How to perform pulmonary vein isolation

The advent of technology for the delivery of radiofrequency energy via electrode catheters, in the late 1980s, led to the perfection of techniques for the ablation of accessory pathways and classical flutter 1–4. This has been so successful that these substrates for arrhythmia are rarely seen in the Western world. Two major arrhythmias, however, still remain to be conquered—atrial fibrillation and ventricular tachycardia/fibrillation. The occurrence of atrial fibrillation (AF) seems to be dependent on a number of factors 5. In most situations there is some form of underlying atrial substrate, which is usually the presence of intra-atrial conduction delay. In addition, initiating factors for AF are required and the commonest of these appear to be atrial ectopic beats 6. The major sources of these ectopic beats appear to be the pulmonary veins 7, although extrapulmonary vein sources are being increasingly reported 8,9. Numerous recent studies suggest that AF may be treated by the techniques based on ablation within or around the pulmonary veins. Initial reports were based on the identification of pulmonary vein ectopic foci and the abolition of these sources 10. The difficulties of making pulmonary foci fire and thereby identifying the culprit vein 11 led to the approach of attempting to achieve electrical isolation of all four pulmonary veins in the hope of abolishing the initiating triggers 12. The recent results reported by Haissaguerre's group suggest that around 70% of patients with paroxysmal atrial fibrillation in normal hearts, can be made to hold long-term sinus rhythm by means of this technique 12,13. Most patients have four pulmonary veins, two on the left and two on the right (Fig. 1). Many patients will have veins on the right or left side merging to a common ostium before entering …