Left ventricular contractile function was evaluated in twenty patients with coronary artery disease before and during handgrip by use of Vpm, VCEIO and Vmax (obtained with a simplified calculation) from high-fidelity pressure measurements. In eight patients the response to handgrip was characterized by an increase of the contractile indices accompanied by small changes of left ventricular end-diastolic pressure (not exceeding + 4 mm Hg) and was considered normal. Twelve patients who showed abnormal or pathologic reaction to isometric exercise repeated handgrip after administration of 0.4 mg of spray nitroglycerin. Thus eight patients normalized their response to exercise, while in four we observed again a pathologic reaction to handgrip. It is concluded that is a useful and simple manoeuvre for a better evaluation of left centricular function in patients with coronary artery disease; the repetition of the test after administration of nitroglycerin can be useful in identifying those patients with greatest contractile reserve.