Implantable Cardioverter-Defibrillators (ICD)

Class I (Evidence or Opinion Supports)

Hemodynamically unstable VT or VF when there is no transient or reversible cause

Hemodynamically stable sustained VT in patients with a structural heart disorder

Syncope of undetermined origin with sustained monomorphic VT induced during an electrophysiologic study

Ischemic cardiomyopathy, NYHA class II or class III heart failure symptoms during optimal medical therapy, and LV ejection fraction ≤ 0.35 measured at least 40 days post-MI and at least 90 days post-revascularization

Ischemic cardiomyopathy, NYHA class I heart failure symptoms during optimal medical therapy, and LV ejection fraction ≤ 30% measured at least 40 days post-MI and at least 90 days post-revascularization

Nonischemic dilated cardiomyopathy, NYHA class II or class III heart failure symptoms during optimal medical therapy, and LV ejection fraction ≤ 0.35

Ischemic cardiomyopathy, nonsustained VT, LV ejection fraction ≤ 40% measured at least 40 days post-MI, and inducible VF or sustained VT detected during an electrophysiologic study

Arrhythmogenic right ventricular cardiomyopathy (ARVC) with sustained VT, resuscitated cardiac arrest, or severe right or left ventricular systolic dysfunction

Long QT syndrome with documented VT or symptoms suggestive thereof while receiving beta-blocker therapy

Short QT interval with sustained VT, or cardiac arrest

Brugada syndrome with type 1 ECG pattern and syncope presumed to be due to VT

Catecholaminergic polymorphic ventricular tachycardia (CPVT) with sustained VT or syncope while receiving beta blocker therapy

Early repolarization with sustained VT or cardiac arrest

Class IIa (Evidence or Opinion In Favor)

Idiopathic dilated cardiomyopathy, significant LV dysfunction during optimal medical therapy, and unexplained syncope

Cardiomyopathy due to a lamin A/C mutation with unexplained syncope, or an independent indication for a permanent pacemaker, or ≥ 2 high-risk factors (nonsustained VT, intermediate LVEF 35% to 44%, non-missense mutation, male sex)

Hypertrophic cardiomyopathy (HCM) with ≥ 1 high risk factors other than sustained VT/VF (family history of premature sudden death, unexplained recent syncope, LV thickness ≥ 30 mm), recent syncope suspected to be arrhythmic in origin, LV apical aneurysm, or LVEF < 50%

ARVC without sustained VT/VF or severe right or left ventricular systolic dysfunction but with prior syncope or with multiple other risk factors for ventricular tachyarrhythmias (Towbin JA et al)

NYHA class IV heart failure in nonhospitalized patients awaiting cardiac transplantation

Cardiac sarcoidosis with LV ejection fraction > 35% who have ≥ 1 of the following: unexplained syncope, significant myocardial scar visible on cardiac MRI or PET scan, inducible sustained VT or VF, or an independent indication for a permanent pacemaker

Giant cell myocarditis with VF or unstable VT during optimal medical therapy

Class IIb (Less Well Supported by Evidence or Opinion)

Idiopathic dilated cardiomyopathy, NYHA class I heart failure symptoms during optimal medical therapy, LV ejection fraction ≤ 0.35

Long QT syndrome with no symptoms but a QTc > 0.50 second during beta-blocker therapy

Syncope and an advanced structural heart disorder if invasive and noninvasive investigations have not identified a cause

HCM without the risk factors listed above but with nonsustained VT or extensive late gadolinium enhancement on cardiac magnetic resonance imaging

ARVC without sustained VT/VF or severe right or left ventricular systolic dysfunction but with fewer other risk factors for ventricular tachyarrhythmias (Towbin et al)

Class III (Not Indicated or Harmful)

Syncope of unknown etiology in absence of inducible VT or VF and without a structural heart disorder

Incessant VT or VF

VT or VF with mechanisms amenable to catheter or surgical ablation

VT or VF due to transient or reversible disorders when correction is feasible and likely to prevent recurrence

Psychiatric disorders that may worsen with ICD implantation or that preclude follow-up

Patients with no reasonable expectation of survival with an acceptable functional status for ≥ 1 year

Patients with NYHA class IV medication-refractory heart failure symptoms who are not candidates for cardiac transplantation or a CRT ICD