Calcium antagonism in heart and vascular smooth muscle.

Calcium antagonism is an unifying concept that offers a common denominator for a multitude of beneficial effects in cardiovascular therapy such as: direct reduction of myocardial energy expenditure and oxygen demand, improvement of myocardial oxygen supply resulting from spasmolytic and vasodilator effects on coronary trunk arteries (including collaterals and anastomoses), lowering of systemic arteriolar resistance (antihypertensive action), indirect diminition of cardiac oxygen requirement due to a fall in afterload, cardioprotection by prevention of excessive myocardial Ca uptake, damping effects on ectopic cardiac automaticity and on reentry pathways (not discussed in the present paper), and possibly anticalcinotic protection of the arterial walls at an advanced age or in cases of premature arterial senescence due to diabetes, hypertension, or nicotine intoxication.