eComment. Bipolar radiofrequency ablation for atrial fibrillation during concomitant cardiac surgery

Structural heart disease is very often accompanied by atrial fibrillation (AF) and can worsen the patient's condition perioperatively by haemodynamic inadequacy and low cardiac output. Since its introduction in 1987 by James Cox, the surgical maze procedure became a “gold standard” in terms of restoration of sinus rhythm. Efforts to reduce surgical risk brought about new approaches to the problem with the use of different types of energy to perform transmural and linear lesions in the atria. Bipolar radiofrequency ablation is most effective in this respect according to data in the literature [1]. Within the period May 2010 to May 2012, 63 patients with concomitant heart pathology underwent bipolar radiofrequency ablation using the AtriCure system (West Chester, OH, USA) due to persistent or long-standing persistent AF. Besides AF, other pathologies were treated: three left atrial myxomas, 12 mitral valve annuloplasties, 41 mitral valve replacements, and seven aortic valve replacements. In all 63 cases, the maze IV procedure was performed without significant influence on intervention and cross-clamping times (mean time of additional surgical ablation was 18 ± 3 minutes). During the acute period after surgery, no major surgical complications were observed. Two patients (3%) required dual-chamber pacemaker implantation because of sick sinus syndrome. All patients received amiodarone, if tolerated, or sotalol perioperatively and after discharge as the main anti-arrhythmic drug. The postablative atrial tachycardia (PAAT) rate was assessed using repetitive 4-hour Holter monitoring at 3 (after blanking period), 6, 12, 18 and 24 months respectively. Paroxysm was considered significant if lasting more than 30 seconds. At 2-year follow up, most recurrences of PAAT were observed from 6 to 12 months after surgery (14-16 %); from 12 to 24 months we observed a 12% recurrence rate. Basi et. al. [1] include a strong statement arising from their meta-analysis that bipolar RFA is highly successful in restoring sinus rhythm and, as a result, improving heart failure [2]. There is also clear evidence that additional surgical ablation does not significantly affect postoperative morbidity and mortality and has an advantage in terms of transmurality and cost-effectiveness versus unipolar ablation and other sources of energy [3]. According to our data, bipolar RFA has a short learning curve, is simple to use in the operating theatre and is effective. It can be used in any case of concomitant heart surgery. In some cases, such as isolated AF refractory to antiarrhythmic drugs and multiple percutaneous attempts, bipolar RFA can also be recommended to patients through thoracotomy or thoracoscopy.

Conflict of Interest: None declared