Acute Evaluation of the Safety of Left Ventricular-left Ventricular (LV-LV) Delays and Its Effects on Mechanical Dyssynchrony

Acute Evaluation of the Safety of LV-LV Delays and Its Effects on Mechanical Dyssynchrony

The purpose of this study is to evaluate the effects of various LV-LV delays during multi-site left ventricular (MSLV) pacing on mechanical dyssynchrony in cardiac resynchronization therapy (CRT) patients post-implant.

Inclusion Criteria:

1. Have an approved indication for a CRT implant
2. Undergoing or previously received the implant of a St. Jude Medical Promote Q 3221-36 CRT-D with a Quartet Model 1458Q LV lead at participating clinical study site
3. Ability to provide informed consent for study participation and be willing and able to comply with the prescribed evaluations

Exclusion Criteria:

1. Have persistent or permanent atrial fibrillation
2. Have an intrinsic heart rate of <50 beats per minute
3. Have Cheyne-Stokes breathing
4. Have undergone cardiac surgery or coronary revascularization procedure within 3 months prior to enrollment or be scheduled for such procedures
5. Have had a recent CVA or TIA within 3 months prior to enrollment
6. Be less than 18 years of age
7. Be pregnant