The central controversy surrounding the interventional-surgical treatment of atrial fibrillation.

doi:10.1016/j.jtcvs.2004.08.049 I n this issue of the Journal, Fasol and colleagues from Vienna describe their technique for ablating atrial fibrillation in association with mitral valve surgery by creating a triangular pattern of lesions endocardially in the left atrium using irrigated unipolar radiofrequency. The triangular lesion pattern is described in the text as encompassing the orifices of the 4 pulmonary veins, with one corner of the triangle extending down to the mitral valve annulus. However, in Figure 1 the triangle does not include the orifices of the right pulmonary veins. In addition, in the legend for Figure 1, the authors state that the triangle also encompasses the closed orifice of the unresected left atrial appendage, although the figure itself clearly shows the closed appendage orifice to be outside the confines of the triangle. Thus, it is unclear where the triangle is located from reading the text and then observing Figure 1. Nevertheless, assuming that the triangle encompasses all 4 pulmonary vein orifices, regardless of whether it includes the closed orifice of the left atrial appendage, this lesion pattern is clearly simpler than that of the classic maze procedure, as the authors correctly state. However, several questions are left unanswered by the authors that affect the potential significance of their study. The 10 patients in this study are described as having had “chronic atrial fibrillation.” Other than noting that the atrial fibrillation had been “. . . preexisting for longer than 6 months,” the authors do not clarify whether the term “chronic” refers to the duration of the arrhythmia or to the fact that it was continuously present in these patients. If “chronic” refers to the duration of the arrhythmia, and the patients were not in continuous atrial fibrillation, they were, by definition, having recurrent bouts of paroxysmal (intermittent) atrial fibrillation. In that case the authors had up to a 90% chance of curing the atrial fibrillation by means of pulmonary vein isolation alone, assuming that all of their lesions were transmural, because the individual episodes of atrial fibrillation are dependent on an induction trigger that is located within one or more of the pulmonary veins in as many as 90% of such patients. In that case the 80% cure rate in this study would be about what is expected. If, on the other hand, the authors are using the term “chronic” in the traditional sense when applied to atrial fibrillation (ie, that the patients were in atrial fibrillation all of the time), then the 80% cure rate attained by the authors is better than expected. Because this success rate in patients with continuous atrial fibrillation cannot be attained with simple pulmonary vein isolation alone, it would confirm the importance of extending the triangle from the pulmonary veins down to the mitral annulus, a point that I have emphasized in the past. Perhaps the greatest importance of this article from the Vienna group is that it once again emphasizes the importance of describing the preoperative diagnosis accurately to interpret the results properly. This is the basis of the majority of the confusion that currently exists in the field of atrial fibrillation therapy. During the