Table I.

Inclusion and Exclusion Criteria

Inclusion Criteria

Patients who meet current indications for a BSC CRT-D device with the SmartDelay algorithm

Willing and capable of undergoing a device implant and participating in all testing

Stable optimal pharmacologic therapy including diuretics, β-blockers, and ACE inhibition

Expected to be in sinus rhythm at the time of implant

Life expectancy of more than 360 days, per physician’s discretion

Geographically stable and willing to comply with the required follow-up schedule

Age 18 or above, or of legal age to give informed consent specific to state and national law

Exclusion Criteria

Complete heart block, or who otherwise are unable to tolerate pacing at VVI-40-RV for up to 14 days (e.g., persistent 2:1 AV block)

Previously received cardiac resynchronization therapy

Undergoing an upgrade of a pacemaker or implantable cardioverter defibrillator who are unable to tolerate pacing at VVI-40-RV for up to 14 days (e.g., heart block)

Expected to receive a heart transplant during the course of the study

Cardiac surgeries or procedures planned to be performed during the course of the study

Currently have or who are likely to receive a tricuspid valve prosthesis (mechanical right valve)

Neuromuscular, orthopedic, or other noncardiac condition that prevents normal, unsupported walking (i.e., canes, crutches, or walkers)

Pregnant or planning to become pregnant during the study (method of assessment upon physician’s discretion)

Currently enrolled in another investigational study or registry that would directly impact the treatment or outcome of the current study.

BSC = Boston Scientific.