Towards durable pulmonary vein isolation: we are closing the gap: Figure 1

This editorial refers to ‘EFFICAS II: optimization of catheter contact force improves outcome of pulmonary vein isolation for paroxysmal atrial fibrillation’ by J. Kautzner et al. , doi:10.1093/europace/euv057. Pulmonary vein isolation (PVI) is simultaneously the cornerstone and Achilles heel of ablation for paroxysmal and persistent atrial fibrillation (AF).1 Radiofrequency (RF) ablation, the most widely used ablation technique, aims to achieve circumferential ipsilateral PVI by creating contiguous and transmural point-by-point lesions.2 Despite acute isolation, late PV reconnection results in AF recurrences with the ensuing need for repeat ablations, thereby putting patients at increased risk of complications and decreasing the cost-effectiveness of the procedure. Our inability to achieve durable PVI with standard irrigated catheters is related to the complexity of assessing transmurality of individual lesions based on conventional parameters such as power, time, impedance changes, electrode temperature, and changes in electrogram morphology. Assessment of lesion contiguity with fluoroscopy and 3D mapping systems is also limited. In addition, ablation-induced tissue oedema may eclipse lesions with incomplete transmurality or contiguity ensuing in gaps at a later stage.3 Not surprisingly, with standard irrigated catheters, only 65% of PV pairs are proved to be isolated after adenosine-challenge at the time of …