Controlled study of intravenous nitroglycerin treatment for two days in patients with recent myocardial infarction

Abstract

Summary: Hemodynamic measurements were obtained for 48 h in 46 patients with recent myocardial infarction. Patients were randomized to treatment with (n = 22) and without nitroglycerin (NTG) (n = 24). In patients with diastolic pulmonary arterial pressure (PAEDP) <20 mmHg (group I), NTG decreased PAEDP from 15 to 1 1 mmHg (n = 13); in the untreated control group PAEDP remained unchanged (n = 15). Cardiac output decreased in the NTG group from 5.4 to 5.0 I/min and in the control group from 4.7 to 4.4 1 /min. Mean arterial pressure decreased in both groups, in the NTG group from 106 to 97 mmHg and in the control group from 102 to 94 mmHg.In patients with left ventricular failure and PAEDP >20 mmHg (group 11) the decrease in left ventricular filling pressure was significantly greater (25 to 17 mmHg, n = 9) than in the control group (24 to 20 mmHg, n = 9). Cardiac output increased during NTG treatment from 4.2 to 5.1 I/min. In the control group, however, cardiac output decreased from 4.2 to 3.6 I/min. Mean arterial pressure decreased from 103 to 95 mmHg in the NTG group and from 114 to 96 mmHg in the control group. Heart rate did not change significantly.Thus, PAEDP decreased significantly in patients who received NTG treatment for 48 h compared to an untreated control group. Cardiac output increased in treated patients, especially those with left ventricular failure, but decreased in the control group. Mean arterial pressure decreased to the same degree in treated patients and in controls.Key words: intravenous nitroglycerin, recent myocardial infarction, long-term effects, increase in cardiac output, decrease in diastolic pulmonary arterial pressure, untreated control group, spontaneous changes

Effects of continuous intravenous infusions of nitroglycerin on canine systemic and hind limb microcirculatory hemodynamics

“…27"28 Systemic venodilation accompanying nitroglycerin infusions tends to decrease myocardial preload and to reduce ventricular systolic and diastolic pressures, as well as dimensions. 27,28 These effects lead to lowered ventricular wall tension and therefore lessen myocardial oxygen demandY In the present study, massive cry stalloid volume loading prevented the anticipated reductions in blood pressure and cardiac work. This finding suggests that nitroglycerin might exert many of its clinical cff~:cts by systemic venodilation and resultant preload reduction.…”