cardiac arrhythmias

Cardiac Cardiac tachyarrhythmiastachyarrhythmias

Dr Majid ShojaeeDr Majid ShojaeeAssistant professor of Emergency MedicineAssistant professor of Emergency Medicine

SBMUSBMU

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Case 1Case 1 A 30-year-old woman suddenly has rapid A 30-year-old woman suddenly has rapid

palpitations accompanied by chest palpitations accompanied by chest tightness and dizziness.tightness and dizziness.

Previous similar episodes over last 12 Previous similar episodes over last 12 months –usually 20 -30 minmonths –usually 20 -30 min

PR=190/min ,BP=85/55 mm Hg. PR=190/min ,BP=85/55 mm Hg. Otherwise normalOtherwise normal

cardiovascularcardiovascular examinationexamination

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Evaluation and managementEvaluation and management

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Evaluation and managementEvaluation and management signs of increased work of breathing and oxyhemoglobin saturation signs of increased work of breathing and oxyhemoglobin saturation

as determined by pulse oximetryas determined by pulse oximetry.. (O2) (O2) Attach a monitor to the patient, Attach a monitor to the patient, Evaluate blood pressure,Evaluate blood pressure, Establish IV access.Establish IV access. If available, obtain a 12-lead ECG If available, obtain a 12-lead ECG

This(ECG) should This(ECG) should not delay not delay immediate cardioversion if the patient immediate cardioversion if the patient is unstable. While initiating treatment, evaluate the patient’s clinical is unstable. While initiating treatment, evaluate the patient’s clinical status and identify status and identify potential reversible causes potential reversible causes of the tachycardiaof the tachycardia

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What is the differential diagnosis ?What is the differential diagnosis ?

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Supraventricular tachycardiaSupraventricular tachycardia Sinus tachycardiaSinus tachycardia PSVTPSVT Atrial tachycardia (multifocal)Atrial tachycardia (multifocal) Atrial fibrillation / flutterAtrial fibrillation / flutter Junctional tachycardiaJunctional tachycardia Ventricular tachycardiaVentricular tachycardia

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First stepFirst step

STABLE or UNSTABLE?STABLE or UNSTABLE?

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Acute altered mental status, Acute altered mental status, Ischemic chest discomfort, Ischemic chest discomfort, Acute heart failure,Acute heart failure, Hypotension, or Hypotension, or Other signs of shock suspected to be due Other signs of shock suspected to be due

to a tachyarrhythmiato a tachyarrhythmia

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Unstability is Primary or secondary?Unstability is Primary or secondary?

With ventricular rates <150/minute in the With ventricular rates <150/minute in the absence of ventricular dysfunction, it is more absence of ventricular dysfunction, it is more likely that the tachycardia is likely that the tachycardia is secondary to the secondary to the underlying condition underlying condition rather than the cause of the rather than the cause of the instabilityinstability

Rate> 220-ageRate> 220-age Acute onset or gradualAcute onset or gradual JVDJVD Fever, hemorrhage, dehydration…Fever, hemorrhage, dehydration…

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UANSTABLEUANSTABLE

due to a tachyarrhythmia, proceed to immediate due to a tachyarrhythmia, proceed to immediate synchronized cardioversionsynchronized cardioversion

If possible, If possible,

-establish IV access -establish IV access before cardioversionbefore cardioversion

-administer -administer sedationsedation if the patient is conscious. if the patient is conscious.

Do not delay cardioversion if the patient is Do not delay cardioversion if the patient is extremely unstableextremely unstable

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Cardioversion Cardioversion

Synchronized Synchronized

This synchronization avoids shock delivery This synchronization avoids shock delivery during the during the relative refractory period relative refractory period of the of the cardiac cycle when a shock could produce cardiac cycle when a shock could produce VFVF

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Synchronized cardioversion is Synchronized cardioversion is recommended to treatrecommended to treat

(1) (1) unstable unstable SVTSVT, , (2) unstable (2) unstable atrial fibrillationatrial fibrillation, , (3) unstable (3) unstable atrial flutteratrial flutter, , (4) unstable monomorphic (regular) (4) unstable monomorphic (regular) VTVT..

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Rhythm Biphasic (J) Monophasic (J)

AF 120-200 200

A flutter / SVT 50-100 200

Monomorphic VT 100 100

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If a patient has If a patient has polymorphic VTpolymorphic VT, treat the rhythm as VF , treat the rhythm as VF and deliver high-energy and deliver high-energy unsynchronized shocks (ie, unsynchronized shocks (ie, defibrillationdefibrillation doses). doses).

If there is any If there is any doubtdoubt whether monomorphic or whether monomorphic or polymorphic VT is present in the polymorphic VT is present in the unstable patientunstable patient, do not , do not delay shock delivery to perform detailed rhythm analysis: delay shock delivery to perform detailed rhythm analysis: provide provide high-energy unsynchronized high-energy unsynchronized shocks (ie, shocks (ie, defibrillation doses).defibrillation doses).

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STABLE STABLE

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Narrow OR Wide Complex?Narrow OR Wide Complex?> or < 120 msec.> or < 120 msec.

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Regular Narrow QRS Tachycardias therapy

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PR=190PR=190BP=85/55BP=85/55

Her ECG Her ECG

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Vagotonic ManeuversVagotonic Maneuvers

Valsalva maneuver Valsalva maneuver Facial ice pack (“diving reflex” for kids)Facial ice pack (“diving reflex” for kids) Carotid sinus massageCarotid sinus massage

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Valsalva maneuver Valsalva maneuver

The Valsalva maneuver performed in the The Valsalva maneuver performed in the supine position appears to be the most supine position appears to be the most effective vagal maneuver for the effective vagal maneuver for the conversion of reentrant SVT.conversion of reentrant SVT.

For maximal effectiveness the strain For maximal effectiveness the strain phase must be adequate (usually at least phase must be adequate (usually at least l0 seconds), with slowing or conversion l0 seconds), with slowing or conversion seen during the release phaseseen during the release phase

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Facial ice pack (“diving reflex”)Facial ice pack (“diving reflex”)

Placing an ice pack on the face or facial Placing an ice pack on the face or facial immersion in cold water is usually immersion in cold water is usually reserved for infants and is done for 6 to 7 reserved for infants and is done for 6 to 7 seconds with the nostrils held closed seconds with the nostrils held closed (diving reflex)(diving reflex)

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Carotid Sinus MassageCarotid Sinus Massage

Pressure on the carotid sinus and Pressure on the carotid sinus and Baroreceptors. Carotid massage should be Baroreceptors. Carotid massage should be done for 10 seconds at a time,done for 10 seconds at a time,

first on the side of the nondominant cerebral first on the side of the nondominant cerebral hemisphere, hemisphere,

and never simultaneously on both sides.and never simultaneously on both sides.

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Carotid Sinus Massage

Stimulation of carotid sinus triggers baroreceptorreflex and increased vagaltone, affectingSA and AV nodes

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AdenosineAdenosine

6 mg of IV adenosine as a rapid IV push 6 mg of IV adenosine as a rapid IV push through a large (eg, antecubital) vein through a large (eg, antecubital) vein followed by a 20 mL saline flush.followed by a 20 mL saline flush.

If the rhythm does not convert within 1 to 2 If the rhythm does not convert within 1 to 2 minutes, give a 12 mg rapid IV push using minutes, give a 12 mg rapid IV push using the method above.the method above.

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As with vagal maneuvers, the effect of As with vagal maneuvers, the effect of adenosine on other SVTs (such as atrial adenosine on other SVTs (such as atrial fibrillation or flutter) is fibrillation or flutter) is to transiently slow to transiently slow ventricular rateventricular rate (which may be useful (which may be useful diagnostically) but not afford their diagnostically) but not afford their termination or meaningful lasting rate termination or meaningful lasting rate control.control.

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Termination of SVT

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Pregnancy? Pregnancy? Drug history?Drug history? Larger doses may be required for patients with Larger doses may be required for patients with

a significant blood level of theophylline, caffeine, or a significant blood level of theophylline, caffeine, or theobromine.theobromine.

The initial dose should be reduced to 3 mg in patients takingThe initial dose should be reduced to 3 mg in patients taking dipyridamole or carbamazepine, those with transplanted dipyridamole or carbamazepine, those with transplanted

hearts, or if given by central venous access.hearts, or if given by central venous access. Childs:Childs: 0.1 mg/kg0.1 mg/kg

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Side effects with adenosine are common Side effects with adenosine are common but transient; flushing, dyspnea, and chest but transient; flushing, dyspnea, and chest discomfort are the most frequently discomfort are the most frequently observed.observed.

Adenosine should not be given to patients Adenosine should not be given to patients with asthmawith asthma

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Because of the possibility of initiating Because of the possibility of initiating atrial atrial fibrillation fibrillation with rapid ventricular rates in a with rapid ventricular rates in a patient with WPW, patient with WPW, a defibrillatora defibrillator should be should be available when adenosine is administered to any available when adenosine is administered to any patient in whom WPW is a consideration.patient in whom WPW is a consideration.

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If adenosine or vagal maneuvers disclose If adenosine or vagal maneuvers disclose another form of SVT (such as atrial another form of SVT (such as atrial fibrillation or flutter), treatment with a fibrillation or flutter), treatment with a longer-acting AV nodal blocking agent longer-acting AV nodal blocking agent should be consideredshould be considered

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Calcium Channel Blockers and -Calcium Channel Blockers and -BlockersBlockers

If adenosine and If adenosine and vagal maneuvers fail to vagal maneuvers fail to convert PSVTconvert PSVT

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VerapamilVerapamil

2.5 mg to 5 mg2.5 mg to 5 mg IV bolus over 2 minutes IV bolus over 2 minutes (over 3 minutes in older patients). (over 3 minutes in older patients).

If there is no therapeutic response and no If there is no therapeutic response and no drug-induced adverse eventdrug-induced adverse event, repeated , repeated doses of doses of 5 mg to 10 mg5 mg to 10 mg every 15 to 30 min. every 15 to 30 min.

total dose 20 mgtotal dose 20 mg

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Verapamil Verapamil should not should not be given to patients be given to patients with:with:

wide-complex tachycardiaswide-complex tachycardias impaired ventricular function impaired ventricular function heart failureheart failure

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Diltiazem Diltiazem

give a dose of give a dose of 15 mg to 20 15 mg to 20 mg (0.25 mg (0.25 mg/kg) IV mg/kg) IV over 2 minutesover 2 minutes

if needed, in 15 minutes if needed, in 15 minutes give an additional IV dose of 20 mg to 25 give an additional IV dose of 20 mg to 25

mg (0.35 mg/kg). mg (0.35 mg/kg). The maintenance infusion dose is 5 The maintenance infusion dose is 5

mg/hour to 15 mg/hour, titrated to heart mg/hour to 15 mg/hour, titrated to heart rate.rate.

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Beta-blockersBeta-blockers

These agents exert their effect byThese agents exert their effect by

antagonizing sympathetic tone in nodal tissueantagonizing sympathetic tone in nodal tissue,, Side effects Side effects of Beta-blockers can include of Beta-blockers can include

bradycardias, AV conduction delays, and bradycardias, AV conduction delays, and hypotension. hypotension.

beta-blockers should be used with beta-blockers should be used with cautioncaution in in patients with patients with COPDCOPD or or CHFCHF

Esmolol: 500mic/kg stat & 50mic/kg/min infusion..Esmolol: 500mic/kg stat & 50mic/kg/min infusion..

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antiarrhythmic medications (eg, antiarrhythmic medications (eg, amiodarone, procainamide, amiodarone, procainamide, or sotalol) can or sotalol) can also be used to treat SVTs,also be used to treat SVTs,

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Narrow Narrow Supraventricular tachycardiaSupraventricular tachycardia Sinus tachycardiaSinus tachycardia ReentryReentry: -Atrial: AT, AF, Af: -Atrial: AT, AF, Af

-AV node: AVNRT, AVRT(PSVT)-AV node: AVNRT, AVRT(PSVT)

Automatic tachycardiaAutomatic tachycardia::

-Junctional tachycardia-Junctional tachycardia

-MAT-MAT

-PAC-PAC

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AV Nodal Reentrant Tachycardia Circuit

F = fast AV nodal pathway

S = slow AV nodal pathway

(His Bundle)

During sinus rhythm, impulses conduct preferentiallyvia the fast pathway

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Initiation of AV Nodal Reentrant Tachycardia

PAC = premature atrial complex (beat)

PAC

PAC

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Sustainment of AV Nodal Reentrant Tachycardia

Rate 150-250beats per min

P waves generatedretrogradely(AV node atria) andfall within orat tail of QRS

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P P P P

Sustained AV Nodal Reentrant Tachycardia

Note fixed, short RP interval mimicking r’ deflection of QRS

V1

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“pseudo-R’”

Orthodromic AV Reentrant Tachycardia

AP

Anterogadeconduction via normal pathwayRetrograde

conductionvia accessorypathway (AP)

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Initiation of Orthodromic AV Reentrant Tachycardia

AVN

Ventricles

Atria

AP

PAC = premature atrial complex (beat)

PAC

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Sustainment of Orthodromic AV Reciprocating Tachycardia

Atria

AP

AVN

Ventricles

Retrograde P’s fall in the ST segmentwith fixed, short RP

Rate 150-250beats per min

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Accessory Pathway with Ventricular Preexcitation(Wolff-Parkinson-White Syndrome)

Fusion activation of the ventricles

“Delta” Wave

APPR < .12 s

QRS .12 s

Sinusbeat

Hybrid QRS shape

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Varying Degrees of Ventricular Preexcitation

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Orthodromic AV Reentrant Tachycardia

NSR with V Preex

SVT:V Preex gone

Note retrograde P wavesin the ST segment

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Type A WPWType A WPW

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Type B WPWType B WPW

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AF + WPWAF + WPW

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Pre-excitation syndromePre-excitation syndrome(W-P-W syndrome)(W-P-W syndrome)

There are several type of accessory There are several type of accessory pathwaypathway

1.1. KentKent: adjacent atrial and ventricular : adjacent atrial and ventricular

2.2. JamesJames: adjacent atrial and his : adjacent atrial and his bundlebundle

3.3. MahaimMahaim: adjacent lower part of the : adjacent lower part of the AVN and ventricularAVN and ventricular

Usually no structure heart disease, Usually no structure heart disease, occur in any age individualoccur in any age individual

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A 45 y/o male with chest painA 45 y/o male with chest painRate: 200 Rhythm: non-sinus Axis: normal Rate: 200 Rhythm: non-sinus Axis: normal Dx: PSVT-AVNRT & rate relared ischemia, Dx: PSVT-AVNRT & rate relared ischemia, Management: Adenosin or cardioversion Management: Adenosin or cardioversion

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WPW WPW

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LGL Lone-Ganong-LevinLGL Lone-Ganong-Levin

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WPWWPW

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LGL + PVC + RBBBLGL + PVC + RBBB

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Sinus TachycardiaSinus Tachycardia

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Sinus Tachycardia (100 to 180+ beats/min)

• P waves oriented normally• PR usually shorter than at rest

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Causes of Sinus TachycardiaCauses of Sinus Tachycardia

Hypovolemia ( blood loss, dehydration)Hypovolemia ( blood loss, dehydration) FeverFever Respiratory distressRespiratory distress Heart failureHeart failure HyperthyroidismHyperthyroidism Certain drugs (e.g., bronchodilators)Certain drugs (e.g., bronchodilators) Physiologic states (exercise, excitement, Physiologic states (exercise, excitement,

etc)etc)

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Atrial Tachyarrhythmias

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V5

P P P P’ P

Timing of Expected P

Premature Atrial Complex (PAC)

Non-Compensatory Pause

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• RP intervals can be variable • RP often > PR• (Example slower than more common rate 150-250 beats per min)

Multifocal Atrial Tachycardia (MAT)

V1

Differs fromAV nodal or AV reentrantSVT

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Atrial Flutter (“Typical,” Counterclockwise)

Reentrant mechanism

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II

V1

Atrial Flutter

4:1 2:1

Classicinverted “sawtooth”flutter wavesat 300/min (best seen inII, III and AVF)

Note variableventricularresponse

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Atrial Flutter

2:1Conduction(common)

2:1 & 3:2Conduction

1:1Conduction(rare but dangerous)

V. rate 140-160beats/min

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Atrial FibrillationAtrial Fibrillation

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Atrial Fibrillation

Focal firingormultiplewavelets

Chaotic, rapidatrial rate at400-600beats per min

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V5

Atrial Fibrillation

• Rapid, undulating baseline (best seen in V1)• Most impulses block in AV node Erratic conduction

V1

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Atrial Fibrillation: Characteristic “Irregularly Irregular” Ventricular Response

II

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PR=190PR=190BP=85/55BP=85/55

Her ECG Her ECG

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Typical AVNRTTypical AVNRT

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After 6 mg AdenosineAfter 6 mg Adenosine

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Responses of narrow complex Responses of narrow complex tachycardias to adenosinetachycardias to adenosine

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Next Next

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Case 2Case 2

33 year old female presents with intense 33 year old female presents with intense palpitations and chest tightnesspalpitations and chest tightness

Similar episodes several times a year for Similar episodes several times a year for the last 5 yearsthe last 5 years

Episode of syncope 3 months agoEpisode of syncope 3 months ago She is confuse, BP=85/55 PR=190,She is confuse, BP=85/55 PR=190, Has cold sweeting,Has cold sweeting,

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Dx ?Dx ? PSVT (AVRT)PSVT (AVRT)

Therapy?Therapy?

50J synch. shock50J synch. shock

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Next Next

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Case 3Case 3

72 year old presents with pneumonia72 year old presents with pneumonia Long history of smoking / COPDLong history of smoking / COPD

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What would you do next ?What would you do next ?

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Next Next

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Atrial FibrillationAtrial Fibrillation

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Atrial Fibrillation

The most common sustained arrhythmia in clinical practice

5% of people over age 70 years of age and 15% of those over age 80 years 107107

Atrial Fibrillation: Triggers

• Initiation of atrial fibrillation with a single PAC• Most of these triggers originate in the PVs

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Atrial fibrillation –Atrial fibrillation –initial assessmentinitial assessment

Onset (paroxysmal vs persistent/chronic) Onset (paroxysmal vs persistent/chronic)

SymptomsSymptoms

Haemodynamic stabilityHaemodynamic stability

Co-existing conditions ( AS ,HOCM ,CAD , CHF)Co-existing conditions ( AS ,HOCM ,CAD , CHF)

TriggersTriggers

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AF Management?AF Management?

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Rhythm controlRhythm control Synchronised DC cardioversionSynchronised DC cardioversion

Chemical cardioversionChemical cardioversion Amiodarone ( iv / po )Amiodarone ( iv / po )

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Atrial Fibrillation with Rapid Conduction Via Accessory Pathway

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Next Next

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Premature Ventricular Complex Premature Ventricular Complex (PVC):(PVC):

Alternative Terminology Alternative Terminology

Premature ventricular Premature ventricular contractioncontraction

Ventricular Ventricular extrasystoleextrasystole

Ventricular Ventricular premature beatpremature beat

Ventricular Ventricular ectopic beatectopic beat

Ventricular Ventricular premature depolarizationpremature depolarization

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Premature Ventricular Complex (PVC)

Compensatory Pause

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PVCs: Bigeminal Pattern

“Regularly Irregular” Rhythm

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Next Next

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Case 4Case 4

70 year-old-man presents to the ER with a 70 year-old-man presents to the ER with a 3 hour history of palpitations that started 3 hour history of palpitations that started suddenly while gardeningsuddenly while gardening

Similar shorter episodes for last 3 yearsSimilar shorter episodes for last 3 years 2-3 episodes /month , usually 1-2 hours2-3 episodes /month , usually 1-2 hours Associated SOB and fatigueAssociated SOB and fatigue

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What else do you want to know from the What else do you want to know from the history?history?

Differential diagnosis ?Differential diagnosis ?

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Wide-Complex TachycardiaWide-Complex Tachycardia

The first step :The first step :

stable or unstable?stable or unstable? An An unstableunstable patient with a wide-complex patient with a wide-complex

tachycardia should be presumed to have tachycardia should be presumed to have VT and VT and immediate cardioversion immediate cardioversion should be should be performedperformed

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Precordial thump Precordial thump may be considered for may be considered for patients with patients with witnessedwitnessed, monitored, , monitored, unstableunstable ventricular tachycardia if a ventricular tachycardia if a defibrillator is defibrillator is not immediately not immediately ready for ready for useuse

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If stable If stable

the second step:the second step: obtain a 12-lead ECGobtain a 12-lead ECG

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DDxDDx

● ● VT or VFVT or VF

● ● SVT with aberrancySVT with aberrancy

● ● Pre-excited tachycardias (associated with Pre-excited tachycardias (associated with or mediated by an accessory pathway)or mediated by an accessory pathway)

● ● Ventricular paced rhythmsVentricular paced rhythms

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The The third step:third step: regular or irregularregular or irregular

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Ladder Diagram of AV Dissociation During Ventricular Tachycardia

Slower atrial rate

Faster ventricular rate

Impulses invade the AV node retrogradely and anterogradely,creating physiologic “interference” and block. Under the right conditions, some anterograde impulses may slip through.

This phenomenon is not equivalent to third degree AV block

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Monomorphic VT

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V1

Polymorphic VT

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“Torsade de Pointes”(Polymorphic VT Associated with Prolonged Repolarization)

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Regular Wide QRS Tachycardia: VT or SVT with Aberrant Conduction?

V1

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Clinical Clues to Basis Clinical Clues to Basis for Regular Wide QRS Tachycardiafor Regular Wide QRS Tachycardia

REMEMBER: VT does REMEMBER: VT does notnot invariably cause invariably cause hemodynamic collapse; patients may be hemodynamic collapse; patients may be conscious and stableconscious and stable

History of heart disease, History of heart disease, especially priorespecially prior myocardial infarctionmyocardial infarction, suggests VT, suggests VT

Occurrence in a young patient with no Occurrence in a young patient with no known heart disease suggests SVTknown heart disease suggests SVT

12-lead EKG (if patient stable) should be 12-lead EKG (if patient stable) should be obtainedobtained

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Regular Wide QRS Tachycardia: VT or SVT with Aberrant Conduction?

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Artifact Mimicking “VT”

Artifact precedes“VT”

QRS complexes “march through”the pseudo-tachyarrhythmia

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Ectopic ventricular activation

Normal ventricular activation

Fusionbeat

Accelerated Idioventricular Rhythm ( Ventricular Escape Rate, but 100 bpm)

Sinus acceleration

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Case 5Case 5

68-year-old man presents with an 8-hour 68-year-old man presents with an 8-hour history of palpitations and chest tightness- history of palpitations and chest tightness- no lightheadednessno lightheadedness

Previous history of myocardial infarction 5 Previous history of myocardial infarction 5 years ago treated with angioplasty and years ago treated with angioplasty and stent – no recurrent angina sincestent – no recurrent angina since

What is the differential diagnosis?What is the differential diagnosis?

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VA dissociation on ECGVA dissociation on ECG proves VT but proves VT but is clearly discernible in only 30% - is clearly discernible in only 30% - evidence of VA dissociation on physical evidence of VA dissociation on physical examination may be usefulexamination may be useful Irregular cannon A waves in the JVPIrregular cannon A waves in the JVP Variability in loudness of S1Variability in loudness of S1

Fusion complexes / capture beatsFusion complexes / capture beats

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Differential diagnosis of wide Differential diagnosis of wide complex tachycardiacomplex tachycardia

RegularRegular SVT with bundle branch block aberrancySVT with bundle branch block aberrancy

• Pre-existingPre-existing• Rate-relatedRate-related

Antidromic AVRTAntidromic AVRT Atrial flutter / tachycardia with aberrancy or conduction over Atrial flutter / tachycardia with aberrancy or conduction over

acc.pathway (bystander)acc.pathway (bystander) VTVT

IrregularIrregular AFAF Atrial flutter / atrial tachycardia with variable conduction andAtrial flutter / atrial tachycardia with variable conduction and

• Bundle branch blockBundle branch block• Antegrade conduction via accessory pathwayAntegrade conduction via accessory pathway

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Wide complex tachycardiaWide complex tachycardia

Stable vital signs during WCT are not Stable vital signs during WCT are not useful for distinguishing SVT from VTuseful for distinguishing SVT from VT

In the event of previous MI or LV In the event of previous MI or LV dysfunction VT is dysfunction VT is by farby far more likely more likely

If in doubt , avoid iv verapamil / If in doubt , avoid iv verapamil / diltiazem - can be catastrophic in VTdiltiazem - can be catastrophic in VT

Response to adenosine is not proof Response to adenosine is not proof that the WCT was SVTthat the WCT was SVT

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CautionCaution

DO NOT use verapamil , digoxin or DO NOT use verapamil , digoxin or

b-blockers in patients with WPWb-blockers in patients with WPW

may lead to rapid ventricular response and may lead to rapid ventricular response and cause VF in case of AFcause VF in case of AF

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Irregular wide QRS tachycardia-Irregular wide QRS tachycardia-preexcited AFpreexcited AF

Approximately 30% of patients with WPW Approximately 30% of patients with WPW also have AFalso have AF

DCCV is preferredDCCV is preferred

DO NOT use AV node blocking drugsDO NOT use AV node blocking drugs

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Management of wide QRS complex Management of wide QRS complex tachycardiatachycardia

Haemodynamically unstableHaemodynamically unstable DC cardioversionDC cardioversion

Haemodynamically stableHaemodynamically stable IV amiodaroneIV amiodarone

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Case 6ECG faxed – 70-year admitted with pre-syncope

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ECG artifact mimicking VTECG artifact mimicking VT

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Artifact or VT ?Artifact or VT ?

Absence of symptoms or haemodynamic Absence of symptoms or haemodynamic deterioration during the event deterioration during the event (but can not rely on this criterion)(but can not rely on this criterion)

Normal QRS complexes within the artifactNormal QRS complexes within the artifact Unstable baseline before, after the event Unstable baseline before, after the event

or bothor both Association with body movement or Association with body movement or

intermittent skin-electrode contactintermittent skin-electrode contact

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What is the rhythm ?What is the rhythm ?

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What is the rhythm?What is the rhythm?

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Pacemaker mediated tachycardiaPacemaker mediated tachycardia

Abnormal consequence of normal pacemaker Abnormal consequence of normal pacemaker functionfunction

Retrograde conduction ->sensed and trackedRetrograde conduction ->sensed and tracked Can only happen in dual chamber devicesCan only happen in dual chamber devices

WHAT TO DO :WHAT TO DO : Application of magnetApplication of magnet to inhibit atrial sensing, to inhibit atrial sensing,

thereby breaking tachycardia loopthereby breaking tachycardia loop

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80 year old woman with recurrent 80 year old woman with recurrent syncope and pre-syncopesyncope and pre-syncope

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