Renin-aldosterone regulation during upright posture in young men with mitral valve prolapse syndrome

Previous studies have shown that symptom complex in patients with mitral valve prolapse syndrome (MVPS) may result from various forms of autonomic dysfunction. However, the interaction between adrenergic activity and renin release has not been studied. The purpose of this investigation was to assess changes in plasma renin activity (PRA) and plasma aldosterone in response to prolonged orthostatic stimulation in 19 young men with MVPS when compared to age- and sex-matched 20 control subjects. Heart rate was measured, and blood samples for PRA and aldosterone were obtained in the supine position and 90 min after assuming an upright position and slow walk. With posture the heart rate increase was greater in patients with MVPS in comparison with control subjects (19 +/- 9 vs. 12 +/- 8 beats per min, p < 0.05). Also an increase of PRA during upright activity was significantly greater in patients with MVPS (control 1.0 +/- 0.5 ng angiotensin I/mlxh, MVPS 1.8 +/- 1.7 ng angiotensin I/mlxh; p < 0.05). A significant correlation (r = 0.52, p < 0.05) was found between a rise of heart rate and PRA in patients with MVPS, but not in the control subjects. During prolonged upright activity aldosterone increased significantly in control subjects (at rest 74 +/- 41 pg/ml, with posture 98 +/- 68 pg/ml, p < 0.05) but did not change in patients with MVPS (at rest 64 +/- 29 pg/ml, with posture 67 +/- 26 pg/ml, NS).(ABSTRACT TRUNCATED AT 250 WORDS)