Study Description The purpose of this study is to compare the defibrillation efficacy between
the 50/50% tilt biphasic waveform and the Tuned biphasic waveform utilizing High Voltage Lead
Integrity Check (HVLIC) impedance.
Hypothesis The Tuned waveform reduces defibrillation thresholds (DFTs) when compared to the
50/50% tilt waveform.
- This is an acute, paired-sample, randomized (waveform testing sequence) study
- Patients are implanted with an Food and Drug Administration (FDA) approved St. Jude
Medical (SJM) EpicTM+ DR/VR Implantable Cardioverter Defibrillator (or any other
standard output ICD after Epic+) and defibrillation lead system.
- All study testing is completed at implant.
- Patients are randomized to begin DFT testing with either the 50/50% tilt or Tuned
- The HVLIC feature is used to measure the high voltage lead impedance and to program the
Tuned and 50/50% tilt waveform pulse widths.
- The DFT is determined by an optimized binary search method that is designed to reduce
the overall number of VF inductions to an average of 5.13 while maintaining very high
resolution and accuracy.
- Total # of centers - 15 centers
- Sample size - 60 patients