Menopausal Hormone Therapy And Left Ventricular Function

The purpose of this study is to compare left ventricular stroke volume and heart rate responses to bursts of SNA between PMF using, and not using, MHT.

Inclusion Criteria • \>45-60\< years of age Exclusion Criteria * Male sex * Females between STRAW+10 stages -5 and 0 * PMF in STRAW+10 stage +2 * PMF using oral hormone therapy * Females who entered menopause due to a surgical procedure or in response to pharmacotherapy (e.g., gonadotrophin releasing hormone agonists or chemotherapy) * Heart disease such as hypertropic cardiomyopathy, congenital abnormalities, chronic heart failure, valve disease, and a history of myocardial infarction * Medications that impact the central nervous system including selective serotonin reuptake inhibitors, anxiolytics, sedatives, anticholinergic agents, dopamine, amphetamines, or wake-promoting agents (e.g., modafinil). Other medications will be evaluated on an individual basis by the PI. * Cardiovascular medications is also an exclusion criterion which includes those acting on the renin-angiotensin-aldosterone axis, adrenergic receptor antagonists, diuretics, nitrates, and calcium channel antagonists. Other medications will be evaluated on an individual basis by the PI. * Pregnancy * COPD * Diabetes * CKD * Raynaud's phenomenon * Sleep disorders * Shift workers * BMI ≥40.0kg/m2 * Use of nicotine-containing products within the two years preceding study visits * Active cancer treatment