Objective: As an alternative to the mitral isthmus line (MIL), the left atrial anterior wall line (LAAWL) is effective for the treatment of perimitral flutter. This study evaluated the electrophysiologic and clinical outcomes of LAAWL versus MIL in patients with persistent atrial fibrillation (AF).
Methods: Two hundred patients with persistent AF were evenly randomized to the LAAWL and MIL groups. After confirming bidirectional block of the line, left atrial appendage (LAA) activation time and LA propagation pattern were assessed during sinus rhythm (SR). Transthoracic and transesophageal echocardiography (TTE and TEE) were performed at 12 months after ablation in patients who remained in stable SR.
Results: In the 74 patients with LAAWL conduction block relative to the 79 with MIL conduction block, LA propagation contour was markedly changed with delayed LAA potential (longer P-wave onset-to-LAA potential interval: 151.7 ± 19.5 vs. 67.8 ± 18.3 milliseconds, P < 0.001); TTE peak A velocity was lower and LAA emptying wave was delayed in the LAAWL group compared with the MIL group; spontaneous echo contrast (SEC) detected in the LAAWL group was significantly higher than that in the MIL group (15.8% vs. 1.6%, p = 0.0004). During a mean follow-up period of 31.8 ± 9.4 (22-57) months, there were 5 cases of stroke in the LAAWL group, which was significantly different from the MIL group (5% vs. 0%, P = 0.047).
Conclusions: Complete linear lesions transecting the anterior LA were associated with a significant change in the SR propagation pattern with late activation of LAA. This might result in an increased risk of long-term thrombo-embolism events.
Keywords: atrial fibrillation; catheter ablation; linear ablation.
© 2015 Wiley Periodicals, Inc.