Increasing Detection of Sub-Clinical Atrial Fibrillation in Defibrillator Patients With the Use of a VDD-ICD Lead

Increasing Detection of Sub-Clinical Atrial Fibrillation in Defibrillator Patients With the Use of a VDD-ICD Lead: The Dx-AF Study

This study aims to compare the Dx-ICD system (experimental) to standard VVI-ICD (control) on the ability to diagnose silent AF in patients without prior AF receiving an ICD for standard indications.

Recipients of implantable defibrillators (ICD) are at high risk of developing both AF and stroke, given the presence of multiple cardiovascular risk factors. Oral anticoagulation can prevent most strokes in patients with AF; provided that AF is recognized before a stroke occurs. Up to about 40% of incident AF may be sub-clinical, producing minimal or no symptoms, or being too short to allow detection.

DX AF is a prospective, randomized-controlled, open-label trial. Patients who are identified on clinical grounds for a single-chamber ICD will be randomized to a VDD ICD (experimental group) or single chamber ICD (control group).

The study will compare the Dx-ICD system (experimental) to standard VVI-ICD (control) on the ability to diagnose silent AF in patients without prior AF receiving an ICD for standard indications.

Inclusion Criteria:

• Patients with ischemic or non-ischemic cardiomyopathy,
• LVEF<50%, scheduled for primary or secondary prevention ICD
• Treating physicians feel that the use of single chamber ICD is appropriate
• No ECG-documented history of AF or flutter
• Age > 50 years

Exclusion Criteria:

• Known AF or flutter
• Current use of class I or III anti-arrhythmic medications
• Participants unwilling to attend study follow-up visits, considered unreliable for compliance or with an anticipated life expectancy less than 3 years