Haemodynamics of orally-active converting enzyme inhibitor (SQ 14225) in hypertensive patients.

1. The haemodynamic effects of oral converting enzyme inhibitor (SQ 14225) were assessed in eight patients with severe essential or renovascular hypertension. 2. Mean arterial pressure fell (149 +/- 5 to 127 +/- 8 mmHg, P less than 0.02), because of a fall in total peripheral resistance (6.9 +/- 0.53 to 5.7 +/- 0.40 kPa 1(-1)s m2) without a significant change in cardiac index. Two of the eight patients were non-responders without pressure reduction or a haemodynamic change. Sodium restriction (10 mmol/day) while the same dose of SQ 14225 was continued further lowered arterial pressure (137 +/- 8 to 111 +/- 12 mmHg, P less than 0.05) through further resistance reduction (6.5 +/- 0.53 to 5.2 +/- 0.40 kPa 1(-1)s m2, P less than 0.05). 3. Haemodynamic responses to head-up tilt (increased heart rate and resistance, decreased cardiac index) were unaffected by SQ 14225 regardless of sodium intake. 4. The pattern of reduction in peripheral resistance, with unchanged cardiac index, was similar to that produced by vasodilators acting at both arteriolar and venular levels.