Inclusion Criteria:

• Meets current pacemaker implantation indications
• Likely to be chronotropically incompetent (i.e. unable to achieve appropriate heart rate during activity or does not have intrinsic atrial heart rates above 120 bpm, per physician judgment)
• Willing and capable of providing informed consent for participation
• Receiving a dual-chamber pacemaker
• Plans to remain in the long-term care of his/her enrolling physician and is available for study follow-up for three months post-implant

Exclusion Criteria:

• Mobitz II second degree heart block
• Third degree heart block
• Chronic atrial fibrillation or uncontrolled atrial arrhythmias within the past 90 days prior to consent
• Neuromuscular, orthopedic, or vascular disability that prevents normal walking or weight carrying (e.g., intermittent claudication, arthritis, residual stroke weakness, need for a wheelchair or walker)
• A symptom-limited exercise protocol is thought to be dangerous or contra-indicated, including but not limited to changing pattern of chest discomfort or uncontrolled arrhythmias

• Pulmonary disease as defined by any one of the following:

  • Forced Vital Capacity (FVC) or Forced Expiratory Volume in one second (FEV1) < 60% of predicted values
  • Use of two or more pulmonary inhalers
  • Use of supplemental oxygen
  • Chronic use of oral steroids for pulmonary disease treatment
• Life expectancy is less than 12 months due to other medical conditions, per physician discretion
• Has or indicated for an implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy-defibrillator (CRT-D)
• Currently enrolled in another investigational study that would directly impact the treatment or outcome of the current study.
• Younger than 18 years of age
• Pregnant or planning to become pregnant during the study (method of assessment upon physician's discretion)
• Unable or unwilling to comply with the protocol requirements