Ectopic Beats and Atrioventricular Conduction Disturbances

Abstract

PERFUSION with potassium deficient solutions induces ectopic rhythms and atrioventricular (AV) conduction disturbances in isolated rabbit hearts.^1,2In dogs and in man, potassium loss sensitizes the heart to digitalis intoxication which is manifested by ectopic beats, ectopic rhythms and AV conduction disturbances.³Levine⁴suggested that potassium loss may precipitate various arrhythmias, particularly supraventricular tachycardia, in patients receiving and in patients not receiving digitalis. Recently Fisch and co-workers⁵have reviewed many case reports of patients in whom ectopic beats and AV conduction disturbances were attributed to potassium deficiency or hypopotassemia. Surawicz and Lepeschkin⁶studied electrocardiograms of 25 patients with hypopotassemia and found that all four patients with plasma potassium concentration less than 2.6 mEq/liter had ectopic beats. In another study,⁷13 of 50 patients with plasma potassium concentration less than 3.5 mEq/liter had ectopic beats. Weaver and Burchell⁸found ectopic atrial beats in