Is isolation of all four pulmonary veins necessary in patients with paroxysmal atrial fibrillation?

The upper pulmonary veins (PVs) are responsible for the majority of atrial fibrillation (AF) triggering foci, whereas the inferior PVs are more difficult to ablate and prone to postablation ostial stenosis. Most procedure failures can be attributed to incomplete isolation or recurrent PV left atrial reconnection rather than to identification of another focus. Furthermore, in certain patients AF triggers can be detected outside the PVs, and local denervation of the ganglionic plexus around the superior PV left atrial junctions following the ablation procedure may also play a role in eliminating AF. Based on these data, the authors propose that in AF patients the superior PVs should be ablated first, and in case of recurrence a second procedure should be performed for identification of PV left atrial reconnection or extrapulmonary foci and additional ablation of the inferior PVs. Such a staged approach might offer slightly lower success rates but with a significantly lower radiation exposure and procedural time and at a smaller risk of ablation induced PV stenosis.