Bow-energy internal cardioversion in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion: results and long-term follow-up

Aim Low-energy internal cardioversion is a new electrical treatment for pat ients with persistent atrial fibrillation. This paper evaluates the efficac y and safety of low-energy internal cardioversion in patients with long-las ting atrial fibrillation refractory to external electrical cardioversion, a nd the clinical outcome of such patients. Method and Results The study population consisted of 55 patients [32 male, mean age 65 +/- 10 years, 48 (87%) with underlying heart disease] with long -lasting (mean 18 +/- 34 months) atrial fibrillation in whom external cardi oversion had failed to restore sinus rhythm. Two custom-made catheters were used: one positioned in the right atrium and one in the coronary sinus or the left pulmonary artery. A standard catheter was inserted into the right ventricular apex to provide R wave synchronization. Sinus rhythm was restor ed in 52 patients (95%) with a mean defibrillating energy of 6.9 +/- 2.6 J (320 +/- 60 V). No complications were observed. During follow-up (mean 18+/ -9 months), 16 patients (31%) suffered early recurrence (less than or equal to1 week) of atrial fibrillation and 20 patients (38%) had late recurrence (>1 week; mean 3.5+/-3.6 months) of atrial fibrillation. Six patients with a late recurrence again underwent cardioversion and five of these maintain ed sinus rhythm. Therefore, a total of 21/52 patients (40%) were in sinus r hythm at the end of follow-up. No clinical difference was found between pat ients with and without recurrences. Conclusions Low-energy internal cardioversion is a useful means of restorin g sinus rhythm in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion. More than one-third of patients main tained sinus rhythm during long-term follow-up. (Europace 2001; 3: 90-95) ( C) 2001 The European Society of Cardiology.