[Hemodynamic and electrocardiographic prolonged nitrate effect during frequency load in coronary disease]

Hemodynamic and electrocardiographic analysis during rapid right atrial stimulation was performed before and one, two, and four hours after oral application of longacting nitroglycerin (5 mg) and isosorbide dinitrate (20 mg) in 11 and 9 patients, respectively with coronary heart disease. Atrial stimulation without nitrate induced significant ischemic ST segment depression. Cardiac output showed a small decrease and the mean arterial, pulmonary artery, and pulmonary wedge pressure increased. Isosorbide dinitrate reduced the ischemic reaction by 40% from the first to the fourth hour after application. Cardiac output, stroke volume, aterial, pulmonary artery, and pulmonary wedge pressure also decreased continuously. Nitroglycerin caused a similar reduction of ischemic ST segment depression for two hours. Systolic, diastolic, and mean arterial pressure decreased significantly. Cardiac output, stroke volume, and pulmonary artery pressure remained unchanged. It was concluded that the applied dose of isosorbide dinitrate showed a more extensive longacting effect.