Effect of Right Ventricular Lead Position on Defibrillation Threshold

The investigators propose a prospective, pseudo-randomized study of patients who are electing
to undergo implantation of an implantable cardioverter defibrillator (ICD).

There are two locations in the heart in which ICDs are normally implanted: the apex and the
septum. The purpose of this study is to determine whether the ICD performs better in one
location or the other, as measured by defibrillation threshold. In this study, both locations
will be tested in each patient. The final location will be determined by the implanting
physician as the location that is best for the patient.

Inclusion Criteria:

- Patient indicates for single-chamber (VR), dual-chamber (DR) or resynchronization
CRT-D) implantable defibrillator

- Left-sided implant

- Single coil or dual coil (single coil for testing)

- Age ≥ 18 years of age

- Ability to consent

- Medically stable, in the opinion of the implanting physician, to undergo
defibrillation safety margin testing

- Procedure performed under conscious sedation

- English-speaking

Exclusion Criteria:

- Patient unable to understand and consent to the procedure on his or her own

- Pregnant or breastfeeding patients

- New York Heart Association (NYHA) Class IV

- Patients with pre-existing RV leads

- Pacemaker dependent

- Patient medically unstable to undergo defibrillation testing (e.g., high risk for deep
sedation; patients that develop respiratory compromise or hemodynamic instability from
the sedation)

- Patients that require general anesthesia instead of conscious sedation

- Patients <18 years of age

- Non-English-speaking