Acute hypokalemia and inducibility of ventricular tachyarrhythmia in a nonischemic canine model.

Inducibility of sustained ventricular tachycardia (VT) and ventricular fibrillation (VF) by programmed ventricular stimulation following acute hypokalemia was studied in 21 anesthetized dogs free of inducible ventricular tachyarrhythmias at baseline. The control mean serum potassium concentration of 3.65 mEq/L was decreased to 2.14 mEq/L by insulin and furosemide administration. Inducibility of arrhythmias was also assessed following isoproterenol infusion before and after induction of hypokalemia. None of the animals developed sustained VT. Only one animal developed VF following hypokalemia (p greater than 0.05). Two normokalemic animals and five hypokalemic animals developed VF following isoproterenol infusion; this difference was not significant (p greater than 0.05). In this study, hypokalemia did not predispose to the development of a substrate necessary for the genesis and maintenance of VT. The inducibility of VF following hypokalemia was not significantly enhanced and appears to be related to the "aggressive" stimulation protocol.