Polygraphic studies of the effect of nitroglycerin in patients with ischaemic heart disease.

Polygraphic recordings were made before and after o6 mg of sublingual nitroglycerin in 20 normal subjects and in 20 patients with ischaemic heart disease. Thefollowing effects of nitroglycerin were observed in both groups: shortening of ejection time, prolongation of pre-ejection period and also of isometric contraction time unrelated to decrease in systolic blood pressure, and increase in heart rate; in the apex cardiogram, retraction of the systolic wave and diminution in amplitude of the A wave which approached the ventricular wave; in the carotid arterial pulse, decrease in the level of the dicrotic notch, disappearance of the tidal wave, and augmentation of the dicrotic wave. When compared with the normalgroup, pre-ejection period and isometric contraction time were significantly