The purpose of this study is to compare the defibrillation efficacy between the 50/50% tilt biphasic waveform and the Tuned biphasic waveform in patients with right-sided implants.

Current era implantable cardioverter defibrillators (ICDs) have high defibrillation efficacy. This has stimulated a debate about whether DFT testing should be performed at all.1-3 However, this dialog has primarily centered around left sided implants, a group that is characterized by a small incidence of high defibrillation thresholds (DFTs).

The mechanism of phase duration programming to improve DFTs would seem to be most effectively applied to a group of patients with a high incidence of high DFTs such as right sided implants. This study therefore aims to prospectively evaluate direct phase duration programming on DFTs in right sided implants.

Inclusion Criteria:

• Patient meets standard indication for an ICD/ CRT-D
• Patient will be implanted with an FDA approved SJM ICD/ CRT-D that has a higher capacitance (maximum delivered energy - 36 J)
• Pulse generator will be implanted on the right-side
• Patient is able to tolerate DFT testing.
• RV lead will be placed in the RV apex or inferior septum

Exclusion Criteria:

• Patient is pregnant.
• Patient is less than 18 years old.
• SVC coil was turned ON during DFT testing

Patients with approved ICD/CRT-D indications