Achieving left lateral isthmus block during ablation for nonparoxysmal atrial fibrillation did not significantly affect recurrences after 3 months compared to failed block (17.7% vs 10.5%, P=NS).
Observational (n=54)
Does complete conduction block of the left lateral isthmus improve clinical outcomes in patients with nonparoxysmal atrial fibrillation?
Achieving complete conduction block of the left lateral isthmus is more difficult in patients with a longer vein of Marshall and does not appear to improve short-term clinical outcomes in nonparoxysmal atrial fibrillation.
Absolute Event Rate: 17.7% vs 10.5%
p-value: p=NS
BACKGROUND: The vein of Marshall (VOM), which exists along the left lateral isthmus (LLI), constitutes a muscular connection between the coronary sinus (CS) and the left atrium (LA). We hypothesized that anatomical variation of the VOM affects the bidirectional block of LLI and the clinical outcome in patients with nonparoxysmal atrial fibrillation (NPAF). METHODS: Among 73 patients with NPAF, 54 patients (47 male, 54.1 +/- 10.4 years old) with a clearly visible VOM (74.0%) were included. After circumferential antral ablation, double linear endocardial ablation of LLI was performed along the VOM. Unless LLI block was achievable by endocardial ablation, the ablation was performed inside the CS. RESULTS: LLI block was achievable in 35 patients (64.8%; 11.1% by endocardial ablation vs 53.7% by additional inside CS ablation; P < 0.01). In patients with failed LLI block, the VOM was significantly longer (P < 0.05) on the right anterior oblique (RAO) view than in those with successful LLI block. LA volume or LLI length measured by CT image were not different (P = NS). During 11.4 +/- 5.0 months follow-up, early recurrences within 3 months (47.4% vs 28.6%, P = NS) and recurrences after 3 months (10.5% vs 17.7%, P = NS) were not different with or without LLI block. CONCLUSION: LLI block, which is more difficult to achieve in patients with a longer VOM, was achievable in 65% of patients with NPAF by linear ablation along the VOM and additional inside CS ablation, but did not affect the short-term clinical outcome.
Choi et al. (Fri,) conducted a observational in Nonparoxysmal atrial fibrillation (n=54). Left lateral isthmus (LLI) block via linear endocardial and inside coronary sinus ablation vs. Failed LLI block was evaluated on Recurrences after 3 months (p=NS). Achieving left lateral isthmus block during ablation for nonparoxysmal atrial fibrillation did not significantly affect recurrences after 3 months compared to failed block (17.7% vs 10.5%, P=NS).