sudden death

ACC Ventricular Arrhythmias & Sudden Cardiac Death

Slide Deck

Based on the ACC/AHA/ESC 2006Guidelines for Management of

PatientsWith Ventricular Arrhythmias and thePrevention of Sudden Cardiac Death

February 2007

Supported by Medtronic, Inc.

Medtronic, Inc. was not involved in the development of this slide deck and in no way influenced its contents.

Miguel A. Quinones, MD, FACC

Gabriel Gregoratos, MD, FACC, FAHA

Cynthia Tracy, MD, FACC, FAHA

ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the

Prevention of Sudden Cardiac Death

Developed by:

Class I Benefit >>> Risk

Procedure/ Treatment SHOULD be performed/ administered

Class IIa Benefit >> RiskAdditional studies with focused objectives needed

IT IS REASONABLE to perform procedure/administer treatment

Class IIb Benefit ≥ RiskAdditional studies with broad objectives needed; Additional registry data would be helpful

Procedure/Treatment MAY BE CONSIDERED

Class III Risk ≥ BenefitNo additional studies needed

Procedure/Treatment should NOT be performed/administered SINCE IT IS NOT HELPFUL AND MAY BE HARMFUL

shouldis recommendedis indicatedis useful/effective/

beneficial

is reasonablecan be

useful/effective/ beneficial

is probably recommended or indicated

may/might be considered

may/might be reasonable

usefulness/effectiveness is unknown /unclear/uncertain or not well established

is not recommendedis not indicatedshould notis not

useful/effective/beneficial

may be harmful

Applying Classification of Recommendations and Level of Evidence

Level A

Multiple (3-5) population risk strata evaluated

General consistency of direction and magnitude of effect

Class I

• Recommen-dation that procedure or treatment is useful/ effective

• Sufficient evidence from multiple randomized trials or meta-analyses

Class IIa

• Recommen-dation in favor of treatment or procedure being useful/ effective

• Some conflicting evidence from multiple randomized trials or meta-analyses

Class IIb

• Recommen-dation’s usefulness/ efficacy less well established

• Greater conflicting evidence from multiple randomized trials or meta-analyses

Class III

• Recommen-dation that procedure or treatment not useful/effective and may be harmful

• Sufficient evidence from multiple randomized trials or meta-analyses


Level B

Limited (2-3) population risk strata evaluated

Class I

• Recommen-dation that procedure or treatment is useful/

effective• Limited evidence from single randomized trial or non-randomized studies

Class IIa

• Recommen-dation in favor of treatment or procedure being useful/effective

• Some conflicting evidence from single randomized trial or non-randomized studies

Class IIb


• Greater conflicting evidence from single randomized trial or non-randomized studies

Class III

• Recommen-dation that procedure or treatment not useful/effective and may be harmful

• Limited evidence from single randomized trial or non-randomized studies


Level C Very limited (1-2) population risk strata evaluated

Class I

• Recommen-dation that procedure or treatment is useful/ effective

• Only expert opinion, case studies, or standard-of-care

Class IIa

• Recommen-dation in favor of treatment or procedure being useful/effective

• Only diverging expert opinion, case studies, or standard-of-care

Class IIb


• Only diverging expert opinion, case studies, or standard-of-care

Class III

• Recommend-ation that procedure or treatment not useful/effective and may be harmful

• Only expert opinion, case studies, or standard-of-care


Evidence Review

The writing committee considered the following in preparing the recommendations:1. Therapy to be offered (ICD, AA drugs, and miscellaneous)2. Point at which therapy is offered (primary prevention for patients at

risk or secondary prevention for those patients who have already experienced an event)

3. Purpose of therapy (life preservation or symptom reduction/improved quality of life)

4. Etiology of arrhythmia substrate (CHD, cardiomyopathy, or other conditions)

5. Functional status of the patient (NYHA functional class)6. Status of left ventricular function (LVEF)7. Specific arrhythmia concerned (e.g., sustained monomorphic VT,

polymorphic VT, or ventricular fibrillation)

Epidemiology of VA & SCD

Classification of Ventricular Arrhythmia by Clinical Presentation

•Hemodynamically stable ♥ Asymptomatic ♥ Minimal symptoms, e.g., palpitations•Hemodynamically unstable

♥ Presyncope♥ Syncope♥ Sudden cardiac death♥ Sudden cardiac arrest


Classification of Ventricular Arrhythmia by Electrocardiography

•Nonsustained ventricular tachycardia (VT)♥ Monomorphic♥ Polymorphic

•Sustained VT♥ Monomorphic♥ Polymorphic

•Bundle-branch re-entrant tachycardia•Bidirectional VT•Torsades de pointes•Ventricular flutter•Ventricular fibrillation

Nonsustained Monomorphic VT

Nonsustained LV VT

Sustained Monomorphic VT72-year-old woman with CHD

Nonsustained Polymorphic VT

Sustained Polymorphic VTExercise induced in patient with no structural heart disease

Bundle Branch Reentrant VT

Ventricular FlutterSpontaneous conversion to NSR (12-lead ECG)

VF with Defibrillation (12-lead ECG)

Wide QRS Irregular Tachycardia:Atrial Fibrillation with antidromic conduction in patient

with accessory pathway – Not VT


Classification of Ventricular Arrhythmia by Disease Entity•Chronic coronary heart disease

•Heart failure•Congenital heart disease•Neurological disorders•Structurally normal hearts•Sudden infant death syndrome•Cardiomyopathies

♥ Dilated cardiomyopathy♥ Hypertrophic cardiomyopathy♥ Arrhythmogenic right ventricular (RV) cardiomyopathy

Incidence Events

0 10 20 30

Generalpopulation

High-risksubgroups

AVID, CIDS, CASH

MADIT I, MUSTT

SCD--HeFTHeFT

Any prior coronary event

EF<30% orheart failure

Cardiac arrestsurvivor

Arrhythmia risk markers, post MI

0 150,0000 300,000

MADIT II

Percent Absolute Number

Reused with permission from Myerburg RJ, Kessler KM, Castellanos A. Circulation 1992;85:12-10.


Incidence of Sudden Cardiac Death

• Ventricular fibrillation - 62.4%• Bradyarrhythmias (including advanced AV

block and asystole) - 16.5%• Torsades de pointes - 12.7%• Primary VT - 8.3%

Mechanisms of Sudden Cardiac Deathin 157 Ambulatory Patients

Mechanisms and Substrates

Bayes de Luna et al. Am Heart J 1989;117:151–9.

Clinical Presentations of Patients with VA & SCD

•Asymptomatic individuals with or without electrocardiographicabnormalities•Persons with symptoms potentially attributable to ventriculararrhythmias

♥ Palpitations♥ Dyspnea♥ Chest pain♥ Syncope and presyncope

•VT that is hemodynamically stable•VT that is not hemodynamically stable•Cardiac arrest

♥ Asystolic (sinus arrest, atrioventricular block)♥ VT♥ Ventricular fibrillation (VF)♥ Pulseless electrical activity

General Evaluation for Documented or Suspected VA

Resting Electrocardiogram

Resting 12-lead ECG is indicated in all patients who are evaluated for ventriculararrhythmias.

III IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIIaIIaIIa IIbIIbIIb IIIIIIIII


Exercise Testing

Exercise testing is recommended in adult patients with ventricular arrhythmias who have an intermediateor greater probability of having CHD by age, gender, and symptoms to provoke ischemic changes or ventricular arrhythmias.

Exercise testing, regardless of age, is useful in patients with known or suspected exercise-induced ventricular arrhythmias, including catecholaminergic VT, to provoke the arrhythmia, achieve a diagnosis, and determine the patient’s response to tachycardia.

III IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIIaIIa IIbIIa IIb IIIIIb IIIIII



Exercise Testing

Exercise testing can be useful in evaluating response to medical or ablation therapy in patients with known exercise-induced ventricular arrhythmias.

Exercise testing may be useful in patients with ventricular arrhythmias and a low probability of CHDby age, gender, and symptoms.

Exercise testing may be useful in the investigation ofisolated premature ventricular complexes (PVCs) inmiddle-aged or older patients without other evidenceof CHD.





Exercise Testing

See Table 1 in the ACC/AHA 2002 Guideline Update for Exercise Testing for contraindications.



Ambulatory Electrocardiography

Ambulatory ECG is indicated when there is a need to clarify the diagnosis by detecting arrhythmias, QT-interval changes, T-wave alternans (TWA), or ST changes to evaluate risk, or to judge therapy.

Event monitors are indicated when symptoms sporadic to establish whether or not they are causedby transient arrhythmias.

Implantable recorders are useful in patientssporadic symptoms suspected to be related to arrhythmias such as syncope when a symptom-rhythm correlation cannot be established by conventional diagnostic techniques.





Electrocardiographic Techniques and Measurements

It is reasonable to use T-wave alternans to improvethe diagnosis and risk stratification of patients with ventricular arrhythmias or who are at risk for developing life-threatening ventricular arrhythmias.

ECG techniques such as signal-averaged ECG(SAECG), heart rate variability (HRV), baroreceptor reflex sensitivity, and heart rate turbulence may be useful to improve the diagnosis and risk stratification of patients with ventricular arrhythmias or who are at risk of developing life-threatening ventriculararrhythmias.




Left Ventricular Function and Imaging

Echocardiography is recommended in patients withventricular arrhythmias who are suspected of havingstructural heart disease.

Echocardiography is recommended for the subset ofpatients at high risk for the development of seriousventricular arrhythmias or SCD, such as those withdilated, hypertrophic, or RV cardiomyopathies, AMIsurvivors, or relatives of patients with inherited disorders associated with SCD.





Exercise testing with an imaging modality―(echocardiography or nuclear perfusion [single-photon emission computed tomography (SPECT)])―is recommended to detect silent ischemia in patients with ventricular arrhythmias who have an intermediate probability of having CHD by age, symptoms, and gender and in whom ECG assessment is less reliable because of digoxin use, LVH, greater than 1-mm ST-segment depression at rest, Wolf-Parkinson-White (WPW) syndrome, or Left Bundle Branch Block (LBBB).

Pharmacological stress testing with an imaging modality (echocardiography or myocardial perfusion SPECT) is recommended to detect silent ischemia in patients with ventricular arrhythmias who have an intermediate probability of having CHDby age, symptoms, and gender and are physically unable to perform a symptom-limited exercise test.





MRI, cardiac computed tomography (CT), or radionuclide angiography can be useful in patients with ventricular arrhythmias when echocardiography does not provideaccurate assessment of left ventricular (LV) and RV function and/or evaluation of structural changes.

Coronary angiography can be useful in establishing or excluding the presence of significant obstructive CHD in patients with life-threatening ventricular arrhythmias or in survivors of SCD, who have an intermediate or greater probability of having CHD by age, symptoms, and gender.

LV imaging can be useful in patients undergoingbiventricular pacing.


III IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIIaIIaIIa IIbIIbIIb

IIIIIIIII

III IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIIaIIaIIa IIbIIbIIb

IIIIIIIII

Conditions Associated With VA That Can Be Diagnosed With Echocardiography

Disease Entity Diagnostic Accuracy

Dilated cardiomyopathyIschemic cardiomyopathyHypertension with moderate to severe LVHValvular heart diseaseArrhythmogenic right ventricular

cardiomyopathy (ARVC)Brugada syndrome

HighHighHighHigh

Moderate

Poor



Electrophysiological Testing in Patients With CHD

EP testing is recommended for diagnostic evaluationof patients with remote MI with symptoms suggestiveof ventricular tachyarrhythmias, including palpitations, presyncope, and syncope.

EP testing is recommended in patients with CHD toguide and assess the efficacy of VT ablation.

EP testing is useful in patients with CHD for the diagnostic evaluation of wide-QRS-complex tachycardiasof unclear mechanism.

EP testing is reasonable for risk stratificationin patients with remote MI, NSVT, and LVEF equal to or less than 40%.






Electrophysiological Testing in Patients With Syncope

EP testing is recommended in patients with syncopeof unknown cause with impaired LV function orstructural heart disease.

EP testing can be useful in patients with syncopewhen bradyarrhythmias or tachyarrhythmias are suspected and in whom noninvasive diagnostic studiesare not conclusive.



Antiarrhythmic Drugs

♥ Beta Blockers: Effectively suppress ventricular ectopic beats & arrhythmias; reduce incidence of SCD

♥ Amiodarone: No definite survival benefit; some studies have shown reduction in SCD in patients with LV dysfunction especially when given in conjunction with BB. Has complex drug interactions and many adverse side effects (pulmonary, hepatic, thyroid, cutaneous)

♥ Sotalol: Suppresses ventricular arrhythmias; is more pro-arrhythmic than amiodarone, no survival benefit clearly shown

♥ Conclusions: Antiarrhythmic drugs (except for BB) should not be used as primary therapy of VA and the prevention of SCD

Therapies for VA

Non-antiarrhythmic Drugs

♥ Electrolytes: magnesium and potassium administration can favorably influence the electrical substrate involved in VA; are especially useful in setting of hypomagnesemia and hypokalemia♥ ACE inhibitors, angiotensin receptor blockers and aldosterone blockers can improve the myocardial substrate through reverse remodeling and thus reduce incidence of SCD♥ Antithrombotic and antiplatelet agents: may reduce SCD by reducing coronary thrombosis♥ Statins: have been shown to reduce life-threatening VA in high-risk patients with electrical instability♥ n-3 Fatty acids: have anti-arrhythmic properties, but conflicting data exist for the prevention of SCD

Therapies for VA

0.6 0.8 1.0 1.2 1.4

MADIT-I

AVID

1.6 0.4

CABG-Patch

MADIT-II

1996

1997

1997

2002

Aborted cardiac arrest

N = 196

N = 1016

N = 900

N = 1232

0.46

0.62

1.07

0.69

Hazard ratio

ICD better

SCD-HeFT N = 1676

2005 0.77

1.8

LVEF, other features

0.35 or less, NSVT, EP positive

0.30 or less, prior MI

0.35 or less, LVD due to prior MI and NICM

0.35 or less, abnormal SAECG and scheduled for CABG

CASH*

2000

N = 191

Aborted cardiac arrest

DEFINITE2004

N = 458

0.65

0.35 or less, NICM and PVCs or NSVT

CIDS2000

N = 659

0.82

Aborted cardiac arrest or syncope

DINAMIT2004

N = 674

1.08

0.35 or less, MI within 6 to 40 days and impaired cardiac autonomic function

Trial Name, Pub Year

0.83

Therapies for VAICDs: Results from Primary and Secondary Prevention Trials

Primary Prevention of SCD (1)

Recommendations in previously published guidelines for prophylactic

ICD therapy based on LVEF are inconsistent:♥ Different LVEFs were chosen for inclusion in trials♥ Average EF in such trials was substantially lower than

the cutoff value for enrollment♥ Subgroup analyses in various trials have not been

consistent in their implications ♥ No trials contained randomized patients with

intermediate LVEF

Therapies for VA


♥ Because of these inconsistencies, the recommendations in this

guideline were constructed to apply to patients with an EF ≤ to a

range of values

♥ The next several slides compare the recommendations of

previously published guidelines with those in this one and the

reasoning behind the writing committee’s decision

Therapies for VA


LV dysfunction due to MI, LVEF ≤ 30%, NYHA class II, III

• 2005 ACC/AHA HF: Class I; LOE B• 2005 ESC HF: Class I; LOE A• 2004 ACC/AHA STEMI: Class IIa; LOE B• 2002 ACC/AHA/NASPE PM/ICD: Class IIa; LOE B• 2006 ACC/AHA/ESC VA/SCD: Class I; LOE A

Note: The VA/SCD Guideline has combined all trials that enrolled patients with LV dysfunction due to MI into one recommendation

Therapies for VA


LV dysfunction due to MI, LVEF 30-35%, NYHA class II, III

• 2005 ACC/AHA HF: Class IIa; LOE B• 2005 ESC HF: Class I; LOE A• 2004 ACC/AHA STEMI: N/A• 2002 ACC/AHA/NASPE PM/ICD: N/A• 2006 ACC/AHA/ESC VA/SCD: Class I; LOE A


Therapies for VA


LV dysfunction due to MI, LVEF 30-40%, NSVT, positive EP study

• 2005 ACC/AHA HF: N/A • 2005 ESC HF: N/A• 2004 ACC/AHA STEMI: Class I; LOE B• 2002 ACC/AHA/NASPE PM/ICD: Class IIb; LOE B• 2006 ACC/AHA/ESC VA/SCD: Class I; LOE A


Therapies for VA


LV dysfunction due to MI, LVEF ≤ 30%, NYHA class I

• 2005 ACC/AHA HF: Class IIa; LOE B• 2005 ESC HF: N/A• 2004 ACC/AHA STEMI: N/A• 2002 ACC/AHA/NASPE PM/ICD: N/A• 2006 ACC/AHA/ESC VA/SCD: Class IIa; LOE B

Note: The VA/SCD Guideline has expanded the range of LVEF ≤ 30-35% for patients with LVD due to MI and NYHA class I into one recommendation

Therapies for VA


LV dysfunction due to MI, LVEF ≤ 31-35%, NYHA class I

• 2005 ACC/AHA HF: N/A• 2005 ESC HF: N/A• 2004 ACC/AHA STEMI: N/A• 2002 ACC/AHA/NASPE PM/ICD: N/A• 2006 ACC/AHA/ESC VA/SCD: Class IIa; LOE B

Note: The VA/SCD Guideline has expanded the range of LVEF

≤ 30-35% for patients with LVD due to MI and NYHA class I into one recommendation

Therapies for VA


Nonischemic cardiomyopathy, LVEF ≤ 30%, NYHA class II, III

• 2005 ACC/AHA HF: Class I; LOE B• 2005 ESC HF: Class I; LOE A• 2004 ACC/AHA STEMI: N/A• 2002 ACC/AHA/NASPE PM/ICD:N/A• 2006 ACC/AHA/ESC VA/SCD: Class I; LOE B

Note: The VA/SCD Guideline has combined all trials of nonischemic cardiomyopathy, NYHA class II, III into one recommendation

Therapies for VA


Nonischemic cardiomyopathy, LVEF 30-35%, NYHA class II, III

• 2005 ACC/AHA HF: Class IIa; LOE B• 2005 ESC HF: Class I; LOE A• 2004 ACC/AHA STEMI: N/A• 2002 ACC/AHA/NASPE PM/ICD:N/A• 2006 ACC/AHA/ESC VA/SCD: Class I; LOE B

Note: The VA/SCD Guideline has combined all trials of nonischemic cardiomyopathy, NYHA class II, III into one recommendation

Therapies for VA


Nonischemic cardiomyopathy, LVEF ≤ 30%, NYHA class I

• 2005 ACC/AHA HF: Class IIb; LOE C• 2005 ESC HF: N/A• 2004 ACC/AHA STEMI: N/A• 2002 ACC/AHA/NASPE PM/ICD:N/A• 2006 ACC/AHA/ESC VA/SCD: Class IIb; LOE B

Note: The VA/SCD Guideline has expanded the range of LVEF to ≤ 30-35% for patients with nonischemic cardiomyopathy and NYHA class I into one recommendation

Therapies for VA


Nonischemic cardiomyopathy, LVEF ≤ 31-35%, NYHA class I

• 2005 ACC/AHA HF: N/A• 2005 ESC HF: N/A• 2004 ACC/AHA STEMI: N/A• 2002 ACC/AHA/NASPE PM/ICD: N/A• 2006 ACC/AHA/ESC VA/SCD: Class IIb; LOE B

Note: The VA/SCD Guideline has expanded the range of LVEF to ≤ 30-35% for patients with nonischemic cardiomyopathy and NYHA class I into one recommendation

Therapies for VA

Therapies for VA

Ablation

Ablation is indicated in patients who are otherwise at low riskfor SCD and have sustained predominantly monomorphic VTthat is drug resistant, who are drug intolerant, or who do notwish long-term drug therapy.

Ablation is indicated in patients with bundle-branch reentrant VT.

Ablation is indicated as adjunctive therapy in patients with an ICD who are receiving multiple shocks as a result of sustainedVT that is not manageable by reprogramming or changing drug therapy or who do not wish long-term drug therapy.

Ablation is indicated in patients with WPW syndrome resuscitated from sudden cardiac arrest due to AF and rapid conduction over the accessory pathway causing VF.





Therapies for VA

Ablation

Ablation can be useful therapy in patients who are otherwise at low risk for SCD and have symptomaticnonsustained monomorphic VT that is drug resistant, whoare drug intolerant or who do not wish long-term drug therapy.

Ablation can be useful therapy in patients who are otherwise at low risk for SCD and have frequent symptomatic predominantly monomorphic PVCs that aredrug resistant or who are drug intolerant or who do not wishlong-term drug therapy.

Ablation can be useful in symptomatic patients with WPW syndrome who have accessory pathways with refractory periods less than 240 ms in duration.




Therapies for VA

Ablation

Ablation of Purkinje fiber potentials may be consideredin patients with ventricular arrhythmia storm consistently provoked by PVCs of similar morphology.

Ablation of asymptomatic PVCs may be considered when the PVCs are very frequent to avoid or treat tachycardia-induced cardiomyopathy.

Ablation of asymptomatic relatively infrequent PVCs is not indicated.




Management of Cardiac Arrest

After establishing the presence of definite, suspected, orimpending cardiac arrest, the first priority should beactivation of a response team capable of identifying the specific mechanism and carrying out prompt intervention.

CPR should be implemented immediately after contacting aresponse team. In an out-of-hospital setting, if an AED is available, it shouldbe applied immediately and shock therapy administeredaccording to the algorithms contained in the documents onCPR developed by the AHA in association with the International Liaison Committee on Resuscitation (ILCOR) and/or the European Resuscitation Council (ERC).




Acute Management of Specific Arrhythmias



For victims with ventricular tachyarrhythmic mechanisms ofcardiac arrest, when recurrences occur after a maximally defibrillating shock (generally 360 J for monophasic defibrillators), intravenous amiodarone should be the preferredantiarrhythmic drug for attempting a stable rhythm after furtherdefibrillations.

For recurrent ventricular tachyarrhythmias or nontachyarrhythmic mechanisms of cardiac arrest, it is recommended to follow the algorithms contained in the documents on CPR developed by the AHA in association with ILCOR and/or the ERC.

Reversible causes and factors contributing to cardiac arrest should be managed during advanced life support, including management of hypoxia, electrolyte disturbances, mechanical factors, and volume depletion.





For response times greater than or equal to 5 min, abrief (less than 90 to 180 s) period of CPR isreasonable prior to attempting defibrillation.

A single precordial thump may be considered byhealth care professional providers when respondingto a witnessed cardiac arrest.




VT Associated With Low Troponin MI

Patients presenting with sustained VT in whom low-levelelevations in cardiac biomarkers of myocyte injury/necrosis are documented should be treated similarly topatients who have sustained VT and in whom nobiomarker rise is documented.



Sustained Monomorphic VT

Wide-QRS tachycardia should be presumed to be VTif the diagnosis is unclear.

Direct current cardioversion with appropriate sedationis recommended at any point in the treatmentcascade in patients with suspected sustained monomorphicVT with hemodynamic compromise.





Intravenous procainamide (or ajmaline in some European countries) is reasonable for initial treatment of patients withstable sustained monomorphic VT.

Intravenous amiodarone is reasonable in patients withsustained monomorphic VT that is hemodynamically unstable, refractory to conversion with countershock, orrecurrent despite procainamide or other agents.

Transvenous catheter pace termination can be useful to treat patients with sustained monomorphic VT that is refractory to cardioversion or is frequently recurrent despite antiarrhythmic medication.






Intravenous lidocaine might be reasonable for the initial treatment of patients with stable sustained monomorphicVT specifically associated with acute myocardial ischemia orinfarction.

Calcium channel blockers such as verapamil and diltiazemshould not be used in patients to terminate wide-QRS-complex tachycardia of unknown origin, especially in patients with a history of myocardial dysfunction.




Repetitive Monomorphic VT

Intravenous amiodarone, beta blockers, and intravenousprocainamide (or sotalol or ajmaline in Europe)can be useful for treating repetitive monomorphic VTin the context of coronary disease and idiopathicVT.



Polymorphic VT

Direct-current cardioversion with appropriate sedation asnecessary is recommended for patients with sustained polymorphic VT with hemodynamic compromise and is reasonable at any point in the treatment cascade.

Intravenous beta blockers are useful for patients with recurrent polymorphic VT, especially if ischemia is suspected or cannot be excluded.

Intravenous loading with amiodarone is useful for patients with recurrent polymorphic VT in the absence of abnormal repolarization related to congenital or acquired LQTS.





Polymorphic VT

Urgent angiography with a view to revascularization shouldbe considered for patients with polymorphic VT when myocardial ischemia cannot be excluded.

Intravenous lidocaine may be reasonable for treatment of polymorphic VT specifically associated with acute myocardial ischemia or infarction.




Torsades de Pointes

Withdrawal of any offending drugs and correction of electrolyte abnormalities are recommended in patients presenting with torsades de pointes.

Acute and long-term pacing is recommended for patients presenting with torsades de pointes due to heart block andsymptomatic bradycardia.




Torsades de Pointes

Management with intravenous magnesium sulfate is reasonable for patients who present with LQTS and few episodes of torsades de pointes. Magnesium is not likely to be effective in patients with a normal QT interval.

Acute and long-term pacing is reasonable for patients who present with recurrent pause-dependent torsades de pointes.

Beta blockade combined with pacing is reasonable acute therapy for patients who present with torsades de pointes and sinus bradycardia.

Isoproterenol is reasonable as temporary treatmentin acute patients who present with recurrent pause-dependent torsades de pointes who do not have congenital LQTS.






Torsades de Pointes

Potassium repletion to 4.5 to 5 mM/L may be consideredfor patients who present with torsades de pointes.

Intravenous lidocaine or oral mexiletine may be consideredin patients who present with LQT3 and torsades de pointes.




Incessant VT

Revascularization and beta blockade followed by intravenous antiarrythmic drugs such as procainamide or amiodarone are recommended for patients with recurrentor incessant polymorphic VT due to acute MI.

Intravenous amiodarone or procainamide followed by VTablation can be effective in the management of patients with frequently recurring or incessant monomorphic VT.




Incessant VT

Intravenous amiodarone and intravenous beta blockersseparately or together may be reasonable in patientswith VT storm.

Overdrive pacing or general anesthesia may be consideredfor patients with frequently recurring or incessant VT.

Spinal cord modulation may be considered for somepatients with frequently recurring or incessant VT.





LV Dysfunction Due to Prior MI

Aggressive attempts should be made to treat HF that may be present in some patients with LV dysfunction due to priorMI and VTs.

Aggressive attempts should be made to treat myocardial ischemia that may be present in some patients with VTs.

Coronary revascularization is indicated to reduce the risk of SCD in patients with VF when direct, clear evidence of acute MI is documented to immediately precede the onset of VF.




VA & SCD Related to Specific Pathology


If coronary revascularization cannot be carried out and there is evidence of prior MI and significant LV dysfunction, the primary therapy of patients resuscitated from VF should bethe ICD in patients who are receiving chronic optimal medical therapy and those who have reasonable expectation of survival with a good functional status for more than 1 year.

ICD therapy is recommended for primary prevention to reduce total mortality by a reduction in SCD in patients with LV dysfunction due to prior MI who are at least 40 days post-MI, have an LVEF less than or equal to 30% to 40%, are NYHA functional class II or III, are receiving chronic optimal medical therapy, and who have reasonable expectation of survival with a good functional status for more than 1 year.





The ICD is effective therapy to reduce mortality by areduction in SCD in patients with LV dysfunctiondue to prior MI who present with hemodynamicallyunstable sustained VT, are receiving chronic optimalmedical therapy, and who have reasonable expectationof survival with a good functional status for morethan 1 year.




Implantation of an ICD is reasonable in patients with LV dysfunction due to prior MI who are at least 40 days post-MI, have an LVEF of less than or equal to 30% to 35%, are NYHA functional class I on chronic optimal medical therapy, and who have reasonable expectation of survival with a good functional status for more than 1 year.

Amiodarone, often in combination with beta blockers, can beuseful for patients with LV dysfunction due to prior MI and symptoms due to VT unresponsive to beta-adrenergic– blocking agents.

Sotalol is reasonable therapy to reduce symptoms resulting from VT for patients with LV dysfunction due to prior MI unresponsive to beta-blocking agents.






Adjunctive therapies to the ICD, including catheter ablation or surgical resection, and pharmacological therapy with agents such as amiodarone or sotalol are reasonable to improve symptoms due to frequent episodes of sustained VT or VF inpatients with LV dysfunction due to prior MI.

Amiodarone is reasonable therapy to reduce symptoms due to recurrent hemodynamically stable VT for patients with LV dysfunction due to prior MI who cannot or refuse to have anICD implanted.

Implantation is reasonable for treatment of recurrent VT in patients post-MI with normal or near normal ventricular function who are receiving chronic optimal medical therapy and who have reasonable expectation of survival with a good functional status for more than 1 year.






Curative catheter ablation or amiodarone may be consideredin lieu of ICD therapy to improve symptoms in patients with LV dysfunction due to prior MI and recurrent hemodynamically stable VT whose LVEF is greater than 40%.

Amiodarone may be reasonable therapy for patients with LV dysfunction due to prior MI with an ICD indication, as definedabove, in patients who cannot or refuse to have an ICDimplanted.





Prophylactic antiarrhythmic drug therapy is not indicatedto reduce mortality in patients with asymptomaticnonsustained ventricular arrhythmias.

Class IC antiarrhythmic drugs in patients with a pasthistory of MI should not be used.




Valvular Heart Disease

Patients with valvular heart disease and ventricular arrhythmias should be evaluated and treated following current recommendations for each disorder.

The effectiveness of mitral valve repair or replacement to reduce the risk of SCD in patients with mitral valve prolapse, severe mitral regurgitation, and serious ventricular arrhythmias is not well established.




Congenital Heart Disease

ICD implantation is indicated in patients with congenital heart disease who are survivors of cardiac arrest after evaluation to define the cause of the event and exclude any reversible causes. ICD implantation is indicated in patients who are receiving chronic optimal medical therapy and who have reasonable expectation of survival with a good functional status for more than 1 year.

Patients with congenital heart disease and spontaneous sustained VT should undergo invasive hemodynamic and EP evaluation. Recommended therapy includes catheter ablationor surgical resection to eliminate VT. If that is not successful, ICD implantation is recommended.




Congenital Heart Disease

Invasive hemodynamic and EP evaluation is reasonable in patients with congenital heart disease and unexplained syncope and impaired ventricular function. In the absence ofa defined and reversible cause, ICD implantation is reasonable in patients who are receiving chronic optimal medical therapy and who have reasonable expectation of survival with a good functional status for more than 1 year.

EP testing may be considered for patients with congenital heart disease and ventricular couplets or NSVT to determine the risk of a sustained ventricular arrhythmia.

Prophylactic antiarrhythmic therapy is not indicated for asymptomatic patients with congenital heart disease and isolated PVCs.





Myocarditis, Rheumatic Disease, and Endocarditis

Temporary pacemaker insertion is indicated in patientswith symptomatic bradycardia and/or heart block during theacute phase of myocarditis.

Acute aortic regurgitation associated with VT should be treated surgically unless otherwise contraindicated.

Acute endocarditis complicated by aortic or annular abscess and AV block should be treated surgically unless otherwise contraindicated.





Myocarditis, Rheumatic Disease, and Endocarditis

ICD implantation can be beneficial in patients with life-threatening ventricular arrhythmias who are not in the acute phase of myocarditis, as indicated in the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices, who are receiving chronic optimal medical therapy, and who have reasonable expectation of survival with a good functional status for more than 1 year.

Antiarrhythmic therapy can be useful in patients with symptomatic NSVT or sustained VT during the acute phase of myocarditis.

ICD implantation is not indicated during the acute phase of myocarditis.





Infiltrative Cardiomyopathies

In addition to managing the underlying infiltrative cardiomyopathy, life-threatening arrhythmias should be treated in the same manner that such arrhythmias are treated in patients with other cardiomyopathies, including the use of ICD and pacemakers in patients who are receiving chronic optimal medical therapy and who have reasonable expectation of survival with a good functional status for morethan 1 year.



Endocrine Disorders and Diabetes

The management of ventricular arrhythmias secondary to endocrine disorders should address the electrolyte (potassium, magnesium, and calcium) imbalance and the treatment of the underlying endocrinopathy.

Persistent life-threatening ventricular arrhythmias that develop in patients with endocrine disorders should be treated in the same manner that such arrhythmias are treated in patients with other diseases, including use of ICD and pacemaker implantation as required in those who are receiving chronic optimal medical therapy and who have reasonable expectation of survival with a good functional status for more than 1 year.

Patients with diabetes with ventricular arrhythmias should generally be treated in the same manner as patients without diabetes.





End-Stage Renal Failure

The acute management of ventricular arrhythmias in end-stage renal failure should immediately address hemodynamicstatus and electrolyte (potassium, magnesium, and calcium)imbalance.

Life-threatening ventricular arrhythmias, especially in patients awaiting renal transplantation, should be treated conventionally, including the use of ICD and pacemaker as required, in patients who are receiving chronic optimal medical therapy and who have reasonable expectation of survival with a good functional status for more than 1 year.




Obesity, Dieting, and Anorexia

Life-threatening ventricular arrhythmias in patients with obesity, anorexia, or when dieting should be treated in thesame manner that such arrhythmias are treated in patients with other diseases, including ICD and pacemaker implantation as required. Patients receiving ICD implantation should be receiving chronic optimal medical therapy and have reasonable expectation of survival with a goodfunctional status for more than 1 year.

Programmed weight reduction in obesity and carefully controlled re-feeding in anorexia can effectively reduce the risk of ventricular arrhythmias and SCD.

Prolonged, unbalanced, very low calorie, semistarvation diets are not recommended; they may be harmful and provoke life-threatening ventricular arrhythmias.





Pericardial Diseases

Ventricular arrhythmias that develop in patients with pericardial disease should be treated in the same manner that such arrhythmias are treated in patients with other diseases including ICD and pacemaker implantation as required. Patients receiving ICD implantation should be receiving chronic optimal medical therapy and have reasonable expectation of survival with a good functional status for more than 1 year.



Pulmonary Arterial Hypertension

Prophylactic antiarrhythmic therapy generally is notindicated for primary prevention of SCD in patientswith pulmonary arterial hypertension (PAH) or otherpulmonary conditions.



Transient Arrhythmias of Reversible Cause

Myocardial revascularization should be performed, whenappropriate, to reduce the risk of SCD in patients experiencing cardiac arrest due to VF or polymorphic VT in the setting of acute ischemia or MI.

Unless electrolyte abnormalities are proved to be the cause, survivors of cardiac arrest due to VF or polymorphic VT in whom electrolyte abnormalities are discovered in general should be evaluated and treated in a manner similar to that of cardiac arrest without electrolyte abnormalities.




Transient Arrhythmias of Reversible Cause

Patients who experience sustained monomorphic VT in the presence of antiarrhythmic drugs or electrolyte abnormalities should be evaluated and treated in a manner similar to that of patients with VT without electrolyte abnormalities or antiarrhythmic drugs present. Antiarrhythmic drugs or electrolyte abnormalities should not be assumed to be the sole cause of sustained monomorphic VT.

Patients who experience polymorphic VT in association with prolonged QT interval due to antiarrhythmic medications or other drugs should be advised to avoid exposure to all agents associated with QT prolongation. A list of such drugs can be found on the Web sites www.qtdrugs.org and www.torsades.org.




VA Associated With Cardiomyopathies

Dilated Cardiomyopathy (Nonischemic)

EP testing is useful to diagnose bundle-branch reentrant tachycardia and to guide ablation in patients with nonischemic DCM.

EP testing is useful for diagnostic evaluation in patients with nonischemic DCM with sustained palpitations, wide-QRS-complex tachycardia, presyncope, or syncope.




An ICD should be implanted in patients with nonischemic DCM and significant LV dysfunction who have sustained VT or VF, are receiving chronic optimal medical therapy, and who have reasonable expectation of survival with a good functional status for more than 1 year.

ICD therapy is recommended for primary prevention toreduce total mortality by a reduction in SCD in patients withnonischemic DCM who have an LVEF less than or equal to 30% to 35%, are NYHA functional class II or III, who are receiving chronic optimal medical therapy, and who have reasonable expectation of survival with a good functional status for more than 1 year.





ICD implantation can be beneficial for patients with unexplained syncope, significant LV dysfunction, and nonischemic DCM who are receiving chronic optimal medicaltherapy and who have reasonable expectation of survival with a good functional status for more than 1 year.

ICD implantation can be effective for termination of sustained VT in patients with normal or near normal ventricular function and nonischemic DCM who are receivingchronic optimal medical therapy and who have reasonable expectation of survival with a good functional status for morethan 1 year.





Amiodarone may be considered for sustained VT or VF inpatients with nonischemic DCM.

Placement of an ICD might be considered in patients whohave nonischemic DCM, LVEF of less than or equal to 30% to 35%, who are NYHA functional class I receiving chronicoptimal medical therapy, and who have reasonableexpectation of survival with a good functional status for more than 1 year.




Hypertrophic Cardiomyopathy (HCM)

ICD therapy should be used for treatment in patients withHCM who have sustained VT and/or VF and who arereceiving chronic optimal medical therapy and who havereasonable expectation of survival with a good functionalstatus for more than 1 year.

ICD implantation can be effective for primary prophylaxisagainst SCD in patients with HCM who have 1 or more major risk factor for SCD and who are receiving chronic optimal medical therapy and in patients who have reasonable expectation of survival with a goodfunctional status for more than 1 year.

Amiodarone therapy can be effective for treatmentin patients with HCM with a history of sustained VT and/or VF when an ICD is not feasible.





Hypertrophic Cardiomyopathy

EP testing may be considered for risk assessment for SCD in patients with HCM.

Amiodarone may be considered for primary prophylaxisagainst SCD in patients with HCM who have 1 or more major risk factor for SCD if ICD implantation is notfeasible.




Risk Factors for Sudden Cardiac Death in Hypertrophic Cardiomyopathy

Major Risk Factors Possible in Individual Patients

Cardiac arrest (VF)Spontaneous sustained VTFamily history of premature sudden deathUnexplained syncopeLV thickness greater than or equal to 30 minAbnormal exercise BPNonsustained spontaneous VT

AFMyocardial ischemiaLV outflow obstructionHigh-risk mutationIntense (competitive) physical exertion

Modified with permission from Maron BJ et al. J Am Coll Cardiol 2003;42:1687-713.


Arrhythmogenic Right Ventricular Cardiomyopathy

ICD implantation is recommended for the prevention of SCDin patients with ARVC with documented sustained VT or VFwho are receiving chronic optimal medical therapy and whohave reasonable expectation of survival with a goodfunctional status for more than 1 year.

ICD implantation can be effective for the prevention of SCD in patients with ARVC with extensive disease, including thosewith LV involvement, 1 or more affected family member withSCD, or undiagnosed syncope when VT or VF has not been excluded as the cause of syncope, who are receiving chronic optimal medical therapy, and who have reasonable expectation of survival with a good functional status for more than 1 year.




Arrhythmogenic Right Ventricular Cardiomyopathy

Amiodarone or sotalol can be effective for treatment ofsustained VT or VF in patients with ARVC when ICDimplantation is not feasible.

Ablation can be useful as adjunctive therapy in managementof patients with ARVC with recurrent VT, despite optimal antiarrhythmic drug therapy.

EP testing might be useful for risk assessment ofSCD in patients with ARVC.





Arrhythmogenic RV Cardiomyopathy(RV conduction delay, inverted T-waves V1-V5)

Arrhythmogenic RV Cardiomyopathy12-lead ECG showing Epsilon wave

Sustained Monomorphic VT 49-year-old man with ARVC

Neuromuscular Disorders

Patients with neuromuscular disorders who have ventriculararrhythmias should generally be treated in the same manner as patients without neuromuscular disorders.

Permanent pacemaker insertion may be considered for neuromuscular diseases such as myotonic muscular dystrophy, Kearns-Sayre syndrome, Erb dystrophy, and peroneal muscular atrophy with any degree of AV block (including first-degree AV block) with or without symptoms, because there may be unpredictable progression of AV conduction disease.





Inheritance HB VA CM

Muscular dystrophies

Duchenne X-linked + + +++

Becker X-linked + + +++

X-linked dilated CM X-linked -- + +++

Limb-girdle 1B AD +++

+++

++

Limb-girdle 2C-2F AR + + +++

Myotonic MD AD +++

+++

+

Emery-Dreifus MD and associated disorders

X-linked, AD, AR

+++

+++

++

Other conditions

Friedich’s ataxia AR -- + +++

Kearns-Sayre syndrome -- +++

++ +

Frequency of Events in Neuromuscular Disorders Associated With Heart Disease

Note: + to +++ represents a comparison between the various medical conditions and the relative frequency of an event.

Heart Failure

ICD therapy is recommended for secondary preventionof SCD in patients who survived VF or hemodynamicallyunstable VT, or VT with syncope and who have an LVEF lessthan or equal to 40%, who are receiving chronic optimal medical therapy, and who have a reasonable expectation ofsurvival with a good functional status for more than 1 year.

ICD therapy is recommended for primary prevention toreduce total mortality by a reduction in SCD in patients withLV dysfunction due to prior MI who are at least 40 days post-MI, have an LVEF less than or equal to 30% to 40%, are NYHA functional class II or III receiving chronic optimal medical therapy, and who have reasonable expectation of survival with a good functional status for more than 1 year.



Heart Failure

ICD therapy is recommended for primary prevention to reduce total mortality by a reduction in SCD in patients with nonischemic heart disease who have an LVEF less than or equal to 30% to 35%, are NYHA functional class II or III, are receiving chronic optimal medical therapy, and who have reasonable expectation of survival with a good functional status for more than 1 year.

Amiodarone, sotalol, and/or other beta blockers are recommended pharmacological adjuncts to ICD therapy to suppress symptomatic ventricular tachyarrhythmias (both sustained and non-sustained) in otherwise optimally treated patients with HF.

Amiodarone is indicated for the suppression of acute hemodynamically compromising ventricular or supraventricular tachyarrhythmias when cardioversionand/or correction of reversible causes have failed to terminate the arrhythmia or prevent its early recurrence.




Heart Failure

ICD therapy combined with biventricular pacing can beeffective for primary prevention to reduce total mortality by areduction in SCD in patients with NYHA functional class III orIV, are receiving optimal medical therapy, in sinus rhythm with a QRS complex of at least 120 ms, and who havereasonable expectation of survival with a good functionalstatus for more than 1 year.

ICD therapy is reasonable for primary prevention to reduce total mortality by a reduction in SCD in patients with LVdysfunction due to prior MI who are at least 40 days post-MI,have an LVEF of less than or equal to 30% to 35%, are NYHAfunctional class I, are receiving chronic optimal medical therapy, and have reasonable expectation of survival with a good functional status for more than 1 year.



Heart Failure

ICD therapy is reasonable in patients who haverecurrent stable VT, a normal or near normal LVEF,and optimally treated HF and who have a reasonableexpectation of survival with a good functional statusfor more than 1 year.

Biventricular pacing in the absence of ICD therapy isreasonable for the prevention of SCD in patientswith NYHA functional class III or IV HF, an LVEFless than or equal to 35%, and a QRS complex equalto or wider than 160 ms (or at least 120 ms in thepresence of other evidence of ventricular dyssynchrony)who are receiving chronic optimal medicaltherapy and who have reasonable expectation of survival with a good functional status for more than 1 year.



Heart Failure

Amiodarone, sotalol, and/or beta blockers may be considered as pharmacological alternatives to ICD therapy to suppress symptomatic ventricular tachyarrhythmias (bothsustained and nonsustained) in optimally treated patients with HF for whom ICD therapy is not feasible.

ICD therapy may be considered for primary prevention toreduce total mortality by a reduction in SCD in patients withnonischemic heart disease who have an LVEF of less than orequal to 30% to 35%, are NYHA functional class I receiving chronic optimal medical therapy, and who have a reasonableexpectation of survival with a good functional status for more than 1 year.



Genetic Arrhythmia Syndromes

Long QT Syndrome

Lifestyle modification is recommended for patients with anLQTS diagnosis (clinical and/or molecular).

Beta blockers are recommended for patients with an LQTS clinical diagnosis (i.e., in the presence of prolonged QTinterval).

Implantation of an ICD along with use of beta blockers is recommended for LQTS patients with previous cardiac arrestand who have reasonable expectation of survival with a good functional status for more than 1 year.





Long QT Syndrome

Beta blockers can be effective to reduce SCD in patients with a molecular LQTS analysis and normal QT interval.

Implantation of an ICD with continued use of beta blockerscan be effective to reduce SCD in LQTS patients experiencing syncope and/or VT while receiving beta blockers andwho have reasonable expectation of survival with a good functionalstatus for more than 1 year.

Left cardiac sympathetic neural denervation may be considered forLQTS patients with syncope, torsades de pointes, or cardiac arrest while receiving beta blockers.

Implantation of an ICD with the use of beta blockers may be considered for prophylaxis of SCD for patients in categories possibly associated with higher risk of cardiac arrest such as LQT2 and LQT3 and who have reasonable expectation of survival with a good functional status for more than 1 year.





Long QT Syndrome in a 16-year-old girl QT=520 ms; Atrial Tachycardia with 2:1 AV conduction

Torsades de Pointes Spontaneous conversion to NSR

(continuous lead II monitor strip)


Variant

Gene Chromosome

Function

LQT1 KCNQ1 11p15.5 IKs alpha subunit

LQT2 KCNH2 7q35-35 IKr alpha subunit

LQT3 SCN5A 3p21-23 INa alpha subunit

LQT4 ANK2 4q25-2 Targeting protein

LQT5 KCNE1 21p22.1-22-2

IKs beta subunit

LQT6 KCNE2 21p22.1-22-2

IKr beta subunit

LQT7 KCNJ2 17p23.1-24.2

IK1

LQT8 CACNA1C

12p13.3 ICa alpha subunit

JLN1 KCNQ1 11p15.5 IKs alpha subunit

JLN2 KCNE1 21p22.1-22-2

IKr beta subunit

Long QT Syndrome Subtypes


Genetic Variants of Short QT Syndrome

Locus Name

Chromosomal Locus

Inheritance

Gene Symbol

Protein Reference

SQTS1

7q3p2135-q36

Autosomal dominant

KCNH2 IKr potassium channel alpha subunit (HERG)

Brugada et al.

SQTS2

11p15.5 Autosomal dominant

KCNQ1 IKs potassium channel alpha subunit (KvLQT1)

Bellocq et al.

SQTS3

17q23.1-q24.2

Autosomal dominant

KCNJ2 IK1 potassium channel (Kir 2.1)

Priori et al.

References: Brugada et al. Circulation 2004;109:30–5; Bellocq et al. Circulation 2004;109:2394–7; Priori et al; Circ Res 2005;96:800–7.


Brugada Syndrome

An ICD is indicated for Brugada syndrome patientswith previous cardiac arrest receiving chronic optimalmedical therapy and who have reasonable expectationof survival with a good functional status for morethan 1 year.

An ICD is reasonable for Brugada syndrome patients withspontaneous ST-segment elevation in V1, V2, or V3 who have had syncope with or without mutations demonstratedin the SCN5A gene and who have reasonable expectation of survival with a good functional status for more than 1 year.

Clinical monitoring for the development of a spontaneousST-segment elevation pattern is reasonable for the management of patients with ST-segment elevation induced only with provocative pharmacological challenge with or without symptoms.





Brugada Syndrome

An ICD is reasonable for Brugada syndrome patients withdocumented VT that has not resulted in cardiac arrest and who have reasonable expectation of survival with a good functional status for more than 1 year.

Isoproterenol can be useful to treat an electrical storm in theBrugada syndrome.

EP testing may be considered for risk stratification in asymptomatic Brugada syndrome patients with spontaneousST elevation with or without a mutation in the SCN5A gene.

Quinidine might be reasonable for the treatment of electrical storm in patients with Brugada syndrome.





Brugada Syndrome(Typical ST-T abnormality V1-V2)


Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)

Beta blockers are indicated for patients who are clinicallydiagnosed with CPVT on the basis of the presence of spontaneous or documented stress-induced ventriculararrhythmias.

Implantation of an ICD with use of beta blockers is indicatedfor patients with CPVT who are survivors of cardiac arrest and who have reasonable expectation of survival with a goodfunctional status for more than 1 year.




Catecholaminergic Polymorphic Ventricular Tachycardia

Beta blockers can be effective in patients without clinicalmanifestations when the diagnosis of CPVT is established during childhood based on genetic analysis.

Implantation of an ICD with the use of beta blockers can beeffective for affected patients with CPVT with syncope and/or documented sustained VT while receiving betablockers and who have reasonable expectation of survival with a good functional status for more than 1 year.

Beta blockers may be considered for patients with CPVT whowere genetically diagnosed in adulthood and never manifested clinical symptoms of tachyarrhythmias.




Arrhythmias in Structurally Normal Hearts

Idiopathic Ventricular Tachycardia

Catheter ablation is useful in patients with structurally normal hearts with symptomatic, drug-refractory VT arisingfrom the RV or LV or in those who are drug intolerant or whodo not desire long-term drug therapy.

EP testing is reasonable for diagnostic evaluation in patientswith structurally normal hearts with palpitations or suspected outflow tract VT.



Idiopathic Ventricular Tachycardia

Drug therapy with beta blockers and/or calcium channel blockers (and/or IC agents in right ventricular outflow tract VT) can be useful in patients with structurally normal hearts with symptomatic VT arising from the RV.

ICD implantation can be effective therapy for the terminationof sustained VT in patients with normal or near normalventricular function and no structural heart disease who arereceiving chronic optimal medical therapy and who havereasonable expectation of survival for more than 1 year.




Electrolyte Disturbances

Potassium (and magnesium) salts are useful in treatingventricular arrhythmias secondary to hypokalemia (or hypomagnesmia) resulting from diuretic use in patients withstructurally normal hearts.

It is reasonable to maintain serum potassium levels above4.0 mM/L in any patient with documented life-threateningventricular arrhythmias and a structurally normal heart.

It is reasonable to maintain serum potassium levels above4.0 mM/L in patients with acute MI.

Magnesium salts can be beneficial in the management of VT secondary to digoxin toxicity in patients with structurally normal hearts.






Alcohol

Complete abstinence from alcohol is recommended in caseswhere there is a suspected correlation between alcohol intake and ventricular arrhythmias.

Persistent life-threatening ventricular arrhythmias despiteabstinence from alcohol should be treated in the samemanner that such arrhythmias are treated in patients withother diseases, including an ICD, as required, in patientsreceiving chronic optimal medical therapy and who have reasonable expectation of survival for more than 1 year.




Smoking and Lipids

Smoking should be strongly discouraged in all patients withsuspected or documented ventricular arrhythmias and/or aborted SCD.

Statin therapy is beneficial in patients with CHD to reducethe risk of vascular events, possibly ventricular arrhythmias,and SCD.

n-3 polyunsaturated fatty acid supplementation may be considered for patients with ventricular arrhythmias and underlying CHD.





VA & SCD Related to Specific Populations

Athletes

Preparticipation history and physical examination, includingfamily history of premature or SCD and specific evidence ofcardiovascular diseases such as cardiomyopathies and ionchannel abnormalities, is recommended in athletes.

Athletes presenting with rhythm disorders, structuralheart disease, or other signs or symptoms suspiciousfor cardiovascular disorders should be evaluated asany other patient but with recognition of the potentialuniqueness of their activity.

Athletes presenting with syncope should be carefully evaluated to uncover underlying cardiovascular disease or rhythm disorder.




Athletes

Athletes with serious symptoms should cease competitionwhile cardiovascular abnormalities are being fully evaluated.

Twelve-lead ECG and possibly echocardiography may beconsidered as preparticipation screening for heart disordersin athletes.




Gender and Pregnancy

Pregnant women developing hemodynamically unstableVT or VF should be electrically cardioverted or defibrillated.

In pregnant women with the LQTS who have had symptoms, it is beneficial to continue beta-blocker medicationsthroughout pregnancy and afterward, unless there are definite contraindications.




Elderly Patients

Elderly patients with ventricular arrhythmias shouldgenerally be treated in the same manner as youngerindividuals.

The dosing and titration schedule of antiarrhythmicdrugs prescribed to elderly patients should be adjustedto the altered pharmacokinetics of such patients.

Elderly patients with projected life expectancy lessthan 1 year due to major comorbidities should notreceive ICD therapy.





Pediatric Patients

An ICD should be implanted in pediatric survivors of a cardiac arrest when a thorough search for a correctable cause is negativeand the patients are receiving optimal medical therapy and have reasonable expectation of survival with a good functional status formore than 1 year.

Hemodynamic and EP evaluation should be performed in the youngpatient with symptomatic, sustained VT.

ICD therapy in conjunction with pharmacological therapy is indicated for high-risk pediatric patients with a genetic basis (ion channel defects or cardiomyopathy) for either SCD or sustainedventricular arrhythmias. The decision to implant an ICD in a childmust consider the risk of SCD associated with the disease, the potential equivalent benefit of medical therapy, as well as risk of device malfunction, infection, or lead failure and that there is reasonable expectation of survival with a good functional status for more than 1 year.





Pediatric Patients

ICD therapy is reasonable for pediatric patients withspontaneous sustained ventricular arrhythmias associatedwith impaired (LVEF of 35% or less) ventricular function whoare receiving chronic optimal medical therapy and who havereasonable expectation of survival with a good functional status for more than 1 year.

Ablation can be useful in pediatric patients with symptomaticoutflow tract or septal VT that is drug resistant, when the patient is drug intolerant or wishes not to take drugs.




Pediatric Patients

Pharmacological treatment of isolated PVCs in pediatricpatients is not recommended.

Digoxin or verapamil should not be used for treatment ofsustained tachycardia in infants when VT has not beenexcluded as a potential diagnosis.

Ablation is not indicated in young patients withasymptomatic NSVT and normal ventricular function.





Patients with ICDs

Patients with implanted ICDs should receive regular follow-up and analysis of the device status.

Implanted ICDs should be programmed to obtain optimal sensitivity and specificity.

Measures should be undertaken to minimize the risk ofinappropriate ICD therapies.

Patients with implanted ICDs who present with incessant VT should be hospitalized for management.






Patients with ICDs

Catheter ablation can be useful for patients with implantedICDs who experience incessant or frequently recurring VT.

In patients experiencing inappropriate ICD therapy, EPevaluation can be useful for diagnostic and therapeuticpurposes.




Digitalis Toxicity

An antidigitalis antibody is recommended for patients whopresent with sustained ventricular arrhythmias, advanced AVblock, and/or asystole that are considered due to digitalistoxicity.

Patients taking digitalis who present with mild cardiactoxicity (e.g., isolated ectopic beats only) can be managedeffectively with recognition, continuous monitoring of cardiacrhythm, withdrawal of digitalis, restoration of normalelectrolyte levels (including serum potassium greater than 4 mM/L), and oxygenation.

Magnesium or pacing is reasonable for patients who take digitalis and present with severe toxicity (sustained ventricular arrhythmias, advanced AV block, and/or asystole).





Digitalis Toxicity

Dialysis for the management of hyperkalemia may be considered for patients who take digitalis and present withsevere toxicity (sustained ventricular arrhythmias; advancedAV block, and/or asystole).

Management by lidocaine or phenytoin is not recommendedfor patients taking digitalis and who present with severetoxicity (sustained ventricular arrhythmias, advanced AVblock, and/or asystole).




Drug Interactions Causing Arrhythmias

Drug Interacting Drug Effect

Digoxin Some antibiotics Eliminating gut flora that metabolize digoxin

Digoxin AmiodaroneQuinidineVerapamil

Increased digoxin bioavailability, reduced biliary and renal excretion due to P-glycoprotein inhibition

CyclosporineItraconazoleErythromycin

Digoxin toxicity

Quinidine Ketoconazole Increased drug levels

Cisapride Itraconazole

Terfenadine, astemizole

Erythromycin*ClarithromycinSome calcium channel blockers*Some HIV protese inhibitors (especially ritanovir)

Increased Concentration of Arrhythmogenic Drug (1 of 2)

*These may also accumulate to toxic levels with co-administration of inhibitor drugs like ketoconazole. Data from Roden DM. Proarrhythmia. In: Kass RS, ed. Handbook of Experimental Pharmacology: vol. 171. Boston: Springer Verlag, 2006:288–304.


Beta blockers propafenone

Quinidine (even ultra-low dose)Fluoxetine

Increased beta blockadeIncreased beta blockade

Flecainide Some tricyclic antidepressants Increased adverse effects

Dofetilide VerapamilCimetidineTrimethoprimKetoconazoleMegestrol

Increased plasma dofetilde concentration

Increased Concentration of Arrhythmogenic Drug (2 of 2)


Data from Roden DM. Proarrhythmia. In: Kass RS, ed. Handbook of Experimental Pharmacology: vol. 171. Boston: Springer Verlag, 2006:288–304.


Digoxin Antacids Decreased digoxin effect due to decreased absorbtion

Rifampin Increased P-glycoprotein activity

Quinidine, mexiletine

Rifampin, barbiturates Induced drug metabolism

Decreased Concentration of Antiarrhythmic Drug


Data from Roden DM. Proarrhythmia. In: Kass RS, ed. Handbook of Experimental Pharmacology: vol. 171. Boston: Springer Verlag, 2006:288–304.


QT-prolonging antiarrhythmics

Diuretics Increased T de P risk due to diuretic-induced hypokalemia

Beta blockers Amiodarone, clonidine, digoxin, dilitiazem, verapamil

Bradycardia when used in combination

Digoxin Amiodarone, beta blockers, clonidine, dilitiazem, verapamil

Verapamil Amiodarone, beta blockers, clonidine, digoxin, dilitiazem

Diltiazem Amiodarone, beta blockers, clonidine, digoxin, verapamil

Sildenafil Nitrates Increased and persistent vasodilation; risk of myocardial ischemia

Clonidine Amiodarone, beta blockers, digoxin, dilitiazem, verapamil

Amiodarone Beta blockers, clonidine, digoxin, dilitiazem, verapamil

Synergistic Pharmalogical Activity Causing Arrhythmias


Examples of Drugs Causing Torsades de Pointes

Frequent (greater than 1%)*

•Disopyramide

•Dofetilide

•Ibutilide

•Procainamide

•Quinidine

•Sotalol

•Ajmaline

Less Frequent

•Amiodarone

•Arsenic trioxide

•Bepridil

•Cisapride

•Anti-infectives: clarithromycin, erythromycin, halofantrine; pentamidine, sparfloxacin

•Antiemetics: domperidone, droperidol

•Antipsychotics: chlorpromazine, haloperidol, mesoridazine, thioridazine, pimozide

•Opioid dependence agents: methadone

* (e.g., hospitalization for monitoring recommended during drug initiation in some circumstances)

Adapted with permission from Roden DM. N Engl J Med 2004;350:1013-22.


Risk Factors for Drug-Induced Torsades de Pointes

•Female gender •Baseline QT prolongation

•Hypokalemia •Ventricular arrhythmia

•Bradycardia •Left ventricular hypertrophy

•Recent conversion from atrial fibrillation

•Congenital long QT syndrome

•Congestive heart failure •Certain DNA polymorphisms

•Digitalis therapy •Severe hypomagnesemia

•High drug concentrations (exception: quinidine), often due to drug interactions

•Concomitant use of 2 or more drugs that prolong the QT interval

•Rapid rate of intravenous drug administration

•Combination of QT-prolonging drug with its metabolic inhibitor

Adapted with permission from Roden DM. N Engl J Med 2004;350:1013-22.


Drug-Induced Long QT Syndrome

In patients with drug-induced LQTS, removal of the offendingagent is indicated.

Management with intravenous magnesium sulfate is reasonable for patients who take QT-prolonging drugs andpresent with few episodes of torsades de pointes in whichthe QT remains long.

Atrial or ventricular pacing or isoproterenol is reasonablefor patients taking QT-prolonging drugs who present withrecurrent torsades de pointes.

Potassium ion repletion to 4.5 to 5 mM/L may bereasonable for patients who take QT-prolonging drugs and present with few episodes of torsades de pointes in whom the QT remains long.






Sodium Channel Blocker-Related Toxicity

In patients with sodium channel blocker–related toxicity, removal ofthe offending agent is indicated.

Stopping the drug, reprogramming the pacemaker or repositioningleads can be useful in patients taking sodium channel blockerswho present with elevated defibrillation thresholds or pacingrequirement.

In patients taking sodium channel blockers who present with atrialflutter with 1:1 AV conduction, withdrawal of the offending agent isreasonable. If the drug needs to be continued, additional A-V nodalblockade with diltiazem, verapamil, or beta blocker or atrial flutterablation can be effective.

Administration of a beta blocker and a sodium bolusmay be considered for patients taking sodium channelblockers if the tachycardia becomes more frequentor more difficult to cardiovert.






Syndromes of Drug-Induced Arrhythmia and Their ManagementDrugs Clinical Setting Management*

Digitalis Mild cardiac toxicity (isolated arrhythmias only)

Severe toxicity; sustained ventricular arrhythmias; advanced AV block; asystole

Anti-digitalis antibodyPacingDialysis for hyperkalemia

QT-prolonging drugs

Torsades de pointes; few episodes, QT remains long

IV magnesium sulfate (MgSO4)Replete potassium (K+) to 4.5 to 5 mEq/L

Recurrent torsades de pointes Ventricular pacingIsoproterenol

*Always includes recognition, continuous monitoring of cardiac rhythm, withdrawal of offending agents, restoration of normal electrolytes (including potassium to greater than 4 mEq/L0, and oxygenation. The order shown is not meant to represent the preferred sequence when more than one treatment is listed.


Syndromes of Drug-Induced Arrhythmia and Their ManagementDrugs Clinical Setting Management*

Sodium channel blockers

Elevated defibrillation or pacing requirement

Stop drug; reposition leads

Atrial flutter with 1:1 AV conduction Diltiazem, verapamil, beta blocker (IV)

Ventricular tachycardia (more frequent; difficult to cardiovert)

Beta blocker; sodium

Brugada syndrome Stop drug; treat arrhythmia

*Always includes recognition, continuous monitoring of cardiac rhythm, withdrawal of offending agents, restoration of normal electrolytes (including potassium to greater than 4 mEq/L0, and oxygenation. The order shown is not meant to represent the preferred sequence when more than one treatment is listed.


Other Drug-Induced Toxicity

High intermittent doses and cumulative doses exceedingthe recommended levels should be avoided in patientsreceiving anthracyclines such as doxorubicin.

All patients receiving 5-fluorouracil therapy should receiveclose supervision and immediate discontinuation of theinfusion if symptoms or signs of myocardial ischemiaoccur. Further treatment with 5-fluorouracil must beavoided in these individuals.

Patients with known cardiac disease should have a fullcardiac assessment including echocardiography, whichshould be undertaken prior to use of anthracyclines such as doxorubicin, and regular long-term follow-up should be considered.





sudden death

Health & Medicine

risk procedure treatment

care class iia recommendation

case studies

multiple randomized

favor of treatment

single randomized trial

nonsustained monomorphic

nonsustained polymorphic