Abstract
Changes in the ventricular fibrillation threshold (VFRT) were studied in 81 dogs to evaluate quantitatively the effect of some newer antiarrhythmic agents (G-I-K solution, Xylocaine and Dilantin) on the susceptibility of the dog's heart to fibrillation in acute myocardial infarction. VFRT was measured in dogs with occlusion of the anterior descending branch of the left coronary artery by a single bipolar stimulation of square pulse of 10 msec duration delivered during the vulnerable period. VFRT fell to an average of 30 per cent of control levels following coronary ligation. A significant elevation of the initial low post-ligation threshold was demonstrated by the application of these agents. It is suggested that the clinical use of G-I-K solution, Xylocaine and Dilantin is recommended to protect against ventricular fibrillation, one of the commonest cause of death following acute myocardial infarction.
