Keywords: AHA Scientific Statements; CT imaging; ECG; MR imaging; acute coronary syndrome; ambulatory ECG monitoring; antiarrhythmic drug therapy; arrhythmogenic cardiomyopathy; athletes; cardiac electrophysiology; cardiac resynchronization therapy; cardiomyopathy; catheter ablation; congenital heart disease; echocardiography; electrophysiological testing; genetic arrhythmias; guidelines; heart failure; imaging; implantable and external cardioverter devices; implantable cardioverter-defibrillator; medication-induced arrhythmias; myocardial infarction; premature ventricular beats; resuscitation; sarcoidosis; specific pathology (eg, congenital heart disease, myocarditis, renal failure); stable coronary artery disease; sudden cardiac arrest; sudden cardiac death; torsades de pointes; ventricular fibrillation; ventricular tachycardia.