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Vikas Kuriachan MD FRCPC FCCS FHRS FACCCardiology/ Cardiac Electrophysiology
Clinical Associate Professor of Medicine
Director of Cardiac Implantable Electronic Device Services (Calgary)
University of Calgary
Libin Cardiovascular Institute of Alberta
March 12, 2019
Management of Ventricular Tachycardia
In Structural Heart Disease:
Reason for Hope
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DISCLOSURES• Relationships with commercial interests:
• Advisory Board:
• Medtronic
• Bayer
• Servier
• Bristol-Myers Squibb/Pfizer
• Research Support
• Medtronic
• St Jude Medical
• Speakers Bureau/Honoraria:
• Medtronic
• Johnson & Johnson / Biosense Webster
• Bayer
• Boston Scientific
• Servier
• Patents /Technology
• Apparatus for stabilizing /fixating medical device leads (provisional patent application)
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OBJECTIVES
• Identifying patients with structural heart disease who are at risk for life
threatening ventricular arrhythmias
• Understanding the role of ICD, anti-arrhythmics, and ablation in the
management of ventricular tachycardia and structural heart disease
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Monomorphic Ventricular Tachycardia (VT)
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NOT DISCUSSING
•Polymorphic VT
•Torsade de pointes
•VF
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ALSO NOT DISCUSSING…IDIOPATHIC VENTRICULAR TACHYCARDIA
• VT without structural heart disease (focal origin)
• Normal ventricles
• Same mechanism for PVCs (with or without tachycardia)
• Usually have very good prognosis
• Treatment usually for symptoms (or if cardiomyopathy)
• Beta or calcium channel blockers
• Antiarrhthmics
• Ablation
• Since almost no risk for sudden cardiac death
Gerstenfeld et al. Curr Prob Card 2013;38:131-158
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WHAT IS VT WITH STRUCTURAL HEART DISEASE?
• Common causes
• Ischemic
• Non-ischemic / Dilated
• Myocarditis
• Hypertrophic Cardiomyopathy (HCM)
• Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)
• Sarcoid
• Usually results in scar in the ventricles
• Substrate for re-entrant arrhythmias
• May result in sudden cardiac death
• Usually have ICD and optimal cardiac medications
Kuriachan et al Curr Prob Card 2015:40(40):133-200
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Exit
Slow Conduction (isthmus)
REENTRY CIRCUIT
• Reentry through an anatomic barriers
• Scar
• Valve annulus
• Zone of slow conduction
Courtesy of Drs I Kosmidou / W Stevenson
Mitral
Valve
Aortic
Valve
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• Areas of scar are often large
• Reentry circuits can be large
• Multiple potential reentry circuits
exist and different VT morphologies
can occur
• Critical part of circuit is the isthmus
Courtesy of Dr. I Kosmidou/W Stevenson
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VENTRICULAR ARRHYTHMIA LEADING TO LOSS OF ELECTRICAL ACTIVITY AND SUDDEN CARDIAC DEATH
www.uptodate.com
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1 American Heart Association. Heart Disease and Stroke Statistics –2005 Update.2 Jemel A. CA Cancer J Clin. 2003;53:5-26.
3 U.S. HIV & AIDS Statistic Summary. Avert.org
SUDDEN CARDIAC DEATHS IN THE US
Breast
Cancer2
335,000
SCD3
18,000
40,000
152,200
163,000
AIDS3
Lung
Cancer2
Stroke1
SCD claims
many lives
each year
compared to
other causes
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CASE - MR. M
• Mr M. 65 male with MI then underwent CABG. EF 20%. NYHA III
• Also:
• Permanent atrial fibrillation
• Hypertension
• Diabetes II
• Dyslipidemia
• Mild –mod renal dysfunction (GFR 50)
• He has scar in his ventricles and is at risk of sudden death
Zeitler et al JCE 2017;28(11):1345-1351
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• Patients with prior MI or LV dysfunction
• Treat reversible causes (revascularize)
• Ensure appropriate electrolyte levels
• Magnesium, Potassium
• Optimal medical therapy for underlying heart problem
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• Beta blockers
• Metoprolol, Bisoprolol, or Carvedilol
• Other cardiac medications that seem to be beneficial in reducing
sudden death
• Usually studied in patients with post-MI, coronary artery disease,
and or heart failure
• Statins
• ACE-Inhibitors
• Angiotensin receptor blockers
• Aldosterone blockers (spironolactone or eplerenone)
• Sacubitril / Valsartan (Entresto)
Mitchell LB Cardio Clin 26 (2008):405-418
McMurray et al NEJM 2014:371:993-1004
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MR M.
• Optimized on medications.
• NYHA II
• EF improved to 28% on assessment six months later.
• Hence he received a primary prevention implantable cardioverter
defibrillator (ICD)
Risk of ventricular arrhythmias 5 – 10% per year
Zeitler et al JCE 2017:28(11):1345-1351
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ICD will reduce mortality and prevent
arrhythmias?
• A) True
• B) False
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ROLE OF ICD – REACTIVENOT PREVENTATIVE
• Implantable Cardioverter Defibrillator
• Risks / benefits of procedure versus condition
• Risk of ICD Implant
• Death is < 0.1%
• Other complications range 1 – 10%
• Infection, pneumothorax, device problems, etc..
• Over a few years
• ICD usually implanted in those deemed to be high risk
for SCD
• Not always very clear
• Need extensive discussion with patient
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WHO SHOULD RECEIVE AN ICD
• Persistent Severe LV dysfunction after optimal treatment (EF < 35%)
• Primary prevention
• Most common reason today
• Prior cardiac arrest or significant, life-threatening ventricular arrhythmias
(not reversible)
• Secondary prevention
• VF in context of acute MI would be considered reversible and does not usually require
ICD
• Other risks factors/conditions
• HCM, Long QT, ARVC……
• Not just diagnosis but depends on risk of SCD
Kuriachan V et al Curr Treat Options Cardiovasc Med 2009 Feb;11(1):10-21
Life Expectancy > 1 Year
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CLINICAL TRIALS USING ICD TO DECREASE MORTALITY IN PATIENTS WITH LV DYSFUNCTION
Estes Circ 2011;124:651-656
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TRANSVENOUS ICD
kronstantinople.blogspot.com
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Boston Scientific
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EXTRAVASCULAR OR SUBSTERNAL(BEING DEVELOPED)
Startribune.com
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MR. M TWO YEARS LATER…………
Presents with symptomatic VT
episodes and ICD shocks
Baseline ECG
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STABILIZED WITH IV AMIODARONEWHAT CAN WE DO NOW?
• Treat any CHF and ischemia
• Further optimize beta-blocker
• Consider an antiarrhythmic
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Courtesy of Dr. I Kosmidou/W Stevenson
Antiarrhythmics will change the
properties of the circuit and
minimize triggers (PVCs) to
prevent VT
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ANTI-ARRHYTHMIC MEDICATIONS VAUGHAN WILLIAMS CLASSIFICATION
• Class I – Sodium channel blockers
• Flecainide, Propafenone, Lidocaine
• Class II – Beta blockers
• Class III – Potassium channel blockers
• Sotalol, Amiodarone
• Class IV – Calcium channel blockers
• Others (Digoxin)
Copyright unknown
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• Many antiarrhythmics may worsen outcomes in patients with prior MI
and LV dysfunction:
• Class I agents (Flecainide, propafenone, etc)
• Class IV agents (Diltiazem)
• No benefit for digoxin for ventricular arrhythmia prevention
• Hence the main anti-arrhythmic options in patients with VT and
structural heart disease:
• Beta-blockers
• Add Sotalol (except with renal dysfunction or severe CHF)
• Or Add Amiodarone
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TREATMENT OPTIONS
HR 0.27P<0.001
P=0.055
P=0.02
Optic Connolly et al. JAMA 2006
• Sotalol works, just not as well as amiodarone
• But much better side-effect profile
ICD shock reduction
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BACK TO MR. M
• Patient sent home on amiodarone 200 mg daily (added)
• After loading 20 grams
• Returns six months later with multiple ICD shocks for VT again
• What now?
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VANISH STUDY
VENTRICULAR TACHYCARDIA ABLATION VERSUS
ANTIARRHYTHMICS IN ISCHEMIC HEART DISEASE
• Randomized patient with prior MI and ICD who have
failed one antiarrhythmic to:
• More aggressive antiarrhythmic therapy or
ablation
Sapp et al N Engl J Med 2016; 375:111-121
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PRIMARY OUTCOME: DEATH, VT STORM, APPROPRIATE SHOCK
00.10.20.30.40.50.60.70.80.9
1
0 1 2 3 4
Pro
bab
ility
of
Even
t-fr
ee S
urv
ival
Years of Follow-up
Ablation
AADHR 0.72 (95%CI 0.53, 0.98)
P=0.037
27.9 +/- 17.1 months follow-up
Ablation reduced rate of primary endpoint by 28% in comparison to
escalating antiarrhythmics, and had better side-effect profile(Primary Endpoint combination of death, VT and ICD therapies)
Hazard ratio 0.72
P=0.04
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SUMMARY OF INDICATIONS FOR VT ABLATION
1. Patients with sustained monomorphic VT that recurs despite antiarrhythmic
drugs or when drugs are not tolerated or desired
2. Control of incessant sustained monomorphic VT or VT storm that is not due to a
transient reversible cause
3. Bundle branch re-entrant or interfascicular VT
4. Frequent PVCs, nonsustained or sustained VT in the setting of ventricular
dysfunction (and/or symptoms)
Dukkipati et al. JACC 2017:70:2924-41
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SUMMARY OF INDICATIONS FOR VT ABLATION
5. Recurrent sustained polymorphic VT and VF that is refractory to
antiarrhythmic therapy and thought to be secondary to a trigger (i.e. PVC)
that is amenable for ablation.
6. Additionally, catheter ablation can be considered for sustained
monomorphic VT despite therapy with class I/III antiarrhythmic drugs
• As an alternative to amiodarone in patients with prior MI and LVEF >30%
• And as an alternative to antiarrhythmic drugs for hemodynamically
tolerated sustained monomorphic VT due to prior MI and LVEF > 35%
Dukkipati et al. JACC 2017:70:2924-41
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ROLE OF CATHETER ABLATION IN VT WITH STRUCTURAL HEART DISEASE
Beta blockers + ICD
Add Sotalol or Amiodarone
Catheter
Ablation
Antiarrhythmics and
ablation may reduce
VT, but unclear if has
effect on mortality
Palliative vs Curative
Ongoing studies to
determine the best
course for these
patients
(i.e. VANISH 2)
VANISH
VANISH 2
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EP Lab:
Mapping of Arrhythmia and
Scar/substrate.
Then ablation.
Using:
Voltage (and geometry)
Pace Mapping
Activation Mapping
Entrainment Mapping
Substrate
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scar
Courtesy of Drs I. Kosmidou / W. Stevenson
Geometry and Voltage Map of Left Ventricle
Bipolar voltage:
Normal (purple) > 1.5mV
Border zone 0.5 – 1.5 mV
Scar (red/grey) < 0.5 mV
Can work inside the
geometry to minimize
fluoroscopy, mark relevant
features, and ablation lesions
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Nazer et al Korean Circ 2014;44(4):210-217
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GOALS OF VT ABLATION
• Ideally ablation of clinical VT (ECGs and ICD tracings)
• And any other induced VTs
• + Modification of substrate
• Regions of scar that still has electrical activity
• And plays critical role in the VT circuits
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VT ABLATION OUTCOMESIN STRUCTURAL HEART DISEASE
• Success 50 – 77 % (over 1-2 years)
• Many remain on antiarrhythmic medications
• Complications up to 7%
• Stroke/TIA, perforation, vascular injury, hemodynamic decompensation
• Death up to 3% (sick patients usually)
• May need more than one ablation
• Mortality in one year follow up to 18%
• Recurrent VT or heart failure
Dukkipati et al. JACC 2017:70:2924-41
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Nath et al. Prog in Card Dis 1995;37(4):185-204
Morady NEJM 1999;340(7):534-44
Highest
temperature
usually at 1mm
below tissue
surface
• Typical lesions (4mm electrode catheter)
• 2-3 mm depth and 5-6 mm diameter
• Larger lesions with cool-tip or larger electrode catheters (5-6mm depth)
Ablation
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WHAT IF CIRCUIT IS NOT ACCESSIBLE ENDOCARDIALLY?
• Ablation depth
• Can limit ability to reach critical
isthmus
• Epicardial or mid-myocardial
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EPICARDIAL ABLATION
• Described by Dr. Sosa (1996)
• Tuohy needle (used in epidurals)
• Advanced with minimal contrast injections
• If inadvertent RV puncture then pull back to
pericardial space
• Layering of contrast when in pericardium
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Natale JCE 2010;21:339-379
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TRANSCORONARYALCOHOL ABLATION
• Similar to HCM treatment
• Risk of heart block and deterioration of LV function
• Can be limited by lack of target vessels and collaterals
• Usually for deep septal circuits
• Cannot reach endocardially or epicardially
Brugada et al:Circ 1989; 79(3)
Sacher et al; Heart Rhythm 2008
Rarely used
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NEEDLE CATHETERABLATION
(NOT EASILY AVAILABLE)
Deeper Lesions
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FUTURE ?
• 24 Patients with VT after ablation
and anti-arrhythmics
• Stereotactic Arrhythmia
Radioablation (STAR)
Cuculich et al NEJM 2017:377:2325-36
Robinson et al. Circulation 2018
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Similar to scar homogenization in
catheter ablation
Cuculich et al NEJM 2017:377:2325-36
Robinson et al. Circulation 2018
Di Biase et al JACC 2012;60:132-41
Stereotaxis Arrhythmia
Radioablation
(STAR ablation)
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• Marked reduction in ventricular arrhythmias
• Collateral injury / side effects unknown
• Developing a research study (STAR VTM) looking at this in Calgary
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MR. M
• Went to the EP lab and had three different VTs induced
• Extensive endocardial ablation on the substrate regions of the inferior and
anterior scar
• No inducible VT at end of case.
• Stayed on same medications
• On six month follow up no further VT
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WHAT IF HE HAS MORE VT AFTER ABLATION?
• Add or increase antiarrhthmics
• Redo catheter ablation
• Not unusual to have more than one
• “Debulking”
• Same VT or new VTs
• Cardiac Transplant
• Palliation
• Other? (STAR)
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CONCLUSION
• Definitely a reason for hope in VT management in structural heart
disease
• Ongoing development of cardiac medications, ICD, and ablation
technologies