Ventricular tachycardia and/or fibrillation result in 200 000 - 400 000 sudden cardiac deaths each year in the US alone and atrial fibrillation currently afflicting up to 2.3 million Americans each year. Gene and cell therapies for cardiac arrhythmias are nascent fields whose raisons d’être derive from: (i) the problematic state of arrhythmia treatment today (especially atrial and ventricular tachyarrhythmias for which drugs, devices, and ablation remain more stopgap measures than optimal interventions); and, (ii) the opportunity to learn, and potentially treat and cure these arrhythmias, by exploring new technologies. Our review examines the state of antiarrhythmic therapy today and the new directions being taken...