Following randomization, subjects will have scheduled clinic visit follow-ups at 1, 3 and 6-month intervals. Relevant event history, cardiac medications, physical assessment, device interrogation/programming status and adverse events will be collected at each follow-up visit. At the 6-month visit, a repeat echocardiogram and a 12-lead ECG will be obtained. Subjects will be followed through the 6 month visit. After that, subjects will have a safety follow up contact at the end of the study. The study will end when the last randomized subject reaches the 6 months visit.