The purpose of this registry is to collect data on implant parameters, early, mid and long-term clinical effectiveness of Subcutaneous Implantable Cardioverter Defibrillator (S-ICD) therapies in order to better understand how to improve the clinical care of patients and effectiveness of S-ICD therapies.

ISIR is an observational, multicentric registry designed to collect implant and follow-up data of consecutive patients implanted with Subcutaneous Implantable Cardioverter Defibrillator (S-ICD).

A number of about 10 enrolling centers is estimated with an overall number of 400 patients.

A minimal follow-up of 6 months is required before analyzing clinical outcomes. The data analysis will focus on implant outcomes and early, mid and long-term effectiveness of S-ICD therapies and safety.

Inclusion Criteria:

• Age >/= 18 years
• Patients successfully implanted with S-ICD
• Patients able to provide written informed consent or have informed consent as provided by a legal representative

Patients with S-ICD implanted for primary or secondary prevention of sudden cardiac death