<prompt> Intracardiac defibrillator ICD is useful in which of the following ?Person with BrugadaPerson with Arrhythmogenic RV dysplasiaPerson after acute MI with CADAll of the above  <response>: Ref. AHA guidelines ICD Indications AHA GuidelinesClass I indications ie, the benefit greatly outweighs the risk, and the treatment should be administered are as follows:Structural heart disease, sustained VTSyncope of undetermined origin, inducible VT or VF at electrophysiologic study EPSLeft ventricular ejection fraction LVEF 35 due to prior MI, at least 40 days post-MI, NYHA class II or IIILVEF 35, NYHA class II or IIILVEF 30 due to prior MI, at least 40 days post-MILVEF 40 due to prior MI, inducible VT or VF at EPS Class IIa indications ie, the benefit outweighs the risk and it is reasonable to administer the treatment are as follows:Unexplained syncope, significant LV dysfunction, nonischemic cardiomyopathySustained VT, normal or near-normal ventricular functionHypertrophic cardiomyopathy with 1 or more major risk factorsArrhythmogenic right ventricular dysplasiacardiomyopathy ARVDC with 1 or more risk factors for sudden cardiac death SCDLong QT syndrome, syncope or VT while receiving beta-blockersNonhospitalized patients awaiting heart transplantBrugada syndrome, syncope or VTCatecholaminergic polymorphic VT, syncope or VT while receiving beta-blockersCardiac sarcoidosis, giant cell myocarditis, or Chagas disease 