A biventricular ICD system with biventricular defibrillation.

We describe the case of a 59-year-old gentleman with severe dilated cardiomyopathy requiring implantation of a dual-chamber biventricular implantable cardioverter-defibrillator (ICD). High defibrillation thresholds (DFT) were encountered at implant with an inadequate defibrillation safety margin. Testing of all possible shock vectors/polarities with and without the SVC coil and optimization of the distal RV coil position all proved inadequate. A satisfactory defibrillation safety margin was achieved following placement of a second lead in the coronary sinus to enable biventricular defibrillation. This case highlights an additional strategy for combating high DFTs and is an option even in dual-chamber biventricular ICD systems.