Sandbox: Ventricular Arrhythmias ACC -2017

Template:Ventricular Arrhythmias ACC -2017 Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1],Associate Editor(s)-in-Chief: Arzu Kalayci, M.D. [2]

2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death

History and Physical Examination

Class I

"1. Patients presenting with syncope for which VA is documented, or thought to be a likely cause, should be hospitalized for evaluation, monitoring, and management. (Level of Evidence: B-NR) "

12-lead ECG and Exercise Testing

Class I

"1. In patients with sustained, hemodynamically stable, wide complex tachycardia, a 12-lead ECG during tachycardia should be obtained. (Level of Evidence: B-NR) "

"2. In patients with VA symptoms associated with exertion, suspected ischemic heart disease, or catecholaminergic polymorphic ventricular tachycardia, exercise treadmill testing is useful to assess for exercise-induced VA. (Level of Evidence: B-NR) "

"3. In patients with suspected or documented VA, a 12-lead ECG should be obtained in sinus rhythm to look for evidence of heart disease. (Level of Evidence: B-NR) "

Ambulatory Electrocardiography

"1. Ambulatory electrocardiographic monitoring is useful to evaluate whether symptoms, including palpitations, presyncope, or syncope, are caused by VA. (Level of Evidence: B-NR) "

Implanted Cardiac Monitors

Class IIa

"1. In patients with sporadic symptoms (including syncope) suspected to be related to VA, implanted cardiac monitors can be useful. (Level of Evidence: B-R) "

Noninvasive Cardiac Imaging

Class I

"1. In patients with known or suspected VA that may be associated with underlying structural heart disease or a risk of SCA, echocardiography is recommended for evaluation of cardiac structure and function. (Level of Evidence: B-NR) "

Class IIa

"1. In patients presenting with VA who are suspected of having structural heart disease, cardiac magnetic resonance imaging (MRI) or computed tomography (CT) can be useful to detect and characterize underlying structural heart disease. (Level of Evidence: C-EO) "

Biomarkers

Class IIa

"1. In patients presenting with VA who are suspected of having structural heart disease, cardiac magnetic resonance imaging (MRI) or computed tomography (CT) can be useful to detect and characterize underlying structural heart disease. (Level of Evidence: B-NR) "

Genetic Considerations in Arrhythmia Syndromes

Class I

"1. In patients and family members in whom genetic testing for risk stratification for SCA or SCD is recommended, genetic counselling in beneficial. (Level of Evidence: C-EO) "

Invasive Cardiac Imaging: Cardiac Catheterization or CT Angiography

"1. In patients who have recovered from unexplained SCA, CT or invasive coronary angiography is useful to confirm the presence or absence of ischemic heart disease and guide decisions for myocardial revascularization. (Level of Evidence: C-EO) "

Electrophysiological Study for VA

Class IIa

"1. In patients with ischemic cardiomyopathy, NICM, or adult congenital heart disease who have syncope or other VA symptoms and who do not meet indications for a primary prevention ICD, an electrophysiological study can be useful for assessing the risk of sustained VT. (Level of Evidence: B-R) "

Class III - No Benefit

"1. In patients who meet criteria for ICD implantation, an electrophysiological study for the sole reason of inducing VA is not indicated for risk stratification. (Level of Evidence: B-R) "

"1. In patients who meet criteria for ICD implantation, an electrophysiological study for the sole reason of inducing VA is not indicated for risk stratification. (Level of Evidence: B-NR) "

Preventing SCD With HF Medications

Class I

"1. In patients with HFrEF (LVEF ≤40%), treatment with a beta blocker, a mineralocorticoid receptor antagonist and either an angiotensin-converting enzyme inhibitor, an angiotensin-receptor blocker, or an angiotensin receptor- neprilysin inhibitor is recommended to reduce SCD and all-cause mortality. (Level of Evidence: A) "

Surgery and Revascularization Procedures in Patients With Ischemic Heart Disease

Class I

"1. Patients with sustained VA and survivors of SCA should be evaluated for ischemic heart disease, and should be revascularized as appropriate. (Level of Evidence: B-NR) "

"1. In patients with anomalous origin of a coronary artery suspected to be the cause of SCA, repair or revascularization is recommended. (Level of Evidence: C-EO) "

Surgery for Arrhythmia Management

Class IIb

"1. In patients with monomorphic VT refractory to antiarrhythmic medications and attempts at catheter ablation, surgical ablation may be reasonable. (Level of Evidence: C-LD) "

Autonomic Modulation

Class IIa

"1. In patients with symptomatic, non–life-threatening VA, treatment with a beta blocker is reasonable. (Level of Evidence: C-LD) "

Class IIb

"1. In patients with VT/VF storm in whom a beta blocker, other antiarrhythmic medications, and catheter ablation are ineffective, not tolerated, or not possible, cardiac sympathetic denervation may be reasonable. (Level of Evidence: C-LD) "

Acute Management of Specific Ventricular Arrhythmia

Recommendations for Management of Cardiac Arrest

Class I

"1. CPR should be performed in patients in cardiac arrest. according to published basic and advanced cardiovascular life support algorithms. (Level of Evidence: A) "

"2. In patients with hemodynamically unstable VA that persist or recur after a maximal energy shock, intravenous amiodarone should be administered to attempt to achieve a stable rhythm after further defibrillation. (Level of Evidence: A) "

"3. Patients presenting with VA with hemodynamic instability should undergo direct current cardioversion. (Level of Evidence: A) "

"4. In patients with polymorphic VT or VF with ST-elevation MI, angiography with emergency revascularization is recommended. (Level of Evidence: B-NR) "

"5. Patients with a wide-QRS tachycardia should be presumed to have VT if the diagnosis is unclear. (Level of Evidence: C-EO) "

Class IIa

"1. In patients with hemodynamically stable VT, administration of intravenous procainamide can be useful to attempt to terminate VT. (Level of Evidence: A) "

"2. In patients with a witnessed cardiac arrest due to VF or polymorphic VT that is unresponsive to CPR, defibrillation, and vasopressor therapy, intravenous lidocaine can be beneficia. (Level of Evidence: B-R) "

"3. In patients with polymorphic VT due to myocardial ischemia, intravenous beta blockers can be useful. (Level of Evidence: B-R) "

"4. In patients with a recent MI who have VT/VF that repeatedly recurs despite direct current cardioversion and antiarrhythmic medications (VT/VF storm), an intravenous beta blocker can be useful. (Level of Evidence: B-NR) "

Class IIb

"1. In patients in cardiac arrest, administration of epinephrine (1 mg every 3 to 5 minutes) during CPR may be reasonable. (Level of Evidence: A) "

"2. In patients with hemodynamically stable VT, administration of intravenous amiodarone or sotalol may be considered to attempt to terminate VT. (Level of Evidence: B-R) "

Class III - No Benefit

"1. In patients with cardiac arrest,administration of high-dose epinephrine (>1mg boluses) compared with standard doses is not beneficial. (Level of Evidence: A) "

"2. In patients with cardiac arrest,administration of high-dose epinephrine (>1mg boluses) compared with standard doses is not beneficial. (Level of Evidence: A) "

Class III - Harm

"3. In patients with suspected AMI, prophylactic administration of lidocaine or high dose amiodarone for the prevention of VT is potentially harmful. (Level of Evidence: B-R) "

"4. In patients with a wide QRS complex tachycardia of unknown origin, calcium channel blockers (e.g., verapamil and diltiazem) are potentially harmful . (Level of Evidence: C-LD) "

Ongoing Management of Ventricular Arrhythmia (VA) and Sudden Cardiac Death (SCD) Risk Related to Specific Disease States

Secondary Prevention of SCD in Patients With Ischemic Heart Disease

Recommendations for Secondary Prevention of SCD in Patients With Ischemic Heart Disease

Class I

"1. In patients with ischemic heart disease, who either survive SCA due to VT/VF or experience hemodynamically unstable VT (LOE: B-R) or stable VT (LOE: B- NR) not due to reversible causes, an ICD is recommended if meaningful survival greater than 1 year is expected. (Level of Evidence: B-R / B-NR) "

"2. Value Statement: Intermediate Value (LOE: B-R) A transvenous ICD provides intermediate value in the secondary prevention of SCD particularly when the patient’s risk of death due to a VA is deemed high and the risk of nonarrhythmic death (either cardiac or noncardiac) is deemed low based on the patient’s burden of comorbidities and functional status.

Class I

"3. In patients with ischemic heart disease and unexplained syncope who have inducible sustained monomorphic VT on electrophysiological study, an ICD is recommended if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Coronary Artery Spasm

Recommendations for Patients With Coronary Artery Spasm

Class I

"1. In patients with VA due to coronary artery spasm, treatment with maximally tolerated doses of a calcium channel blocker and smoking cessation are indicated to reduce recurrent ischemia and VA. (Level of Evidence: B-NR) "

Class IIa

"1. In patients resuscitated from SCA due to coronary artery spasm in whom medical therapy is ineffective or not tolerated, an ICD is reasonable if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Class IIb

"1. In patients resuscitated from SCA due to coronary artery spasm, an ICD in addition to medical therapy may be reasonable if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Primary Prevention of SCD in Patients With Ischemic Heart Disease

Recommendations for Primary Prevention of SCD in Patients With Ischemic Heart Disease

Class I

"1. In patients with LVEF of 35% or less that is due to ischemic heart disease who are at least 40 days’ post-MI and at least 90 days postrevascularization, and with NYHA class II or III HF despite GDMT, an ICD is recommended if meaningful survival of greater than 1 year is expected. (Level of Evidence: A) "

"2. In patients with LVEF of 30% or less that is due to ischemic heart disease who are at least 40 days’ post-MI and at least 90 days postrevascularization, and with NYHA class I HF despite GDMT, an ICD is recommended if meaningful survival of greater than 1 year is expected. (Level of Evidence: A) "

"3.Value Statement: High Value (LOE: B-R) A transvenous ICD provides high value in the primary prevention of SCD particularly when the patient’s risk of death due to a VA is deemed high and the risk of nonarrhythmic death (either cardiac or noncardiac) is deemed low based on the patient’s burden of comorbidities and functional status.

Class I

"1. In patients with NSVT due to prior MI, LVEF of 40% or less and inducible sustained VT or VF at electrophysiological study, an ICD is recommended if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-R) "

Class IIa

"1. In nonhospitalized patients with NYHA class IV symptoms who are candidates for cardiac transplantation or an LVAD, an ICD is reasonable if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Class III - No Benefit

"1. An ICD is not indicated for NYHA class IV patients with medication-refractory HF who are not also candidates for cardiac transplantation, an LVAD, or a CRT defibrillator that incorporates both pacing and defibrillation capabilities. (Level of Evidence: C-EO) "

Treatment and Prevention of Recurrent VA in Patients With Ischemic Heart Disease

Recommendations for Treatment of Recurrent VA in Patients With Ischemic Heart Disease

Class I

"1. In patients with ischemic heart disease and recurrent VA, with significant symptoms or ICD shocks despite optimal device programming and ongoing treatment with a beta blocker, amiodarone or sotalol is useful to suppress recurrent VA. (Level of Evidence: B-R) "

"2. In patients with prior MI and recurrent episodes of symptomatic sustained VT, or who present with VT or VF storm and have failed or are intolerant of amiodarone (LOE: B-R) or other antiarrhythmic medications (LOE: B-NR) catheter ablation is recommended . (Level of Evidence: B-R / B-NR) "

Class IIb

"1. In patients with ischemic heart disease and ICD shocks for sustained monomorphic VT or symptomatic sustained monomorphic VT that is recurrent, or hemodynamically tolerated, catheter ablation as first-line therapy may be considered to reduce recurrent VA. (Level of Evidence: C-LD) "

Class III - Harm

"1. In patients with prior MI, class IC antiarrhythmic medications (e.g., flecainide and propafenone) should not be used. (Level of Evidence: B-R) "

"2. In patients with incessant VT or VF, an ICD should not be implanted until sufficient control of the VA is achieved to prevent repeated ICD shocks. (Level of Evidence: C-LD) "

Class III - No benefit

"3. In patients with ischemic heart disease and sustained monomorphic VT, coronary revascularization alone is an ineffective therapy to prevent recurrent VT. (Level of Evidence: C-LD) "

Nonischemic Cardiomyopathy (NICM)

Recommendations for Patients With NICM

Class I

"1. In patients with suspected NICM from myocardial infiltrative processes, cardiac MRI with late gadolinium enhancement is useful for diagnosis. (Level of Evidence: B-NR) "

Class IIa

"1. In patients with suspected NICM, cardiac MRI with late gadolinium enhancement can be useful for assessing risk of SCA/SCD. (Level of Evidence: B-NR) "

"1. In patients with NICM who develop conduction disease or LV dysfunction at less than 40 years of age, or who have a family history of NICM or SCD in a first-degree relative (<50 years of age), genetic counseling and genetic testing are reasonable to detect a heritable disease that may clarify prognosis and facilitate cascade screening of relatives. (Level of Evidence: C-EO) "

Secondary Prevention of SCD in Patients With NICM

Recommendations for Secondary Prevention of SCD in Patients With NICM

Class I

"1. In patients with NICM who either survive SCA due to VT/VF or experience hemodynamically unstable VT (LOE: B-R) or stable VT (LOE: B-NR) not due to reversible causes, an ICD is recommended if meaningful survival greater than 1 year is expected. (Level of Evidence: B-R / B-NR) "

Class IIa

"1. In patients with NICM who experience syncope presumed to be due to VA and who do not meet indications for a primary prevention ICD, an ICD or an electrophysiological study for risk stratification for SCD can be beneficial if meaningful survival greater than 1 year is expected. (Level of Evidence: B-NR) "

Class IIb

"1. In patients with NICM who survive a cardiac arrest, have sustained VT, or have symptomatic VA who are ineligible for an ICD (due to a limited life-expectancy and/or functional status or lack of access to an ICD), amiodarone may be considered for prevention of SCD. (Level of Evidence: B-R) "

Primary Prevention of SCD in Patients With NICM

Recommendations for Primary Prevention of SCD in Patients With NICM

Class I

"1. In patients with NICM, HF with NYHA class II–III symptoms and an LVEF of 35% or less, despite GDMT, an ICD is recommended if meaningful survival of greater than 1 year is expected. (Level of Evidence: A) "

Class IIa

"1. In patients with NICM due to a Lamin A/C mutation who have 2 or more risk factors (NSVT, LVEF <45%, nonmissense mutation, and male sex), an ICD can be beneficial if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Class IIb

"1. In patients with NICM, HF with NYHA class I symptoms and an LVEF of 35% or less, despite GDMT, an ICD may be considered if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-R) "

Class III - No benefit

"1. In patients with medication-refractory NYHA class IV HF who are not also candidates for cardiac transplantation, an LVAD, or a CRT defibrillator that incorporates both pacing and defibrillation capabilities, an ICD should not be implanted. (Level of Evidence: C-EO) "

Treatment of Recurrent VA in Patients With NICM

Recommendations for Treatment of Recurrent VA in Patients With NICM

Class IIa

"1. In patients with NICM and an ICD who experience spontaneous VA or recurrent appropriate shocks despite optimal device programming and treatment with a beta blocker, amiodarone or sotalol can be beneficial. (Level of Evidence: B-R) "

"2. In patients with NICM and recurrent sustained monomorphic VT who fail or are intolerant of antiarrhythmic medications, catheter ablation can be useful for reducing recurrent VT and ICD shocks. (Level of Evidence: B-NR) "

Arrhythmogenic Right Ventricular Cardiomyopathy

Recommendations for Arrhythmogenic Right Ventricular Cardiomyopathy

Class I

"1. In selected first-degree relatives of patients with arrhythmogenic right ventricular cardiomyopathy, clinical screening for the disease is recommended along with genetic counseling and genetic testing, if the proband has a disease causing mutation. (Level of Evidence: B-NR) "

"2. In patients with suspected arrhythmogenic right ventricular cardiomyopathy and VA or electrocardiographic abnormalities, cardiac MRI is useful for establishing a diagnosis and for risk stratification. (Level of Evidence: B-NR) "

"3. In patients with arrhythmogenic right ventricular cardiomyopathy and an additional marker of increased risk of SCD (resuscitated SCA, sustained VT, significant ventricular dysfunction with RVEF or LVEF ≤35%), an ICD is recommended if meaningful survival greater than 1 year is expected. (Level of Evidence: B-NR) "

"4. In patients with arrhythmogenic right ventricular cardiomyopathy and VA, a beta blocker is recommended.(Level of Evidence: B-NR) "

"4. In patients with a clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy , avoiding intensive exercise is recommended.(Level of Evidence: B-NR) "

Class IIa

"1. In patients with clinically diagnosed or suspected arrhythmogenic right ventricular cardiomyopathy , genetic counseling and genetic testing can be useful for diagnosis and for gene-specific targeted family screening. (Level of Evidence: B-NR) "

"2. In patients with arrhythmogenic right ventricular cardiomyopathy and syncope presumed due to VA, an ICD can be useful if meaningful survival greater than 1 year is expected. (Level of Evidence: B-NR) "

"3. In patients with clinical evidence of arrhythmogenic right ventricular cardiomyopathy but not VA, a beta blocker can be useful. (Level of Evidence: B-NR) "

"4. In patients with arrhythmogenic right ventricular cardiomyopathy and recurrent symptomatic sustained VT in whom a beta blocker is ineffective or not tolerated, catheter ablation with availability of a combined endocardial/epicardial approach can be beneficial . (Level of Evidence: B-NR) "

"5. Inpatientswithsuspectedarrhythmogenicrightventricularcardiomyopathy, a signal averaged ECG can be useful for diagnosis and risk stratification . (Level of Evidence: B-NR) "

Class IIb

"1. In asymptomatic patients with clinical evidence of arrhythmogenic right ventricular cardiomyopathy , an electrophysiological study may be considered for risk stratification. (Level of Evidence: B-NR) "

Hypertrophic Cardiomyopathy

Recommendations for Hypertrophic Cardiomyopathy

Class I

"1. In patients with HCM, SCD risk stratification should be performed at the time of initial evaluation and periodically thereafter. (Level of Evidence: B-NR) "

"2. In patients with HCM who have survived an SCA due to VT or VF, or have spontaneous sustained VT causing syncope or hemodynamic compromise, an ICD is recommended if meaningful survival greater than 1 year is expected. (Level of Evidence: B-NR) "

"3. In first-degree relatives of patients with HCM, an ECG and echocardiogram shouldbeperformed. (Level of Evidence: B-NR) "

"4. In first-degree relatives of patients with HCM due to a known causative mutation, genetic counseling and mutation-specific genetic testing are recommended. (Level of Evidence: B-NR) "

Class IIa

"1. In patients with clinically suspected or diagnosed HCM, genetic counseling and genetic testing are reasonable. (Level of Evidence: B-NR) "

"2. In patients with HCM and 1 or more of the following risk factors, an ICD is reasonable if meaningful survival of greater than 1 year is expected: a. Maximum LV wall thickness ≥30 mm (LOE: B-NR) b. SCD in 1 or more first-degree relatives presumably caused by HCM (LOE: C-LD) c. 1 or more episodes of unexplained syncope within the preceding 6 months (LOE: C-LD). (Level of Evidence: B-NR / C-LD) "

"3. In patients with HCM who have spontaneous NSVT (LOE: C-LD) or an abnormal blood pressure response with exercise (LOE: B-NR), who also have additional SCD risk modifiers or high risk features, an ICD is reasonable if meaningful survival greater than 1 year is expected. (Level of Evidence: B-NR / C-LD) "

Class IIb

"1. In patients with HCM who have NSVT (LOE: B-NR) or an abnormal blood pressure response with exercise (LOE: B-NR) but do not have any other SCD risk modifiers, an ICD may be considered, but its benefit is uncertain. (Level of Evidence: B-NR) "

"2. In patients with HCM and a history of sustained VT or VF, amiodarone may be considered when an ICD is not feasible or not preferred by the patient. (Level of Evidence: C-LD) "

Class III - No benefit

"1. In patients with HCM, an invasive electrophysiological study with programmed ventricular stimulation should not be performed for risk stratification. (Level of Evidence: B-NR) "

"2. In patients with an identified HCM genotype in the absence of SCD risk factors, an ICD should not be implanted. (Level of Evidence: B-NR) "

Myocarditis

Recommendations for Myocarditis

Class I

"1. In patients with life-threatening VT or VF associated with confirmed or clinically suspected myocarditis, referral to centers with mechanical hemodynamic support and advanced arrhythmia management is recommended. (Level of Evidence: C-LD) "

Class IIb

"1. In patients with giant cell myocarditis with VF or hemodynamically unstable VT treated according to GDMT, an ICD and/or an anti arrhythmic medication may be considered if meaningful survival of greater than 1 year is expected. (Level of Evidence: C-LD) "

Cardiac Sarcoidosis

Recommendations for Cardiac Sarcoidosis

Class I

"1. In patients with cardiac sarcoidosis who have sustained VT or are survivors of sudden cardiac arrest (SCA) or have an LVEF of 35% or less, an ICD is recommended, if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Class IIa

"1. In patients with cardiac sarcoidosis and LVEF greater than 35% who have syncope and/or evidence of myocardial scar by cardiac MRI or positron emission tomographic (PET) scan, and/or have an indication for permanent pacing implantation of an ICD is reasonable, provided that meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

"2. In patients with cardiac sarcoidosis and LVEF greater than 35%, it is reasonable to perform an electrophysiological study and to impant an ICD, if sustained VA is inducible, provided that meaningful survival of greater than 1 year is expected. (Level of Evidence: C-LD) "

"3. In patients with cardiac sarcoidosis who have an indication for permanent pacing, implantation of an ICD can be beneficial. (Level of Evidence: C-LD) "

"4. In patients with cardiac sarcoidosis with frequent symptomatic VA and evidence of myocardial inflammation, immunosuppression in combination with antiarrhythmic medication therapy can be useful to reduce VA burden. (Level of Evidence: C-LD) "

Heart Failure (HR)

Recommendation for Heart Failure With Reduced Ejection Fraction

Class IIa

"1. In patients with HFrEF who are awaiting heart transplant and who otherwise would not qualify for an ICD (e.g., NYHA class IV and/or use of inotropes) with a plan to discharge home, an ICD is reasonable. (Level of Evidence: B-NR) "

Left Ventricular Assist Device (LVAD)

Recommendation for Patients With an LVAD

Class IIa

"1. In patients with an LVAD and sustained VA, an ICD can be beneficial. (Level of Evidence: C-LD) "

Implantable Cardioverter Defibrillator (ICD) Use After Heart Transplantation

Recommendation for ICD Use After Heart Transplantation

Class IIb

"1. In patients with a heart transplant and severe allograft vasculopathy with LV dysfunction, an ICD may be reasonable if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Neuromuscular Disorders

Recommendations for Neuromuscular Disorders

Class I

"1. In patients with neuromuscular disorders, primary and secondary prevention ICDs are recommended for the same indications as for patients with NICM if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Class IIa

"1. In patients with Emery-Dreifuss and limb-girdle type IB muscular dystrophies with progressive cardiac involvement, an ICD is reasonable if a meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

"2. In patients with muscular dystrophy, follow-up for development of cardiac involvement is reasonable, even if the patient is asymptomatic at presentation. (Level of Evidence: B-NR) "

Class IIb

"1. In patients with myotonic dystrophy type 1 with an indication for a permanent pacemaker, an ICD may be considered to minimize the risk of SCA from VT if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Cardiac Channelopathies

Recommendations for Cardiac Channelopathies

Class I

"1. In first-degree relatives of patients who have a causative mutation for long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, short QT syndrome, or Brugada syndrome, genetic counseling and mutation-specific genetic testing are recommended. (Level of Evidence: B-NR) "

"1. In patients with a cardiac channelopathy and SCA, an ICD is recommended if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) "

Specific Cardiac Channelopathy Syndromes

Recommendations for Long QT Syndrome

Class I

"1. In patients with long QT syndrome with a resting QTc greater than 470 ms, a beta blocker is recommended. (Level of Evidence: B-NR) "

"2. In high-risk patients with symptomatic long QT syndrome in whom a beta blocker is ineffective or not tolerated, intensification of therapy with additional medications (guided by consideration of the particular long QT syndrome type), left cardiac sympathetic denervation, and/or an ICD is recommended. (Level of Evidence: B-NR) "

"3. In patients with long QT syndrome and recurrent appropriate ICD shocks despite maximum tolerated doses of a beta blocker, intensification of medical therapy with additional medications (guided by consideration of according to the particular long QT syndrome type) or left cardiac sympathetic denervation, is recommended. (Level of Evidence: B-NR) "

"1. In patients with clinically diagnosed long QT syndrome, genetic counseling and genetic testing are recommended. (Level of Evidence: B-NR) "

Class IIa

"1. In patients with suspected long QT syndrome, ambulatory electrocardiographic monitoring, recording the ECG lying and immediately on standing, and/or exercise treadmill testing can be useful for establishing a diagnosis and monitoring the response to therapy. (Level of Evidence: B-NR) "

"1. In asymptomatic patients with long QT syndrome and a resting QTc less than 470 ms, chronic therapy with a beta blocker is reasonable. (Level of Evidence: B-NR) "

Class IIb

"1. In asymptomatic patients with long QT syndrome and a resting QTc greater than 500 ms while receiving a beta blocker, intensification of therapy with medications (guided by consideration of the particular long QT syndrome type), left cardiac sympathetic denervation or an ICD may be considered. (Level of Evidence: B-NR) "

Class III - No Harm

"1. In patients with long QT syndrome, QT-prolonging medications are potentially harmful. (Level of Evidence: B-NR) "

Catecholaminergic Polymorphic Ventricular Tachycardia

Recommendations for Catecholaminergic Polymorphic Ventricular Tachycardia

Class I

"1. In patients with catecholaminergic polymorphic ventricular tachycardia, a beta blocker is recommended.(Level of Evidence: B-NR) "

"1. In patients with catecholaminergic polymorphic ventricular tachycardia and recurrent sustained VT or syncope, while receiving adequate or maximally tolerated beta blocker, treatment intensification with either combination medication therapy (e.g., beta blocker, flecainide), left cardiac sympathetic denervation,and/or an ICD is recommended.(Level of Evidence: B-NR) "

Class IIa

"1. In patients with catecholaminergic polymorphic ventricular tachycardia and with clinical VT or exertional syncope, genetic counseling and genetic testing are reasonable. (Level of Evidence: B-NR) "

Brugada Syndrome

Recommendations for Brugada Syndrome

Class I

"1. In asymptomatic patients with only inducible type 1 Brugada electrocardiographic pattern, observation without therapy is recommended.(Level of Evidence: B-NR) "

"2. In patients with Brugada syndrome with spontaneous type 1 Brugada electrocardiographic pattern and cardiac arrest, sustained VA or a recent history of syncope presumed due to VA, an ICD is recommended if a meaningful survival of greater than 1 year is expected.(Level of Evidence: B-NR) "

"3. In patients with Brugada syndrome experiencing recurrent ICD shocks for polymorphic VT, intensification of therapy with quinidine or catheter ablation is recommended.(Level of Evidence: B-NR) "

"4. In patients with spontaneous type 1 Brugada electrocardiographic pattern and symptomatic VA who either are not candidates for or decline an ICD, quinidine or catheter ablation is recommended.(Level of Evidence: B-NR) "

Class IIa

"1. In patients with suspected Brugada syndrome in the absence of a spontaneous type 1 Brugada electrocardiographic pattern, a pharmacological challenge using a sodium channel blocker can be useful for diagnosis. (Level of Evidence: B-NR) "

Class IIb

"1. In patients with asymptomatic Brugada syndrome and a spontaneous type 1 Brugada electrocardiographic pattern, an electrophysiological study with programmed ventricular stimulation using single and double extrastimuli may be considered for further risk stratification. (Level of Evidence: B-NR) "

"2. In patients with suspected or established Brugada syndrome, genetic counseling and genetic testing may be useful to facilitate cascade screening of relatives . (Level of Evidence: C-EO) "

Early Repolarization “J-wave” Syndrome

Recommendations for Early Repolarization Syndrome

Class I

"1. In asymptomatic patients with an early repolarization pattern on ECG, observation without treatment is recommended.(Level of Evidence: B-NR) "

"2. In patients with early repolarization pattern on ECG and cardiac arrest or sustained VA, an ICD is recommended.(Level of Evidence: B-NR) "

Class III - No Benefit

"1. In patients with early repolarization pattern on ECG, genetic testing is not recommended. (Level of Evidence: B-NR) "

Short QT Syndrome

Recommendations for Short QT Syndrome

Class I

"1. In asymptomatic patients with a short QTc interval, observation without treatment is recommended.(Level of Evidence: B-NR) "

"1. In patients with short QT syndrome who have a cardiac arrest or sustained VA, an ICD is recommended if meaningful survival greater than 1 year is expected.(Level of Evidence: B-NR) "

Class IIa

"1. In patients with short QT syndrome and recurrent sustained VA, treatment with quinidine can be useful. (Level of Evidence: C-LD) "

"2. In patients with short QT syndrome and VT/VF storm, isoproterenol infusion can be effective. (Level of Evidence: C-LD) "

Class IIb

"1. In patients with short QT syndrome, genetic testing may be considered to facilitate screening of first-degree relatives. (Level of Evidence: C-EO) "

Ventricular Arrhythmia in the Structurally Normal Heart

Recommendations for Ventricular Arrhythmia in the Structurally Normal Heart

Class I

"1. In patients with symptomatic PVCs in an otherwise normal heart, treatment with a beta blocker or nondihydropyradine calcium channel blocker is useful to reduce recurrent arrhythmias and improve symptoms.(Level of Evidence: B-R) "

Class IIa

"1. In patients with symptomatic VA in an otherwise normal heart, treatment with an antiarrhythmic medication is reasonable to reduce recurrent symptomatic arrhythmias and improve symptoms if beta blockers and nondihydropyradine calcium channel blockers are ineffective or not tolerated. (Level of Evidence: B-R) "

Outflow Tract and Atrioventricular Annular Ventricular Arrhythmia (VA)

Recommendations for Outflow Tract Ventricular Arrhythmia

Class I

"1. In patients with symptomatic outflow tract VA in an otherwise normal heart for whom antiarrhythmic medications are ineffective, not tolerated, or not the patient’s preference, catheter ablation is useful.(Level of Evidence: B-NR) "

"1. In patients with symptomatic outflow tract VT in an otherwise normal heart, a beta blocker or a calcium channel blocker is useful.(Level of Evidence: B-NR) "

Papillary Muscle Ventricular Arrhythmia (VA)

Recommendation for Papillary Muscle VA (PVCs and VT)

Class I

"1. In patients with symptomatic VA arising from the papillary muscles for whom antiarrhythmic medications are ineffective, not tolerated, or not the patient’s preference, catheter ablation is useful.(Level of Evidence: B-NR) "

Interfascicular Reentrant Ventricular Tachycardia (VT) (Belhassen Tachycardia)

Recommendations for Interfascicular Reentrant VT (Belhassen Tachycardia)

Class I

"1. In patients with verapamil-sensitive, idiopathic LVT related to interfascicular reentry for whom antiarrhythmic medications are ineffective, not tolerated, or not the patient’s preference, catheter ablation is useful.(Level of Evidence: B-NR) "

"2. In patients with sustained hemodynamically tolerated verapamil-sensitive, idiopathic LVT related to interfascicular reentry, intravenous verapamil is recommended for VT termination.(Level of Evidence: B-NR) "

Class IIa

"1. In patients with recurrent verapamil-sensitive idiopathic LVT, chronic therapy with oral verapamil can be useful. (Level of Evidence: C-LD) "

Idiopathic Polymorphic (Ventricular Tachycardia) VT/ Ventricular Fibrillation (VF)

Recommendations for Idiopathic Polymorphic VT/VF

Class I

"1. In young patients (<40 years of age) with unexplained SCA, unexplained near drowning, or recurrent exertional syncope, who do not have ischemic or other structural heart disease, further evaluation for genetic arrhythmia syndromes is recommended.(Level of Evidence: B-NR) "

"2. In patients resuscitated from SCA due to idiopathic polymorphic VT or VF, an ICD is recommended if meaningful survival greater than 1 year is expected.(Level of Evidence: B-NR) "

"3. For patients with recurrent episodes of idiopathic VF initiated by PVCs with a consistent QRS morphology, catheter ablation is useful.(Level of Evidence: B-NR) "

Premature Ventricular Complexes (PVC)-Induced Cardiomyopathy

Recommendations for Fremature Ventricular Complexes

Class I

"1. For patients who require arrhythmia suppression for symptoms or declining ventricular function suspected to be due to frequent PVCs (generally >15% of beats and predominately of 1 morphology) and for whom antiarrhythmic medications are ineffective, not tolerated, or not the patient’s preference, catheter ablation is useful.(Level of Evidence: B-NR) "

Class IIa

"1. In patients with PVC-induced cardiomyopathy, pharmacological treatment (e.g., beta blocker, amiodarone) is reasonable to reduce recurrent arrhythmias and improve symptoms and LV function. (Level of Evidence: B-NR) "

Pregnancy

Recommendations for Pregnancy

Class I

"1. In mothers with long QT syndrome, a beta blocker should be continued during pregnancy and throughout the postpartum period including in women who are breastfeeding.(Level of Evidence: B-NR) "

"1. In the pregnant patient with sustained VA, electrical cardioversion is safe and effective and should be used with standard electrode configuration.(Level of Evidence: C-EO) "

Class IIa

"1. In pregnant patients needing an ICD or VT ablation, it is reasonable to undergo these procedures during pregnancy, preferably after the first trimester.(Level of Evidence: B-NR) "

Older Patients With Comorbidities

Recommendations for Older Patients With Comorbidities

Class IIa

"1. For older patients and those with significant comorbidities, who meet indications for a primary prevention ICD, an ICD is reasonable if meaningful survival of greater than 1 year is expected.(Level of Evidence: B-NR) "