Effect of preload and afterload on ventricular arrhythmogenesis.

To examine whether it is an increase in preload or afterload that may cause ventricular arrhythmias, the ventricles of 13 anesthetized open-chest dogs were bandaged. Next, metaraminol, an almost pure alpha stimulator, was given, followed by removal of the bandage. The ventricles were then sucked in a plastic cup, which was finally removed.