Model 20105 Lead Study

Inclusion Criteria: * Subject has Cardiac pacing indication for sinus node dysfunction (dual chamber pacemaker) * Subject has signed and dated the study-specific informed consent form * Subject is 18 years of age or older * Subject is willing, able and committed to participate in Baseline and Follow-up and study procedures for the full length of the study Exclusion Criteria: * Subject is indicated for BiV pacemaker or ICD * Subject is pacing dependent * Subject has a previous Pacemaker System * Subject has known coronary venous vasculature that is inadequate for lead placement * Subject has unstable angina pectoris or has had an acute myocardial infarction (MI) within the last month * Subject has had a coronary artery bypass graft (CABG) or percutaneous transluminal coronary angioplasty (PTCA) within the past three months * Subject is not in sinus rhythm at implant * Subject has had a heart transplant (patients waiting for heart transplants are allowed in the study) * Subject has known renal insufficiency that would prevent them from receiving an occlusive venogram during the implant procedure * Subject is contraindicated for \<1mg dexamethasone acetate * Subject is enrolled in any concurrent drug and/or device study that may confound the results of this study * Subject has a terminal illness and is not expected to survive more than 6 months * Subject is a pregnant woman or woman of childbearing potential not on adequate birth control. * Subject is employed by Medtronic or by the department of any of the investigators or is a close relative of any of the investigators. * Legal incapacity or evidence that a subject cannot understand the purpose and risks of the study * Subject meets exclusion criteria required by local law. * Subject is unable to tolerate an urgent thoracotomy