
Etiology and Pathophysiology decreased myocardial oxygen
supply
atherosclerosis, vasospasm tachycardia (decreased duration of
diastolic coronary perfusion) anemia hypoxemia congenital
anomalies
increased myocardial oxygen demand tachycardia hyperthyroidism
(increased contractility, increased HR} myocardial hypertrophy,
aortic stenosis
Signs and Symptoms typical: retrosternal chest pain, tightness
or discomfort radiating to left ( right) shoulder/arm/
neck/jaw, associated with diaphoresis, nausea, anxiety
predictably precipitated by the "3 E's: Exertion, Emotion and
Eating brief duration, lasting< 10-15 minutes and typically
relieved by rest and nitrates Levine's sign: clutching :fist over
sternum when describing chest pain anginal equivalents: dyspnea,
acute left ventricular failure, flash pulmonary edema
Clinical Assessment history, physical and directed risk factor
assessment labs: Hb, fasting glucose, fasting lipid pro:file ECG
(at rest and during episode of chest pain if possible) CXR
(suspected heart failure, valvular disease, pericardia! disease,
aortic dissection/aneurysm,
or signs or symptoms of pulmonary disease) stress testing (see
Cardiac Diagnostic Tests, CS} or angiography echocardiography
to assess systolic murmur suggestive of aortic stenosis (AS),
mitral regurgitation (MR) and/ or hypertrophic cardiomyopathy
(HCM)
to assess LV function in patients with Hx of prior Ml,
pathological Q waves, signs or symptoms of congestive heart failure
(CHF)
Cardiology and CV Surgery C23
..... , ,
Chronic stable angi1111 is most often due to a fixed siBnosis
clllll8d by an atheroma. Acuts coronary syndromaa ara tha mutt
of
.... , ,
Can.dian Cardion_.., ICCSI hnctillnal C._lilic1tian Df Anatn
Cllst 1: ordinary physical ectivity
(walking, climbing stairs) does not CllllH angina; angina with
rtnnuous, rapid, or prolonged ectivity.
Clla II: slight limitation Df on!ilary activity: angina brought
m > 2 blocks on level or climbing > 1 flight of stair11 or by
emotional rlnll.
Cllss Ill: marked limitation of ordillllry ectivity: engi1111
brought on at
-
C24 Cardiology and CV Surgery Ischemic Heart Disease (IHD)
Toronto Notes 2011
Optilllllhllcallhlpy with ....... Pl:lt. Stllilel:aranuy
.._COURAGE Trill NU.f2007; 356:1503-16 l1udr. lllncloniled.
CCIII1IIIed iilll'oitll me11ian l'llldltim 2287 petimll MID llld
alijeclive IYidara gf llrjiCII"dill ia:larillllld 19iblt
lllhllcoronll'f lll8ly disa11a. 1...-. l'llierQwellllllldonilld 111
IIIC8ive inllnsivl phnllcolagic llllrepy lll1d lillllytl iniiMOOan
Mil orl'oitllout pen:ibreu COI'OOIIV inlllwrDln (Fa).
l'limlryou1comewulkue mollllily IIIII nonfllll mvoCIIIill
inlln:lioa (MQ. Secondlly lllk:ome hid llllillianil mmtJ alllrab,
Ml111d lapiiJimlior1 fDJ ualllbla 11911 willlliiQIIivB bilnltkm.
llelulll:n..wunoliQnifil:lrt._cein prinwy (ooqJSIId hmnllllio:
1.05; 01 Slmldll'f IMI:Oines (hmrd ratio: 1.05; P=0.62) bltwean the
PCIIIId iiiiMitioiiPJPL The PCI P4> hill liJtler Ales of
'-CI.IIIrimlion 114.6Y81Q alfvlkM-11p (lllmd lllie 0.60, P
-
Toronto Notes 2011 Ischemic Heart Disease (IHD)
Acute Coronary Syndromes (ACS) Definition coronary
atherosclerosis with superimposed thrombus on ruptured plaque:
other causes of unstable angina:
coronary thromboembolism (e.g. infective endocarditis,
intracavitythrombus, paradoxical embolism) or cholesterol
embolism
severe coronary vasospasm coronary dissection increased demand
can also contribute (e.g. tachycardia, anemia)
Spectrum of ACS unstable angina (UA)/non-ST elevation myocardial
infarction (NSTEMI) ST elevation myocardial infarction (STEMI)
sudden cardiac death
Investigations history and physical
note that up to 30% of Mis are umecognizc:d or "silent" due: to
atypical symptoms - more common in women, DM, elderly, post-heart
transplant (because of denervation)
ECG,CXR labs
serum cardiac biomarkers for myocardial damage (repeat 8 hours
later) (see Cardiac Biomarkers, C9)
CBC, INR/aPTT, electrolytes and magnesium, creatinine. urea,
glucose, serum lipids draw serum lipids within 24-48 hours because
values are unreliable from 2 to 48 days post-MI
Unstable Angina (UA)/Non ST Elevation Ml (NSTEMI) Definition
syndrome of acute plaque rupture and thrombosis with incomplete or
transient vessel occlusion unstable angina is clinically defined by
any of the following:
accelerating pattern of pain: increased frequency, increased
duration, with decreased exertion, decreased response to
treatment
angina at rest new onset angina angina post-MI or post-procedure
(e.g. percutaneous coronary intervention [PCI], coronary
artery bypass grafting [ CABG]) NSTEMI is clinically defined by
the presence of 2 of 3 criteria:
symptoms of angina/ischemia rise and fall of serum markers of
myocardial necrosis evolution of ischemic ECG changes (without ST
elevation or new LBBB)
acute phase ofUAJNSTEMI risk of progression to MI or the
development of recurrent MI or death is highest in the early
period at 1 to 3 months after the acute phase. most patients
resume a clinical course similar to that
in patients with chronic stable coronary disease majority of
NSTEMis do not result in the development of Q waves
ST Elevation Myocardial Infarction (STEMI) Definition syndrome
of acute plaque rupture and thrombosis with total coronary
occlusion resulting in
myocardial necrosis STEMI is clinically defined by new ischemic
ECG changes plus one or both of ischemic
symptoms and elevated cardiac enzymes ECG criteria (see Approach
to ECGs, CS)
ST elevation in 2 contiguous leads mm in limb leads or nun in
precordial leads) or new BBB (either LBBB or RBBB)
Acute Management of STEMI after diagnosis of STEMI is made, do
not wait for results of further investigations before
implementing reperfusion therapy goal is tore-perfuse artery:
thrombolysis (EMS-to-needle) within 30 minutes or primary PCI
(EMS-to-balloon) within 90 minutes (depending on capabilities of
hospital)
Cardiology and CV Surgery C25
llllii!'IW Bm. I ..,_..illllfln:llll7 JWA 1 118; 2lllt1 Z56-63
The -.,st r.tures 11111 inc:lelse lhe llllllillaad a1 111m
sr...-IIMtion.-n-. c11111 ]llin lldiJting 1o bath the riilt 11111
111ft ann sindlneollly, pre-al111 S3111d The -.,st r.tures 11111
decrease lhe lcllillaad al Ill 111 nDmlll ECG "11011. pluilic
c:lllll!plin, an or Sllbllilg cllalt plil.llld positillnll dl8lt
plin.
TIM I Rillk far UNNSTEMI a..t.lllb 1'11111 lilblriell ri8: fdDrs
fur CAD ICooMI CAD ISIInolis Aspirinu. inplll7da\'J RKint IS24
hrl-. angina ST-segrrert dellillion 0!:0.5 mm iiiCIIIIId Clldlc
rnmbll II& TDIIII'oilll qi0Q11Phy CAD COIOfiiUY lf1lly llseue
NSTIMI nan STIIgllllnllllvllian myaclllill inflln:tian TM
1ilurilalylil in myac:ardilll irOn:tion UA =II!SIIIIIe.,P .lAMA
2UOO; 284:m-842
lf11.tmtnt of NSTEMI IIEMDAN Enolll!larin Morphine Ot Nitnd
-
C26 Cardiology and CV Surgery Ischemic Heart Disease (IHD)
Toronto Notes 2011
a.m lllflldi. NfJM 2006; 354:1417-811 Studr. Pros,ective.
11llllorrized. controlled nUiiclntrllrill. l'ilil* 20,419 prtients
(ITIIIW IQll 60 11- 11111el with Simi wiD W81111C.'1181Uad to
llllargo lbilat,'sis. l'llierQW81111111doniledto IIICIINt litMr
IIIJlllllrin or Wligld bald lllillclioniiJd hlplrin in llddililn
1nd lllndlld thapiel. DIDin: Dedi oroomntnorntal Ml ll diJyl
pasiMit. a-11111: ThecaufOIIeprinlryaull:ame IJCQIII8I( ""' altai
in tile IIIOXI()Irin compll1d witli those wllo received
lllfnlctioalled hq)uin (UI WI. 12.1)!., p
-
Toronto Notes 2011 Ischemic Heart Disease (IHD)
Diqnolis STlMI: lie tr111tment t STEMI: on&&! of
pain
-
C28 Cardiology and CV Surgery Ischemic Heart Disease (IHD)
Toronto Notes 2011
..... , , .. Resting LVEF is a useful progno5tic factor.
Compkmon of Ml CRASH PAD Cardiac Ruplln Anhytlunia Shock
Hypertensionllleart failure Pericardilifll'ulmonary emboli AMuryam
DVT
Poll-Infarction Risk Slntification r + Hiah Risk !30-35%1
Intermediate/Low-Risk 165-70'5\ Prior Ml CHF + Ruc:ummt ll;cllemia
Higll-Risk Arrhy1mia
Non-Invasive Stress T liSting I
l t Ischemia or Poor Functional Sllrtus Cardiac Cathatarization
...----------'
ECHO dorerautirelypost-MI
Figure 31. Post-MI Risk Stratification
Prognosis following STEM I 5-15% of hospitalized patients will
die
risk factors infarct size/ severity age co-morbid conditions
development ofheart failure or hypotension
post-discharge mortality rates 6-8% within first year, half of
these within first 3 months 4% per year following first year risk
factors
LV dysfunction residual myocardial ischemia ventricular
arrhythmias history of prior MI
Teble 8. Complications of Myocerdiellnferction CampliCition
Etiolarw Presentalian Anhythmia t Tachycardia Sinus. AF, VT, VFib
Fm48hrs 2_ Bradycll"dia Sinus. AV block Fm48hrs Myacardill Ruptu ..
1.LV free wall Transmural infarction 1-7 days 2. Papillary
llll&cla MR) Inferior infarction 1-7 days J_ Ventricular
septum(-+ \lSD) Septal infarction 1-7 days SHckfCHF Infarction or
ana.trysm Within 48 hours Post-lnfln:t Angina Persistent coronary
stenosis Anytime
multivessel disease IIICiftlllt Ml Reoccklsion Anytime
Tbrombolmbalism MuraVapicallhrombus 7-10days,
DVT up to 6 months Pail:llditis lnll111111181ory 17 days
(Dnlllllr'l synlhml AutoimmWll! 2-aweeks
+ Nonnal Results + No further tasting
at this tine
Tb .. Pr
See.AnfJythmias, C1 2
Surgery Surgery Surgery lnotropes, intra-aortic balloon pump
Aggressive medical therapy PCI orCABG See above Anticoagulation
ASA
-
Toronto Notes 2011 Ischemic Heart Disease (IHD)
Treatment Algorithm for Chest Pain Chilli Pain +
1. Morphina PAN 2. 0, 3. ASA 162-325 mg cllewed 4. Nitroglycurin
SL 5. ECG 6. CIWdiac Enzymas
... Initial enzymes normal ST aagment deprassion (UA) STEMI No
ischemic ECG cllanges Positiva enzymes with no ECG changes (NSTEMI)
Initially traet asperUA/ Obsstve: 1. Beta-blockllr NSTEMI pm --+ 2.
EIIOX.IIparin (LMWH) Sari& ECGs and enzymas 3. Morphine pm 4.
Oxygan Com;idur
5. ASA [if not alraady given) rspurfu&ion Rucummt pain, 6.
Nitroglycarin IV options _____.. serial studies - Ri1kl111"11ifv
positive .. .. PCI +
Pain resolves, low risk I I High risk I lhrvmbolysis Serial
studies nonnal Hf I GPIIIrlllla intibitor, Post-inWct I Clopidogrel
risk-stllllify+< Stress Test Stress Tell + low risk+ L .. +ve J
Canlilc Ctheterilation I Stress Test .... "1 Corvnary
Revascularization !-VI
Consider other Risk Factor causas of chest pain -ve and
lif&-long
lllti-anginal Seal/6pfuuiat Shf8gy in S1fMI, Figure 3D therapy S
Post-MI Risk Slnttificlfion. FlgU11131
Figure 32. Treltment Algorithm for Chest Pain AdllptBd tram
Cecil fmlllillsotMedir:ine 6th Ed. Andreoli IIIII Clrpelder.
p.1011Z0041with pemimian fram ElseYier
Sudden Cardiac Death Definition unanticipated, non-traumatic
cardiac death in stable patient, within 1 hour of symptom
onset;
ventricular fibrillation is most common cause
Etiology primary cardiac pathology
ischemia/MI LV dysfunction severe ventricular hypertrophy
hypertrophic cardiomyopathy (HCM) AS
long QT syndrome congenital heart disease
Management acute: resuscitate with prompt CPR and defibrillation
investigate underlying cause (cardiac catheterization,
electrophysiologic studies) treat underlying cause anti-arrhythmic
drug therapy: a.miodarone, beta-blockers implantable cardioverter
defibrillator (lCD)
Cardiology and CV Surgery C29
-
C30 Cardiology and CV Surgery Ischemic Heart Disease (IHD)
Toronto Notes 2011
Wltrlllll ... IIIII Stlnll Cin:liRm 21lll8; 111;311&1206
Studr: t.lllla-nysis of RCTs lfld obii8Miional studies. 22 ACTs a
34 abeeMiioall sllllles. 1,47011111 182,1)1 pllilntsil RCTs llld
allleMitianllllbdnmpecMtfiWD llldniiJI p8!QIIInBOUI CUiamy
illaMnion. DNo-EUiilg S1ln1s IDES)-Bale S18IQ IBMSl. Outall:
J11Crill iArction (MI), lf'ld llrgatYIR8IIMitUIIrilltion ._..:
No4ilnlce in mor11ity-bmd betweea DES w. BMS II ACTs. while
e.mtionli stlldillllllawlll iQnificlnttr IIMII in DES-11111ed
patieull (lard rllio (HA) 0.78, p
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Toronto Notes 2011 Ischemic Heart Disease (IHD)
Operative Issues isolated proximal disease in large coronary
arteries (> 1.0-1.5 mm) is ideal for bypass surgery;
small, diffusely diseased coronary arteries are not suitable for
bypass surgery arteries with severe stenoses (>50% diameter
reduction) are bypassed, except those of small
calibre (
-
C32 Cardiology and CV Surgery
',, .. Dlchlllllmles Ill Hurt FaiU8 FOIWllrd vs. Backw1rd
Lift-sided vs. RictTt-sidad Systolic dysfunction vs. Dilstolic
dysfunction Low autput vs. High output
',, .. IIH Ejecdcm FrudDn ta Gnlde LV Dylfnction Grade I (EF
(Normal I Grade II (EF = 40-59%1 Grade Ill (EF = 21-39%1 Grade IV
(EF
Ischemic Heart Disease (IHD)/Heart Failure Toronto Notes
2011
Procedure OPCAB avoids the use of CPB by allowing surgeons to
operate on a beating heart
stabilization devices (e.g. Genzyme Immobilizer) hold heart in
place allowing operation while positioning devices (Medtronic
Octopus and Starfish system) allow the surgeon to lift the beating
heart to access the lateral and posterior vessels
procedure is safe and well tolerated by most patients; however,
OPCAB surgery remains technically more demanding
Indications used in poor candidates for CPB who have: calcified
aorta, poor LVEF, severe peripheral
vascular disease (PVD), severe COPD, CRF, coagulopathy,
transfusion issues (e.g. Jehovah's Witness), good target vessels,
anterior/lateral wall revascularization, target revascularization
in older, sicker patients
absolute contraindications: hemodynamic instability, poor
quality target vessels including intramyocardial vessels, diffusely
diseased vessels and calcified coronary vessels
relative contraindications: cardiomegaly/CHF, critical left main
disease, small distal targets, recent or current acute MI,
cardiogenic shock, LVEF
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Toronto Notes 2011 Heart Failure
Diastolic Dysfunction (impaired ventricular filling) at least
1/3 of all HF patients have nonnal systolic function (i.e. nonnal
ejection fraction);
prevalence higher in older patients increased LV filling
pressures produce venous congestion upstream (ie. pulmonary and
systemic venous congestion) findings: H1N, apex beat sustained,
S4, nonnal-sized heart on CXR. LVH on ECG/echo, normal
LVEF causes of decreased compliance:
transient: ischemia (relaxation of myocardium is active and
requires ATP) permanent
severe hypertrophy (HTN, AS, HCM) restrictive cardiomyopathy
(RCM) MI
High-Output Heart Failure caused by demand for increased cardiac
output often exacerbates existing heart failure or decompensates a
patient with other cardiac pathology differential diagnosis:
anemia, thiamine deficiency (beriberi), hyperthyroidism, A-V
fistula or
L-R shunting, Paget's disease, renal disease, hepatic disease
Etiologies of Primary Insults consider predisposing, precipitating
and perpetuating factors most common causes see sidebar less common
causes of CHF
toxic e.g. anthracyclines, radiation, uremia, catecholamines
infectious e.g. Chagas' disease (common cause in South America),
Coxsackie virus, HIV endocrine e.g. hyperthyroidism, DM, acromegaly
infiltrative e.g. sarcoidosis, amyloidosis, hemochromatosis genetic
e.g. HCM, Friedreich's Ataxia, muscular dystrophy congenital heart
disease metabolic e.g. thiamine deficiency, selenium deficiency
peripartum
Precipitants of Symptomatic Exacerbations consider natural
progression of disease vs. new precipitant always search for
reversible cause see side bar ("HEART FAILED") differential can
also be organized as follows:
new cardiac insult/disease: Ml, arrhythmia, valvular disease new
demand on CV system: hypertension, anemia, thyrotoxicosis,
infection, etc. failure to take medications as prescribed
Tabla 1 2. Signs and Symptoms of Left vs. Right Heart
Failure
Law canlilc output (farwanll
Investigations
Lift Failure Fatigue Syncope Sy&temic hypoten&ian Coal
extremities Slaw capiiiiiY refill Peripheral cyanosis Pulsus
aiiBmans Mitral regurgitatian 83 Dyspnea. orthopnea. PND Cough
Crackles
Right Failure Right heart failure can mimic mast Df the symptoms
Df forward left heart failure if decreased RV output leads to LV
underfilling
Tricuspid regurgitation S3 (right-sidedl Peripheral edema
Bevated .NP with AJR and Kussmaul's sign Hepalllmegmy Publllile
liwr
identify and assess precipitating factors and treatable causes
of CHF blood work: CBC, electrolytes (including calcium and
magnesium), BUN, creatinine, fasting
blood glucose, HbAl C. lipid profile, liver function tests,
serum thyroid-stimulating hormone, ferritin, BNP. uric add
(associated with prognosis ofHF in Seattle HF Score)
ECG: look for chamber enlargement, arrhythmia,
ischemia/infarction CXR: cardiomegaly, pleural effusion,
redistribution, Kerley B-lines, bronchiolar-alveolar cuffing
echocardiography: LVEF, cardiac dimensions, wall motion
abnonnalities, valvular disease,
pericardia! effusion radionuclide angiography (MUGA): LVEF
myocardial perfusion scintigraphy (thallium or sestamibi SPECT)
Cardiology and CV Surgery C33
...._ \ I 9,}-----------------. NIW Yark Hurt ARecidon INYHAI
funeti01111l Cl-ificrion of H.-rt failllnl . a- 1: ordillllry
physical activity
does not ceusa symptoms of HF a- II: comfortBble lit nJSt,
ordinlll'( physicniiiC!ivity rnults in rymptoms a- ID: marked
limitation of ordinary activity: less then ordinary
physicniiiC!ivity results in rymptoms a- N: inability to carry out
any physicniiiC!ivity without discomfort; rymptoms may be pmsnt at
rust
..... ' , .,.-----------------, What ... thl Fi11 Most
CDIIIIDIRI C.UielofCHF? 1