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.