The purpose of the study is to assess the incidence of inappropriate shocks at 2 years, in a population of patients undergoing a generator replacement (VR/DR/CRT) or upgrade from a previously implanted ICD (VR/DR)

All subjects will be included during an inclusion visit (within 7 days post generator replacement or upgrade), and followed up at a post replacement visit (1 - 6 months post replacement or upgrade), at 12, 18 and 24 months post replacement or upgrade. These follow-up visits will be performed in-clinic except for the 18 months post replacement or upgrade visit, which could be performed through device remote monitoring.

Additional follow-ups can be performed at physician's discretion. Data on reportable adverse events will be collected throughout the study. All study data will be collected using an EDC system.

All delivered anti-tachycardia therapies (shock or ATP) will be reviewed by an independent board of experts in order to evaluate appropriateness.

The programming of the device parameters is at physician's discretion (suggested settings is slow VT monitoring zone 150 - 185 bpm with 30 cycles persistence, VT zone 185 - 230 bpm with 16 cycles persistence, remote monitoring activated).

Inclusion Criteria:

1. Any subject that had an ICD/CRT-D replacement/upgrade according to the latest relevant clinical guidelines with a MicroPort CRM ICD / CRT-D for less than 7 days
2. Signed and dated the informed consent form

Exclusion Criteria:

1. RV lead replacement
2. Previous ICD/CRT-D inactivated or already explanted
3. Active myocarditis
4. Primary prevention for Arrhythmogenic Ventricular Cardiomyopathy, Ion channelopathies, Hypertrophic Cardiomyopathy and Infiltrative or Inherited Cardiomyopathy.
5. Heart transplant (done or on waiting list) or implanted with a ventricular assist device (VAD)
6. Already included in an Interventional study that could confound the results of this study
7. Inability to understand the purpose of the study or to meet follow-up visits as defined in the investigational plan
8. Minor age (<18 years) or under guardianship or kept in detention
9. Ongoing drug or alcohol addiction or abuse which would interfere with the subject's ability to be compliant with the study.
10. Life expectancy less than 1 year
11. Pregnant or breast feeding

Patients indicated for an ICD or CRT-D implant according to the latest applicable guidelines and requiring a device replacement or system upgrade from a previous ICD (VR/DR/CRT-D).

A clinical study report will be completed at the end of the study and publication of study results may be performed