[The effects of nitroglycerin on coronary blood flow (author's transl)]

In the healthy myocardium, nitroglycerin (NG) produces vasodilatation by a double mechanism: direct action and reflex action through metabolic autoregulation. It also redistributes coronary blood in a manner which benefits the endocardium. In the ischaemic myocardium, the vasodilator effect of NG has not been conclusively demonstrated, yet there is no doubt that the drug redistributes blood in such a way as to benefit both the endocardium and the ischaemic areas. The mechanisms involved here are multiple (dilatation of the collateral vessels and intramural arteries, reduction of oxygen consumption, etc.) and act synergistically. However, the effects of NG on coronary blood flow cannot by themselves account for the anti-anginal properties of the drug, which are to a great extent directly or indirectly assisted by its peripheral systemic effects.