Ventricular Arrhythmias Induced hy Electrical Cardioversion in Digitalised Patients

Abstract

The aim of this study was to determine whether electrical cardioversion is safe in digitalised patients who have no clinical or electrocardiographic evidence of digoxin toxicity. We retrospectively analysed the occurrence of immediate post-cardioversion ventricular arrhythmias in 50 patients receiving standard doses of digoxin and without evidence of toxicity (digoxin group) and compared them to 33 patients not receiving digoxin who were cardioverted in the same time period (control group). 10 patients (20%) in the digoxin group developed postcardioversion ventricular arrhythmias (non-sustained tachycardia, multifocal ectopics and bigeminy) compared to 1 patient (3%) in the control group (p < 0.05). Other relevant variables in the two groups were compared using univariate and multivariate analysis. The use of digoxin was the only variable found to be independently associated with the occurrence of arrhythmia (p < 0.05). With the cardioversion protocol used in this study digitalised patients had an increased incidence of post-cardioversion ventricular arrhythmias, even in the absence of clinical and electrocardiographic features of digoxin toxicity, and these arrhythmias may represent an increased risk of ventricular fibrillation.