Complications in 220 patients with cardiac dysrhythmias treated by phased direct current shock, and indications for electroconversion.

Direct current shock is more effective than alternating current in the treatment of ventricular dys-rhythmias (Lown et al., 1962) and is more effective than drug therapy in converting supraventricular dysrhythmias to sinus rhythm (McDonald, Resne-kov, and O'Brien, 1964). Although earlier reports stressed the benign nature of the treatment (Lown, 1964; Morris et al., 1964), it has already been shown that it may lead to potentially serious complications (McDonald and Resnekov, 1965; Resnekov and McDonald, 1965). In this paper complications following the use of phased direct current (DC) shock, in the management of 220 consecutive patients with supraventricular dysrhythmias and ventricular tachycardia, are analysed. Studies were made on 220 patients (Table I) with atrial fibrillation, atrial flutter, atrial tachycardia, and ventricu-lar tachycardia who were treated with direct current shock by methods previously described (McDonald et al., 1964). If the patient was on digitalis, it was stopped for at least 24 hours before treatment. Light general anasthesia was used in all except 1 patient (Gilston, Fordham, and Resnekov, 1965). The 220 primary episodes of treatment were consecutive, and patients were not excluded because they were too ill. The duration of the dysrhythmias, the, grade of the patient's disability, and the nature and severity of any underlying heart disease were noted at the time of clinical examination. A 12-lead electrocardiogram was recorded in every patient and chest radiographs taken. The cardiothoracic ratio (CTR%) (Danzer, 1919) was calculated and the size ofthe left atriumgraded (Resnekov, 1965). The erythrocyte sedimentation rate (ESR) was measured by a modification of Westergren's technique (Dawson, 1960). Serum levels of the glutamic oxaloacetic transaminase were measured by the Sigma-Frankel technique (1956, 1961) and of the lactic dehydro-genase by the technique of Berger and Broida (1957, 1960); the levels of blood urea and serum electrolytes were estimated in all patients receiving diuretic therapy.