External Body Pressure in Heart Failure With Preserved Ejection Fraction

* Heart Failure Study Population * Inclusion Criteria (Aim 1 and 2): * Age greater than or equal to 30 yrs * Established diagnosis of HFpEF with left ventricular ejection fraction greater than or equal to 50% * NYHA II-III symptoms * Stable HF drug regimen for the preceding 1 month * Wedge pressure greater than or equal to 15 mmHg at rest or greater than or equal to 25 mmHg with peak exercise * (For Aim 2 only) Scheduled for an elective right heart catheterization at Duke University Hospital. * Exclusion Criteria (Aim 1 and 2): * HF hospitalization for type I myocardial infarction within 3 months * Infiltrative (ie amyloid) or hypertrophic cardiomyopathy * Uncontrolled atrial or ventricular arrhythmia * Chronic oxygen use * History of vasovagal syncope * Considered inappropriate to participate by PI or Sub-I * Healthy Volunteers (Controls) * Inclusion Criteria (Aim 1): * Age greater than or equal to 30 yrs * Able to speak English * Ambulatory \[assistive devices ok\] * Able to provide informed consent * Exclusion Criteria (Aim 1): * Acute myocardial infarction (3-5 days) * Unstable angina * Uncontrolled arrhythmia causing symptoms or haemodynamic compromise * Syncope * Active endocarditis * Acute myocarditis or pericarditis * Symptomatic severe aortic aneurysm * Uncontrolled asthma * Arterial desaturation at rest on room air \<85% * Untreated left main stem coronary stenosis * Asymptomatic severe aortic stenosis * Severe untreated arterial hypertension at rest (\>200 mm Hg systolic, \>120 mm Hg diastolic) * Tachyarrhythmias or bradyarrhythmias * Hypertrophic cardiomyopathy * Significant pulmonary hypertension * Thrombosis of the lower extremity until treated for a minimum of 2 weeks * Within 2 weeks of acute symptomatic pulmonary embolus * Abdominal aortic aneurysm \>8.0 cm * Electrolyte abnormalities * Pregnancy * Inmate of correctional facility (i.e. prisoner) * Diagnosed history of dementia * Inability to ambulate independently * Considered inappropriate to participate by Principal Investigator