Comparison of 50% Tilt and Tuned Waveforms in Single-Coil Active Can Configuration

Sudden Cardiac Death

The purpose of this study is to compare the defibrillation efficacy between the 50/50% tilt biphasic waveform and the Tuned biphasic waveform in a single coil active can configuration.

There has been one prospective study that found some benefit of using tuned waveforms over 50/50% tilt waveforms.11 Other studies have failed to show much change in defibrillation efficacy with different duration biphasic waveforms. A vast majority of patients in these studies were tested with dual coil leads. Although dual coil leads can lower defibrillation thresholds, it is known that dual coil leads can make the lead extraction difficult, lead to venous obstruction and are more prone to failure. Results from a recent study showed that that a single coil configuration is adequate in a vast majority of patients when DFT testing was performed with tuned waveforms. This makes the use of single-coil leads during ICD/ CRT-D implants an attractive option. Theoretical analysis has shown that difference between the tuned and 50% tilt waveforms is amplified at high impedance levels with tuned waveforms being superior (unpublished). Accordingly, this study has been designed to prospectively compare the DFT estimates with tuned and 50% tilt waveforms in left-sided, active pectoral defibrillation lead systems when the SVC coil has been turned OFF or is not part of the shocking circuit.

United States