[Cardioversion by internal electric shock of permanent atrial fibrillation]

A new technique for cardioversion of chronic atrial fibrillation was used in 17 patients whose arrhythmia had resisted all attempts at electrical and pharmacologycal cardioversion. Atrial fibrillation was badly tolerated by all patients despite digitalis administered alone (8 patients) or combined with amiodarone (9 patients). Twelve patients had left atrial dilatation at echocardiography. The 200, 300 or 400 joule electrical shock was delivered between the proximal pole of a quadripolar catheter (cathode) and a back plate (anode). The catheter was positioned at the His bundle recording site then withdrawn into the right atrium. The internal shock restored sinus rhythm in 15 patients (88 p. 100). Transient atrioventricular block (3-315 sec) was observed in 8 patients. Eleven patients were discharged in sinus rhythm. In 4 patients, the atrial fibrillation recurred on day 8 and after 2, 4 and 9 months. A second shock was attempted in two patients and succeeded in one. After a mean follow-up period of 14.8 +/- 8 months (range 2 to 25 months), 8 of the 11 patients successfully cardioverted (72 p. 100) or of the attempted reductions (47 p. 100) were in sinus rhythm. The remaining 9 patients were treated with antiarrhythmic drugs (n = 5) or by his bundle catheter ablation (n = 4). High energy internal shock therefore seems to be an interesting treatment in patients with permanent atrial fibrillation after failure of external electric shock. It enabled 13 of the 17 patients in this series to avoid His bundle catheter ablation indicated by the quasi-impossibility to control the atrial rate and associated symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)