DIGOXIN-INDUCED CONSTRICTION OF EPICARDIA L CORONARY-ARTERIES IN PATIENTS WITH CORONARY-ARTERY DISEASE - REVERSAL WITH NITROGLYCERIN

Heart diseases requiring glycoside therapy are often associated with c oronary artery disease. This study evaluated quantitatively the effect of an intravenous bolus injection of digoxin (0.8 mg) on diameters of epicardial coronary arteries in II patients with coronary artery dise ase. Coronary angiograms were taken up to 30 min following intravenous administration of glycosides. The maximum decrease in mean diameters of angiographically normal coronary segments was 10.0 +/- 3.5 % (p les s than or equal to 0.001) compared to control. Maximum reduction in mi nimal diameters of stenotic segments was 22.1 +/- 13.1% (p less than o r equal to 0.001). This vasoconstriction could be reversed with nitrog lycerin. Thus, intravenous administration of digoxin induces vasoconst riction of normal and stenotic coronary arteries, which could cause is chemic complications in the presence of high-grade stenoses. Since dig oxin-induced vasoconstriction could be reversed with nitroglycerin, co ncomitant vasodilator therapy is recommended.