[Effects of long-term therapy with losartan on baroreflex regulation of cardiovascular system]

Area of Science:

• Cardiology
• Pharmacology
• Physiology

Background:

• Ischemic heart disease (IHD) and cardiac failure (CF) significantly impact circulatory system parameters.
• Understanding the effects of medications like losartan on these parameters is crucial for patient management.

Purpose of the Study:

• To evaluate the impact of losartan on structural-functional circulatory parameters and cardiopulmonary baroreflex (CPBR) in IHD patients with CF.
• To assess changes in vascular tone, cardiac function, and baroreflex sensitivity during losartan therapy.

Main Methods:

• 14 male IHD patients with NYHA class II-III CF were treated with losartan (25-100 mg/day).
• Evaluations included echocardiography, radiocardiography, occlusion plethysmography, 131-I hippuran clearance, and CPBR assessment via forearm blood flow changes.
• Measurements were taken before and after treatment.

Main Results:

• Losartan treatment led to diminished venous tone and increased forearm blood flow.
• A reduction in circulating plasma volume and elevated hematocrit were observed.
• Left ventricular diastolic function showed improvement, but baroreflex dysfunction progressed.

Conclusions:

• Long-term losartan therapy benefits peripheral vascular tonicity and left ventricular diastolic function in IHD patients with CF.
• The treatment also reduces circulating plasma volume but is associated with a progression of baroreflex dysfunction.