[Early detection of myocardial alterations in mitral insufficiency with the angiotensin test]. / Dépistage précoce des altérations myocardiques de l'insuffisance mitrale par le test à l'angiotensine.

Left ventricular function was assessed at rest and after increasing systemic arterial resistance by angiotensin in 40 patients with isolated mitral insufficiency. Angiotensin was administered intravenously at a dose of 0,4 micrograms/mn until the systolic blood pressure rose by at least 30 mm Hg. Left ventricular and aortic pressures, cardiac index and left ventriculography in the 30 degree right anterior oblique projection (50 frames per second) were recorded before and during angiotensin infusion. The mean rise in systolic left ventricular pressure was 40 +/- 2,8 mm Hg; the heart rate increased slightly but significantly; left ventricular and diastolic pressure rose from 12,0 +/- 1,0 to 24,0 +/- 1,2 mmHg. The systolic index (Fick's method) was significantly decreased (37 +/- 1,6 ml/m2 to 26 +/- 1,6 ml/m2) though the angiographic systolic index remained unchanged. This is explained by an increase in the regurgitant fraction (51 +/- 2,5% ao 65 +/- 3%). The end diastolic volume index was unchanged; the ejection fraction was significantly decreased. The resting hemodynamic status was only slightly disturbed in 29 patients (mean capillary pressure less than 15 mm Hg, 8,8 +/- 0,52 mmHg). The left ventricular function curves with angiotensin distinguished two groups of patients: Group A (20 patients) with left ventricular dysfunction induced by angiotensin, Group B (9 patients) who maintained the systolic index despite the increase in left ventricular end diastolic pressure. These results suggest that the angiotensin test may be useful for detecting early left ventricular dysfunction in patients with isolated mitral insufficiency and virtually normal resting hemodynamic parameters.