The primary aim of the "Sensing Atrial High Rate Episodes with DX System in Implantable Cardioverter Defibrillators Trial" (SENSE Trial) is to assess the efficacy of a implantable cardioverter-defibrillator (ICD) lead with dedicated atrial sensing dipoles in detecting atrial high rate episodes.

The study hypothesis is that an ICD system with a lead with dedicated atrial sensing dipoles will have a diagnostic yield comparable to that of a standard dual chamber ICD system and superior to that of a standard single chamber ICD system.

The SENSE Trial is designed to study the efficacy of the DX System in detection of atrial high rate episodes (AHREs) in subjects with no prior history of atrial fibrillation. The DX System, or "DX," consists of a Biotronik DX ICD, and the Biotronik Linox Smart S DX lead which is an FDA approved ICD system that incorporates use of an implantable cardioverter-defibrillator (ICD) lead with dedicated atrial sensing dipoles.

The SENSE Trial will be conducted at 8-12 U.S. sites. The lead coordinating site will be at Weill Cornell Medical College. Subjects will be followed for 1 year to assess for the primary endpoints of the trial.

Inclusion Criteria:

• Fulfills standard indications for ICD implantation
• Subject or legally authorized representative can provide written authorization per institutional requirements
• Subject is intended to be implanted with a complete Biotronik DX system (consisting of a Biotronik Ilesto 7 VR-T DX ICD or any future FDA approved Lumax VR-T DX ICD, and the Biotronik Linox Smart S DX lead), or has been implanted with a complete Biotronik DX system no more than 30 days prior to the date of consent
• Able to comply with Home Monitoring

Exclusion Criteria:

• Subject has prior diagnosis of atrial fibrillation or atrial flutter
• Subject has need for atrial pacing
• Subject unwilling or unable to give informed consent or participate in follow-up
• Subject is unable to comply with Home Monitoring
• Subject is pregnant
• Subject has less than one year estimated life expectancy
• Subject was implanted with a cardiac device capable of detecting AHREs prior to implantation of the Biotronik DX system
• Subject was implanted with Biotronik DX system and had an AHRE detection before enrollment

Subjects with standard indications for implantable cardioverter-defibrillator implantation and no prior history of atrial fibrillation