REmodeling the Left Ventricle With Atrial Modulated Pacing

Inclusion Criteria:

- Subject has had a market released dual chamber Medtronic Pacemaker with a Sleep
function for at least 3 months

- Subject is stable on current medications

- Subject has dyspnea with exertion or diagnosed as NYHA Class II or III Heart Failure

- Subject has had a prior Echo in past 6 months with: EF ≥ 50% and Diastolic volume <80
ml/m²

- Subject has evidence of hypertrophy (indexed to body surface area: men 115 g/m², women
95 g/m² or indexed to height: men 49.2 g/m2.7, women 46.7 g/m2.7) or Relative Wall
thickness >0.42, or Wall Thickness>1.2cm (posterior wall)

- Subject is willing to sign and date the study Informed Consent Form (IC Form) -
Subject is 18 years of age or older, or of legal age to give informed consent per
local law

- Subject is expected to remain available for follow-up visits

Exclusion Criteria:

- Subject has permanent AF or AF noted on baseline interrogation rhythm strip

- Subject has uncontrolled BP; (systolic pressure needs to be >100mmHg and <160mmHg on
medications)

- Subject has severe stenosis of the aortic or mitral valve, defined as valve area ≤1.0
cm² or severe regurgitation of the aortic or mitral valve

- Subject has symptomatic Chronic Obstructive Pulmonary Disease (COPD) requiring oxygen

- Subject's Pacemaker has less than 6 months of Pacemaker battery life

- Subject had an aortic valve replacement (surgical or TAVR) procedure less than 9
months prior to enrollment

- Subject's programmed upper rate limit is less than 100 bpm because of concerns of
elevated pacing

- Subject is unable or unwilling to perform the 6 Minute Walk Test at all scheduled
study visits

- Subject is currently enrolled or planning to enroll in a potentially confounding trial
during the course of the study (co-enrollment in concurrent studies is only allowed
when documented pre-approval is obtained from the Medtronic study manager)

- Subject is pregnant

- Subject meets any exclusion criteria required by local law

- Subject's life expectancy is less than 12 weeks

- Subject with medical condition that precludes the patient from participation in the
opinion of the investigator

- Subject has known coronary disease with Class II angina