[Hemodynamic and coronary effects of isosorbide dinitrate: comparison of intravenous and intracoronary injection].

The hemodynamic and coronary effects of a single dose of 3 mg of isosorbide dinitrate (ISD) were studied in 26 patients after intra-coronary (17 cases) and intravenous injection (9 cases). The study was carried out after opacification of the coronary arteries and a 0,4 mg ergometrine test. The radiological contrast and ergometrine increased left ventricular end diastolic (10,4 +/- 0,89 mm Hg to 22,5 +/- 1,88 mm Hg) and systolic pressures (131,4 +/- 4,8 mm Hg to 158,7 +/- 5,8 mm Hg) without changing V max. After ergometrine, the diameter of the coronary vessels decreased by 8,8%. After ISD, these pressures fell significantly from the 10th second; the lowest pressure after ISD was related to the initial pressure at the end of the ergometrine test (systolic pressure Y = 0,68 X + 6,39, R = 0,89, p less than 0,001) ( end diastolic pressure : Y = 0,36 X + 0,17, R = 0,68 , p less than 0,01). Moderate transient tachycardia was probably a reflex reaction. The increase in V max, maximal after 1 to 2 minutes, seemed to have a different mechanism. The global effect is to decrease myocardial oxygen consumption as reflected by the fall in the tension - time - index (3083 +/- 2,13 to 2330 +/- 184 mm Hg . sec-1 . min . The diameter of the coronary vessels rose by 26% with respect to the smallest diameter observed after ergometrine. The intracoronary and intrafemoral venous injection gave identical hemodynamic and coronary changes from the first minute. The effects were maximal between 2 and 4 minutes and continued after 10 minutes. The only difference was a more rapid decrease in systolic pressure after intrafemoral administration. Dilatation occurred before the hemodynamic effects after intracoronary injection, which is an argument for using intracoronary ISD in the treatment of spasm induced by ergometrine.