During a hybrid procedure, provocative pacing maneuvers and mapping techniques are performed from the endocardial side. In our series, in 23% of patients

we were not able to completely create a box lesion, even after identification of remaining gaps and repeating epicardial ablation. In these patients all pulmonary veins were isolated (bipolar bidirectional clamping), but the gaps were found in the connecting lesions at the roof or inferior line (bipolar unidirectional linear pen). To create contiguous transmural lesions in these areas, we had to apply endocardial unipolar radiofrequency energy. Since the connecting lesions are created Inhibitors,research,lifescience,medical with a non-PD0325901 clamping device, epicardial fat, tissue thickness, and the heat-sink effect are still a concern. Krul et al. described a series of 31 patients with atrial fibrillation that were treated with thoracoscopic Inhibitors,research,lifescience,medical pulmonary vein isolation and ganglionated plexus ablation.19 In patients with non-paroxysmal atrial fibrillation, left atrial ablation lines were created and conduction block verified epicardially Inhibitors,research,lifescience,medical with custom-made catheters. After 1 year, they reported

comparable success rates to our series (86% of patients had no recurrence and were off antiarrhythmic drugs) but had a significantly higher complication rate. Three patients had a sternotomy because of uncontrolled bleeding during thoracoscopic surgery. An important conceptual difference between both studies is that Krul et al. could only perform epicardial lesions without the possibility Inhibitors,research,lifescience,medical of add-on endocardial lesions, including endocardial touch-ups to improve transmurality, as well as performing cavo-tricuspid isthmus and left-sided mitral isthmus ablation. In addition, they could only check completeness of ablation

lesions from the epicardium, which with current technology may be insufficient to show complete electrical block. In these small patient groups it is difficult to make hard conclusions Inhibitors,research,lifescience,medical when comparing two studies. However, more than half of the patients in Krul’s study had paroxysmal atrial fibrillation and all patients had 24-hour Holter monitoring after 1year. In our series most patients had persistent or long-lasting persistent atrial fibrillation and had 7-day Holter monitoring at 1 year. WHAT IS THE FUTURE OF HYBRID PROCEDURES FOR THE ABLATION OF ATRIAL FIBRILLATION? Even in the best and most experienced the hands, stand-alone catheter ablations for the treatment of atrial fibrillation have a significant recurrence rate, even after initial complete pulmonary vein isolation. The need for one or possibly more repeat interventions to achieve long-term cure of atrial fibrillation is not cost-effective and increases the potential complication rate to patients unnecessarily. The majority of patients prefer a single procedure if this can be achieved safely and with minimal invasiveness.