Acute defibrillation performance of a novel, non-transvenous shock pathway in adult ICD indicated patients.

Objectives: The purpose of this study was to evaluate the efficacy of a totally subcutaneous, anteroposterior defibrillation shock pathway using a long time-constant shock waveform that emulates a proposed device having approximately twice the capacitance and thus twice the available energy of traditional transvenous devices.

Background: A non-transvenous defibrillation system potentially offers advantages over a transvenous system including simplification of the implant procedure and reduction of the impact of device complications by eliminating the need to place a lead within the heart. Previous non-transvenous defibrillation efficacy studies have been reported using anterolateral and anterior-anterior shock vectors.

Improved defibrillation efficacy with an ascending ramp waveform in humans.

Objectives: The purpose of this study was to compare an ascending ramp waveform (RAMP) with a standard, clinically available biphasic truncated exponential waveform (BTE) for defibrillation in humans.

Background: In animal studies, RAMP had a lower defibrillation threshold (DFT) than BTE.

Methods: We studied 63 patients at implantable cardioverter-defibrillator placement using a dual-coil lead and left pectoral active can.