Influence of sympathetic nerve activity on ventricular arrhythmogenicity in the dog with chronic hypokalemia

To examine the influence of sympathetic nerve activity on ventricular arrhyth mogenicity in the dog with chronic hypokalemia, an electrophysiologic study was performed before and after bilateral stellectomy (BS) in 10 dogs with chronic hypokalemia (2.8 ± 0.1 mEq/L), which was created by feeding a low-potassium diet and by administering furosemide over a four-week period, and the results were compared with those obtained from 10 dogs with normokalemia (4.7 ± 0.3 mEq/L) from being fed an ordinary diet over a four-week period.Before BS the incidence of electrically induced ventricular arrhythmias was higher in the hypokalemic than in the normokalemic dogs. After BS it was decreased considerably in the hypokalemic but not in the normokalemic dogs. Heterogeneity of effective refractory period (ΔERP), which was determined as the difference between the longest and shortest effective refractory periods in three sites of the right and left ventricles, was greater in the hypokalemic than in the normokalemic dogs be...