[Control of afterload by intravenous nitroglycerin in patients undergoing myocardial revascularisation (author's transl)].

In 18 patients undergoing aortocoronary bypass grafting haemodynamic measurements were made before and after hypertensive episodes and intravenous administration of nitroglycerin (NTG). Patients of group I (n = 10) had good left heart function before operation. The mean arterial pressure (MAP) rose during the hypertensive episode from 82 +/- 12 mm Hg to 119 +/- 8 mm Hg (p less than 0.001), the pulmonary capillary wedge pressure (PCWP) increased from 11 +/- 3 mm Hg to 15 +/- 2 mm Hg (p less than 0.05). The cardiac index (CI) was not significantly altered. Infusion of NTG decreased the MAP to 84 +/- 3 mm Hg (p less than 0.001), the PCWP to 9 +/- 3 mm Hg (p less than 0.01). The CI remained unchanged. Patients of group II (n = 8) had poor left heart function before operation. During the hypertensive episode the MAP increased from 77 +/- 15 mm Hg to 115 +/- 6 mm Hg (p less than 0.001), the PCWP from 13 +/- 4 mm Hg to 25 +/- 5 mm Hg (p less than 0.001). The CI decreased from 2.2 +/- 0.3 1/min x m2 to 1.5 +/- 3.41/min x m2. Infusion of NTG decreased the MAP to 83 +/- 4 mm Hg (p less than 0.001), the PCWP to 11 +/- 3 mm Hg (p less than 0.001). The CI rose to 2.3 +/- 0.3 1/min x m2 (p less than 0.01). The authors conclude that NTG is an effective antihypertensive agent. No untoward side effects were noted.