Isosorbide dinitrate and intra-aortic balloon pumping in preinfarctional angina. Effects on central circulatory dynamics.

The dynamics of the central circulation were measured by a radionuclidic technique in 18 men with high-risk preinfarctional angina who received therapy with isosorbide dinitrate (n equals 18), intra-aortic balloon pumping (n equals 8), or both (n equals 8). Administration of 5 mg of isosorbide dinitrate sublinqually was associated with a reduction in stroke volume index (SVI), cardiac index (CI), systemic arterial blood pressure, and left ventricular end-diastolic volume (LVEDV) and with increased left ventricular ejection fraction (LVEF). Intra-aortic balloon pumping did not alter SVI or CI, but decreased systolic blood pressure and LVEDV and increased LVEF and diastolic blood pressure. The combination of therapy with isosorbide dinitrate and intraaortic balloon pumping resulted in decreased SVI, systolic blood pressure, and LVEDV and increased LVEF. Thus, therapy with isosorbide dinitrate reduced left ventricular preload, and intra-aortic balloon pumping reduced blood pressure, which resulted in a decreased LVEDV and an increase in LVEF. Therapy with isosorbide dinitrate and intra-aortic balloon pumping act to alter central circulatory dynamics in favor of reducing myocardial oxygen demand.