Simultaneous noncontact mapping of left atrium in patients with paroxysmalatrial fibrillation

Background - Catheter ablation of pulmonary vein ectopic foci is a potentia lly curative treatment strategy for patients with atrial fibrillation. Howe ver, identification of arrhythmogenic pulmonary veins with conventional map ping is difficult, especially in patients with rare focal activity, multipl e active foci, or extrapulmonary foci. The present study was designed to in vestigate use of simultaneous noncontact mapping in this setting. Methods and Results - In 17 consecutive patients with paroxysmal atrial fib rillation, a catheter-mounted noncontact multielectrode array positioned in the left atrium was used to reconstruct 3300 electrograms simultaneously f rom a single beat. Isopotential maps were generated during sinus rhythm and focal activity. After ectopic foci were identified, radiofrequency cathete r ablation was performed in patients with 1 or 2 foci. However, in patients who had multiple foci, intraoperative ablation of atrial fibrillation was advised. A total of 28 ectopic foci (25 pulmonary vein foci and 3 extrapulm onary vein foci) were identified by use of isopotential maps generated from a single beat of focal activity. Radiofrequency catheter ablation guided b y noncontact mapping was attempted in 12 patients with 1 or 2 ectopic foci. Successful ablation of atrial fibrillation was achieved in 9 of 12 patient s (75%). Conclusions - Noncontact mapping allows rapid and precise identification of arrhythmogenic pulmonary veins in addition to extrapulmonary vein foci. Th us, the present study shows that the technology may be used not only to gui de radiofrequency catheter ablation, but also as a diagnostic tool to devel op individual treatment strategies.