Letter by Kriatselis and Roser Regarding Article, “Small or Large Isolation Areas Around the Pulmonary Veins for the Treatment of Atrial Fibrillation? Results From a Prospective Randomized Study”
To the Editor:
We read with interest the article by Arentz et al1 that compared the outcome of small and large isolation areas around the pulmonary veins. Large-area isolation was guided anatomically with ablation lesions targeted outside of the pulmonary vein ostia (>1 cm on the posterior and >5 mm on the anterior walls), whereas small-area isolation targeted ablation at the ostial position.
Mapping of the pulmonary veins for local potentials was performed sequentially with a single catheter (either a 64-pole basket catheter or a 20-pole circular mapping catheter). In our opinion, this asynchrony imposes a major limitation on the comparability of the 2 approaches. It has been shown2,3 that during inspiration, the location of the ostia of the pulmonary veins, especially of the inferior pulmonary vein, changes significantly. For that reason, delivery of radiofrequency energy at about 5 to 10 mm outside the pulmonary vein ostia, for example for 60 s, might lead to significant radiofrequency energy delivery directly at the ostial site of the pulmonary veins (eg, for an inspiration duration of about 2 s and approximately 10 inspiration/expiration cycles in 60 s, about 20 s of radiofrequency energy would be delivered). Under some circumstances, this could lead to sequential and rather ostial isolation, even if the intention was to isolate the pulmonary veins simultaneously through a large isolation line. We believe that only the combination of the anatomic approach with demonstration of simultaneous disappearance of the potentials in both ipsilateral veins, using the double Lasso technique,4 can prove large-area isolation.
Arentz T, Weber R, Bürkle G, Herrera C, Blum T, Stockinger J, Minners J, Neumann FJ, Kalusche D. Small or large isolation areas around the pulmonary veins for the treatment of atrial fibrillation? Results from a prospective randomized study. Circulation. 2007; 115: 3057–3063.
Ector J, Loeckx D, Coudijzer W, De Buck S, Maes F, Dymarkowski S, Bogaert J, Heidbüchel H. Images in cardiovascular medicine: changes in left atrial and pulmonary venous anatomy during respiration: a 4-dimensional computed tomography–based assessment and implications for atrial fibrillation ablation. Circulation. 2007; 115: e617–e619.
Ouyang F, Bänsch D, Ernst S, Schaumann S, Hachiya H, Chen M, Chun J, Falk P, Khanedani A, Antz M, Kuck KH. Complete isolation of the left atrium surrounding the pulmonary veins: new insights from the double Lasso technique in paroxysmal atrial fibrillation. Circulation. 2004; 110: 2090–2096.