Mineralocorticoid Receptor, Coronary Microvascular Function, and Cardiac Efficiency in Hypertension

Inclusion Criteria: 1. History of hypertension 1. Seated systolic BP \< 180 mmHg and diastolic \< 110 mmHg if on antihypertensives 2. Seated systolic BP 141-200 mmHg and/or diastolic BP 90-114 mmHg if not on antihypertensives 2. LVH by echocardiogram 1. For men: interventricular septum thickness ≥ 12mm 2. For women: interventricular septum thickness ≥ 11mm 3. We will also allow inclusion of people with treated hypothyroidism, pre-diabetes and diabetes controlled by diet, exercise, and/or metformin. Exclusion Criteria: * Use of MR antagonist (eplerenone, spironolactone, or finerenone) or amiloride (amiloride inhibits ENaC, which is a key mediator of MR's actions) within the past year * Orthostatic hypotension * Major medical illness, including uncontrolled diabetes mellitus (Hemoglobin A1c \>7.5) * LV ejection fraction \< 40% * New York Heart Association class III to IV congestive heart failure or unstable angina * A history in the prior 6 months of Q-wave myocardial infarction, stroke, transient ischemic attack, percutaneous transluminal coronary angioplasty, or coronary artery bypass graft * History of secondary hypertension * Known genetic cardiomyopathy * Renal disease (seum creatinine \>1.5 mg/dL for men and \>1.3 mg/dL for women) * Hepatic disease * Bronchospastic lung disease * Alcohol or substance abuse * Hormone replacement therapy * Abnormal values for electrolytes, liver enzymes or TSH * Pregnancy or lactation * All individuals \<18 and \>75 years will be excluded due to safety concerns of administering an angiotensin-II infusion in these patient groups.