Towards more effective techniques for catheter ablation of atrial fibrillation: to aim for electrical disconnection of pulmonary veins or not?

Abstract

This editorial refers to ‘Prevalence of pulmonary vein disconnection after anatomical ablation for atrial fibrillation: consequences of wide atrial encircling of the pulmonary veins’† by M. Hocini et al. , on page 696 The recent discovery of a dominant role played by excitable tissues within the pulmonary veins (PVs) and at the left atrium–PV junction in the initiation and possibly also the maintenance of atrial fibrillation (AF) has led investigators to develop several catheter-based strategies aimed at limiting the electrophysiological interactions between these areas and the remaining atria. Among these, two have emerged as dominant strategies in current clinical practice: one aiming at ostial segmental disconnection (OSD) of all PVs from the adjacent atrial tissue and another aiming at anatomical circumferential ablation (ACA) away from the orifice of the PVs. OSD is best accomplished with the help of a pre-shaped circumferential multi-electrode mapping catheter advanced to the orifice of the target PV while an ablation catheter is used for radiofrequency (RF) pulse delivery at the orifice of the same PV. Using this approach, RF pulses are delivered under the guidance of the circumferential electrical activation recorded from the multi-electrode mapping catheter until no propagation of atrial impulses to the PV is observed ( Figure 1A ). Ablation is repeated in each remaining PV until electrical disconnection of all PVs is achieved. OSD is commonly achieved through segmental rather than circumferential ablation at the orifice of the PVs.1 Figure 1. Schematics of the ablation designs aimed for using OSD ( A ) or ACA ( B ). The symbols (straight arrow and wavy arrow) indicate, respectively, conduction block and delayed conduction of the electrical impulses across ablation lines obtained at the end of the two ablation strategies. Note that after segmental disconnection at the ostium of each PV, electrical impulses are inhibited from entering into or … *Tel: +39 02 5277 4337; fax: +39 02 5560 3125. E-mail address : rcappato{at}libero.it