[Does nitroglycerin show the properties of a selective venodilator?].

The central hemodynamic effect of continuous intravenous nitroglycerin infusion at an increasing rate (0.01-0.1 microg x kg(-1) x min(-1)) was evaluated by noninvasive (tetrapolar rheography) and invasive (pulmonary arterial catheterization) techniques. The study included 10 healthy volunteers and 30 patients having usual indications for nitroglycerin infusion. The findings suggest that when even infused at low rates, nitroglycerin canses mainly arteriolar vasodilatation, which appears as increased stroke volume due to the predominance of diminished postload over lowered preload. It is obvious that the notion of nitroglycerin as a selective venodilator should be revised.