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INTRODUCTION Intraoperative radiofrequency (RF) ablation is an effective treatment of atrial fibrillation (AF). However, secondary arrhythmias late after ablation may complicate the patient's course. We report on the incidence, mechanisms, and treatment of gap-related atrial flutter and other secondary arrhythmias during long-term follow-up. METHODS AND RESULTS In 129 patients who underwent intraoperative RF ablation with placement of left atrial linear lesions using minimally invasive surgical techniques, secondary arrhythmias were analyzed during long-term follow-up (20 +/- 6 months). Transient atrial arrhythmias during the first 3 postoperative months were excluded. In 8 (6.2%) of 129 patients, sustained stable secondary arrhythmias were documented. Left atrial, gap-related atrial flutter was observed in 4 patients (3.1%). The flutter was treated by percutaneous RF ablation in 3 patients (2.3%) and with drugs in 1 patient (0.8%). In 2 patients (1.6%), right atrial isthmus-dependent atrial flutter occurred and was treated successfully by percutaneous RF ablation. In 2 patients (1.6%), ectopic right atrial tachycardias occurred and were treated with percutaneous RF ablation. CONCLUSION Late after intraoperative RF ablation of atrial fibrillation, three types of stable secondary arrhythmias were observed in 6% of patients: left atrial gap-related atrial flutter, right atrial isthmus-dependent atrial flutter, and ectopic atrial tachycardia. Gaps after intraoperative RF ablation due to noncontinuous or nontransmural linear lesions may lead to stable left atrial macroreentrant tachycardias, requiring new interventional therapy.

Introduction: The aim of this study was to describe the arrhythmogenic substrate in postinfarction patients with ventricular tachycardia (VT) guiding the placement of individual strategic linear lesions transecting all potential isthmuses using target area maps with limited mapping points to allow short procedure times. Methods and Results: In 28 patients with pleomorphic, unstable, and/or incessant VT, electroanatomic voltage mapping was performed in conjunction with limited sinus rhythm mapping, pace mapping, and activation mapping. Radiofrequency (RF) energy was applied directly within the low-voltage areas of the chronically infarcted areas or in the border zone. Ablation lines typically were perpendicular to the course of the presumed central common pathways. The maps consisted of 63 ± 30 mapping points. An average lesion line length of 46 ± 21 mm was placed with 17 ± 7 RF pulses. Twenty-two (79%) of the 28 patients were rendered completely noninducible at the end of the procedure. Procedure time measured 134 ± 41 minutes. No major complications were observed. Six (27%) of 22 patients who were rendered completely noninducible experienced VT recurrence during follow-up versus 4 (67%) of 6 patients who were still inducible after ablation (P = 0.06). Conclusion: Individually tailored substrate description guiding the placement of linear lesion lines transecting potential isthmuses rendered 80% of the patients completely noninducible. The construction of regional target area maps allowed short procedure times, with a resulting low incidence of complications in these critically ill patients. (J Cardiovasc Electrophysiol, Vol. 14, pp. 675-681, July 2003)

UNLABELLED Topography of the esophagus in atrial fibrillation ablation. INTRODUCTION The close anatomic relationship of the posterior wall of the left atrium (LA) and the thermosensitive esophagus creates a potential hazard in catheter ablation procedures. METHODS AND RESULTS In 30 patients (pts) with atrial fibrillation (AF) undergoing catheter ablation, we prospectively studied the course and contact of the esophagus in relation to LA and the topographic proximity to ablation lines encircling the right-sided and left-sided pulmonary veins (PV) as well as to the posterior line connecting the encircling lines using the electromagnetic mapping system for reconstruction of LA and for tagging of the esophagus. This new technique of anatomic tagging of the esophagus was validated against the CT scan as a standard imaging procedure. The esophageal course was highly variable, extending from courses in direct vicinity to the left- or right-sided PV as well as in the midportion of the posterior LA. In order to avoid energy application in direct proximity to the esophagus, adjustments of the left and right PV encircling lines were necessary in 14/30 pts (47%) and 3/30 (10%). In 30 pts (100%), the mid- to inferior areas of the posterior LA revealed contact with the esophagus. Therefore, posterior and inferior linear ablation lines were abandoned and shifted to superior in 29 pts (97%). CONCLUSIONS Anatomic tagging of esophagus revealed a highly variable proximity to different areas of the posterior LA suggesting individual adjustment of encircling and linear ablation lines in AF ablation procedures to avoid the life threatening complication of esophagus perforation.