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Surface Electrocardiographic Patterns and Electrophysiologic Characteristics of Atrial Flutter Following Modified Radiofrequency MAZE Procedures
Author(s) -
AKAR JOSEPH G.,
ALCHEKAKIE M. OBADAH,
HAI AFROZ,
BRYSIEWICZ NEIL,
PORTER MICHAEL,
VARMA NIRAJ,
SANTUCCI PETER,
WILBER DAVID J.
Publication year - 2007
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.2007.00761.x
Subject(s) - medicine , atrial flutter , cardiology , atrial fibrillation , radiofrequency ablation , ablation , electrophysiology , electrocardiography , catheter ablation , anesthesia
The radiofrequency MAZE is becoming a common adjunct to cardiac surgery in patients with atrial fibrillation. While a variety of postoperative arrhythmias have been described following the original Cox‐MAZE III procedure, the electrophysiological characteristics and surgical substrate of post‐radiofrequency MAZE flutter have not been correlated. We sought to determine the location, ECG patterns, and electrophysiological characteristics of post‐radiofrequency MAZE atrial flutter. Methods: Nine consecutive patients with post‐radiofrequency MAZE flutter presented for catheter ablation 9 ± 10 months after surgery. Results: Only one patient (11%) had an ECG appearance consistent with typical isthmus‐dependent right atrial (RA) flutter. However, on electrophysiological study, 3/9 patients (33%) had typical right counter‐clockwise flutter entrained from the cavo‐tricuspid isthmus, despite description of surgical isthmus ablation. Six patients (67%) had left atrial (LA) circuits. These involved the mitral annulus in 5/6 cases (83%) despite description of surgical mitral isthmus ablation in the majority (60%). LA flutters had a shorter cycle length compared with RA flutters (253 ± 39 msec and 332 ± 63 msec respectively, P < 0.05). After a mean of 8 ± 4 months following ablation, 8/9 patients (89%) were in sinus rhythm. Conclusion: Up to one‐third of post‐radiofrequency MAZE circuits are typical isthmus‐dependent RA flutters, despite a highly atypical surface ECG morphology. Therefore, diagnostic electrophysiological studies should commence with entrainment at the cavo‐tricuspid isthmus in order to exclude typical flutter, regardless of the surface ECG appearance. Incomplete surgical lesions at the mitral and cavo‐tricuspid isthmus likely predispose to the development of post‐radiofrequency MAZE flutter.