RESUMO
The effects of isosorbide dinitrate (ISDN) on the coronary and systemic circulation were evaluated in 8 children with angiographically normal coronary arteries. ISDN, 100 micrograms/kg, was given as a intracoronary injection. The pulmonary artery pressure, pulmonary capillary wedge pressure and left ventricular end diastolic pressure which are related to the pre-load were significantly reduced 1 min after the ISDN injection. The systolic blood pressure was reduced, and heart rate increased. The cardiac output, pressure-rate product and systemic vascular resistance showed no significant change. The systolic work index, however, was significantly reduced. ISDN induced a significant dilatation, ranging from 4.0% to 12.9%, in the diameter of the coronary vessels. There was, however, no change in the coronary blood flow, coronary perfusion pressure and coronary vascular resistance. The grade of the dilatation of the coronary vessels by ISDN in children was lower as compared with that in adult.