Electroversion after verapamil administration

Forty-nine consecutive patients (44 with atrial fibrillation and five with atrial flutter) received 10 mg of verapamil five to seven minutes before elective electroversion, to evaluate the feasibility of the latter while verapamil effects were present. Excluded were patients with moderate-to-severe heart failure, acute myocardial infarction, mean ventricular rate lower than 70 beats/minute, those receiving any antiarrhythmic drug other than digoxin, and those in whom sinus node dysfunction was suspected. In six patients, eight complications took place: four instances of hypotension (systolic blood pressure below 80 mm Hg), two instances of junctional escape rhythm (47 and 63 beats/minute) and two instances of junctional tachycardia. In all four instances of hypotension, return to normal values of blood pressure was spontaneous (within five minutes in three patients). Rhythm disturbances were transient, without clinical relevance. This study suggests that electroversion can be safely carried out during clinical action of verapamil in properly selected patients, and that occasional, self-limited hypotension is the only complication of clinical significance to be expected.