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Plasma renin activity in chagasic patients with and without congestive heart failure
G Bellabarba1, D F Davila, A Torres
1Centro Cardiovascular, Universidad de Los Andes, Venezuela.
Insights
Chagasic patients with heart failure show activated renin-angiotensin-aldosterone system, indicated by higher plasma renin activity. This activation correlates with heart rate and ventricular dysfunction in symptomatic individuals.
Area of Science:
- Cardiology
- Endocrinology
- Parasitology
Background:
- Fluid retention in advanced Chagasic heart disease is linked to the renin-angiotensin-aldosterone system.
- Congestive symptoms in Chagas disease suggest potential activation of this hormonal system.
Purpose of the Study:
- To investigate baseline plasma renin activity (PRA) in Chagasic patients with and without congestive heart failure.
- To correlate PRA levels with clinical and hemodynamic parameters in Chagas disease.
Main Methods:
- Studied 28 Chagasic patients (19 asymptomatic, 9 symptomatic) and compared PRA to controls.
- Utilized cardiac catheterization and ventricular cineangiography in 20 patients.
- Measured plasma renin activity baseline values.
Main Results:
- Symptomatic Chagasic patients exhibited significantly higher PRA (4.11 ng/ml/h) than asymptomatic patients (1.08 ng/ml/h) and controls (1.65 ng/ml/h).
- PRA correlated directly with heart rate, left ventricular end-diastolic pressure, and ventricular volumes in symptomatic patients.
- Hemodynamic findings in symptomatic patients included larger ventricular volumes, reduced ejection fraction, and elevated filling pressures.
Conclusions:
- Chagasic patients with heart failure and fluid retention demonstrate activation of the renin-angiotensin-aldosterone system.
- Elevated PRA is associated with left ventricular systolic dysfunction and adverse hemodynamic changes in Chagas disease.
Abstract:
Chagasic patients with advanced heart disease have fluid retention-dependent symptoms. Since fluid retention is mostly dependent on the renin-angiotensin-aldosterone system, chagasic patients with congestion related symptoms should have activation of the renin-angiotensin-aldosterone system. The purpose of this investigation was to determine the plasma renin activity baseline values of chagasic patients with and without congestive heart failure. Twenty-eight patients with positive serology for Chagas' disease were studied. Nineteen patients were asymptomatic (functional class I New York Heart Association) and nine were symptomatic (functional classes II-IV). Cardiac catheterization and ventricular cineangiography were performed on 20 patients. The symptomatic patients had significantly higher plasma renin activity levels (4.11 +/- 1.03 ng/ml/h) than the asymptomatic patients (1.08 +/- 0.11 ng/ml/h, P < 0.001) and the normal sedentary controls (1.65 +/- 0.22 ng/ml/h, P < 0.05, mean +/- S.E.). The plasma renin activity baseline values of the asymptomatic and symptomatic patients correlated directly with the baseline heart rate (r = 0.77, P < 0.0001). The symptomatic patients had larger ventricular volumes, moderately depressed ejection fractions and increased left ventricular end-diastolic pressures. The plasma renin activity baseline values also correlated directly with the left ventricular diastolic pressures (r = 0.70, P < 0.0006) and with the left ventricular diastolic (r = 0.66, P < 0.001) and systolic volumes (r = 0.67, P < 0.001). These results indicate that chagasic patients with fluid retention-dependent symptoms and hemodynamic evidence of left ventricular systolic dysfunction have activation of the renin-angiotensin-aldosterone system.