Clinical feasibility of low energy internal atrial cardioversion with a three-electrode configuration in patients with unsuccessful conventional configurations

Low energy internal cardioversion is a safe and highly effective method for atrial fibrillation termination. We will describe 6 patients in whom the c onventional 2-electrode systems with the defibrillation leads positioned in the right atrium and in the coronary sinus or left pulmonary artery failed to terminate the arrhythmia despite the use of maximal available energies. A 3-electrode configuration including right atrium, coronary sinus and lef t pulmonary artery was used in order to encompass as much atrial mass as po ssible between the cathode and the anode. The atrial fibrillation was succe ssfully interrupted in 4 out of 6 patients. The creation of a 3-electrode c onfiguration may be a further technical expedient in order to increase the success rate of internal cardioversion when usual manoeuvres like lead repo sitioning, reversion of polarity, or addition of antiarrhythmic drugs are i neffective.