Hyperkalemic Conduction Disturbances

Abstract

Elsewhere in this issue (p 86), Gould reports reversible His-ventricle interval (H-V) prolongation resulting from hyperkalemia. This observation is consistent with recent experimental and clinical studies. Ettinger and co-workers 1 administered toxic amounts of potassium ion to 30 dogs, and with intracardiac recording techniques were able to demonstrate severe depression of conduction in the atrioventricular node (proximal to the His bundle), His-Purkinje system (distal to the His bundle), and ventricular myocardium. We 2,3 recently reported electrocardiographic and some intracardiac electrophysiological observations in eight hyperkalemic patients. These patients were shown to have disordered impulse conduction in the atria, atrioventricular junction, trifascicular conduction system (His-Purkinje system), and in the ventricular myocardium. The sites of most severe conduction depression varied from patient to patient. Questions can be raised as to the clinical importance of these recent observations, since it is known from earlier studies that hyperkalemia can produce cardiac conduction disturbance, depresses myocardial