Shock Efficacy Study Comparing Fixed Tilt and Fixed Pulse Width in a General Implantable-Cardioverter Population

Inclusion Criteria: * Subjects who meet the current ESC indications for ICD or CRT-D implant. This includes upgrades indications from pacemaker to ICD or to CRT-D or replacements of ICDs or CRT-Ds provided that there is no previous record of ineffective shocks * Subjects who are willing to be registered on the Merlin.net remote follow-up program * Subject ≥18 years * Subjects with life expectancy of at least 1 year * Subjects who agree to comply with the follow-up program included in this protocol Exclusion Criteria: * • Subjects on the waiting list for a heart transplant or under consideration for a transplant over the next 12 months * Subjects with Myocardial infarction or unstable angina within 40 days prior to enrollment * Subjects who have undergone a recent cardiac revascularization (PTCA, Stent or CABG) procedure in the 4 weeks prior to enrollment * Functional NYHA Class IV * Subjects who are participating in another ICD or CRT-D study * Subjects who are pregnant at the time of enrollment or women of childbearing potential that do not take contraceptives * Any disability or limitations to correctly understand or complete the study (physical, intellectual, logistical)