[Effects of the parenteral administration of trinitroglycerin on myocardial function, coronary flow and myocardial oxygen consumption in the coronary artery disease patient (author's transl)].

An angiographic study, combined with the determination of coronary flow (thermodilution) and of coronary arteriovenous difference was performed in 10 patients with coronary artery disease under basal conditions and following an infusion of trinitroglycerine. The following changes were noted under the influence of trinitroglycerine: significant fall in left ventricular telediastolic pressure (40%), telediastolic volume (18%), telediastolic strain (53%), mean aortic pressure (11%) and mean systolic strain (21%). Significant increase in ejection fraction (8%), mean shortening (Vcf: 22%) and thickening (Vep: 22%) rates. Significant fall in coronary flow (11%) without any change in coronary arteriovenous difference. Decrease in myocardial oxygen consumption parallel to the reduction in mean systolic strain. These results indicate that the essential mechanism of haemodynamic and metabolic action of trinitroglycerine is located at the level of "load", in particular "preload".