Role of isosorbide dinitrate in patients with unstable angina pectoris.

The development of hemodynamic facilities permitted observations after isosorbide dinitrate (ISDN) administration over a 4-hour period in patients with a history of unstable angina pectoris and documented anatomic coronary artery disease. The patients had no evidence of left ventricular failure and were free of pain during the period of sublingual and oral ISDN administration. Beneficial influences on venous return and arterial blood pressure were manifested as declines in preload and afterload, along with reduction in the mechanical work of the ventricle and, finally, increases in the diastolic compliance of the ventricle. These hemodynamic changes were shown to persist 8 to 12 times as long as the brief influence of nitroglycerin. Thus hemodynamic evidence was provided for the first time on the beneficial influence of oral and sublingual ISDN on venous, arterial, and left ventricular myocardial muscle in patients with unstable angina pectoris.