Study of Defibrillation Testing In Patients Undergoing Initial ICD Implantation

Implantable cardioverter-defibrillators (ICDs) are the most effective treatment for the
primary and secondary prevention of sudden cardiac death (SCD). At the time of ICD
implantation, ventricular fibrillation (VF) is typically induced to demonstrate effective
arrhythmia termination by the implanted device. Although defibrillation threshold (DFT)
testing with induction of VF at time of ICD insertion is currently considered the "standard
of care," and instructions for usage of devices approved by the Food and Drug Administration
(FDA) include labeling with DFT testing, the value of defibrillation testing with modern-day
devices has been questioned. Defibrillation testing can be associated with serious
complications and may add to the cost of the procedure.

It is hypothesized that patients who do not undergo defibrillation testing will have
outcomes similar to those who do undergo defibrillation testing at the time of initial
implantation. This pilot study is being performed to determine the feasibility of performing
a larger, multi-center clinical trial with longer follow-up to investigate whether or not
defibrillation testing will have any impact on overall mortality, implant complications, or
long-term first shock efficacy during clinical follow-up.

Inclusion Criteria:

- Age ≥ 18 years

- Initial ICD implantation (single, dual, or CRT) for a standard Class I or Class II
indication according to the ACC/AHA/HRS practice guidelines

- Anticipated life expectancy >6 months

Exclusion Criteria:

- Contraindications to defibrillation testing as determined by the managing physician*

- ICD replacement implants

- Right-sided pectoral implants

- Abdominal implants

- Chronic oral amiodarone therapy (for >6 weeks and continued need for amiodarone)

- Inability to give informed consent

- Contraindications to defibrillation testing include the following: hemodynamic
instability, LA thrombus, atrial fibrillation without adequate anticoagulation,
LV thrombus, recent CVA or TIA, severe unrevascularized coronary artery disease
or unstable angina, severe aortic stenosis, inotropic dependence, patient
refusal, other patient-specific medical conditions that are deemed as
contraindications, as determined by the implanting physician.