Pacemakers are implantable devices that pace (electrically stimulate) the heart. Some pacemakers have special programs to treat irregular atrial rhythms(top chambers of the heart beat too fast or too slow). Advances in pacemaker technology in recent years include features that automatically adapt to patient conditions without intervention from the clinician. Adapta (Model #ADDR01) is a new pacemaker that is designed to provide further automaticity advances by including the managed ventricular pacing (MVP) feature designed to promote intrinsic conduction (natural flow of electricity in the heart) by reducing unnecessary ventricular (lower chamber of the heart) pacing (electrical impulses). Adapta also contains a feature called TherapyGuide that is designed to allow the user to select certain conditions for each subject and receive a list of suggested pacemaker parameter value changes based on those conditions. The purpose of this study is to evaluate the overall system safety and clinical performance of the Adapta pacing system.

Inclusion Criteria:

• Subjects who have a Class I or II indication for implantation of a dual chamber pacemaker according to ACC/AHA/NASPE guidelines
• Subjects who have signed a Medical Ethics Committee (MEC) approved Informed Consent Form

Exclusion Criteria:

• Subjects with a mechanical tricuspid valve
• Subjects with a life expectancy less than two years
• Subjects with a Class III indication for permanent pacing
• Subjects with lead integrity problems, unless leads are being replaced