ADVANCE-D: Antitachycardia Pacing (ATP) Delivery for Painless Implantable Cardioverter Defibrillator (ICD) Therapy

Main objective: Compare \& quantify efficacy of two different sequences of burst ATP strategies for the termination of ventricular tachycardia (with Cycle Lenght (CL) of 240ms-320ms) from baseline to 12 months post randomisation in patients who are treated with ATP -8 pulses, 88% versus patients who are treated with ATP -15 pulses, 88% Secondary objectives: * Estimate the efficacy of ATP in successfully treating FVT episodes for patients in primary and secondary prevention * Estimate acceleration rate or degeneration of ATP therapy for treating spontaneous FVT episodes in the ATP 15 vs 8 arm * Compare the likelihood of syncopal events associated with spontaneous FVT episodes * Estimate the percent reduction in number of shocks delivered per patient for treating spontaneous FVT episodes * Evaluate different possible predictors of ATP success: VT rate, underlying disease, Anti-Arrhythmic Drugs (AAD), infarct zone, etc.