RecruitingDevice studyFast Induced Remodeling in Heart Failure With Preserved Ejection FractionFIRE-HFpEF is a multi-center, prospective, randomized, single-blinded, clinical feasibility study. This study will enroll up to 105 subjects with heart failure with preserved ejection fraction in the United States. Data will be collected to evaluate whether pacing therapies can lead to improvements in exercise capacity and health status of subjects.