Effects of verapamil on infarct size following experimental coronary occlusion.

Open-chest anaesthetized dogs were given verapamil after left anterior descending artery occlusion, and ST-segment alterations and haemodynamic variables were monitored. Verapamil produced a highly significant reduction in ST-segment elevation in the epicardial electrocardiogram and prevented the haemodynamic deterioration seen in the control animals in which ST-segment elevation persisted. The apparent protective effect of verapamil in myocardial ischaemia is discussed in relation to its ability to inhibit selectively the transmembrane fluxes of calcium ions in excitable tissues.