Structured abstract
Background : It is established that ethanol infusion in the vein
of Marshall (EIVOM) effectively creates a linear ablation lesion in the
mitral isthmus (MI). However, data on the long-term success rates of MI
ablation remains limited.
Methods and Results : Our cohort consisted of 560 patients with
non-paroxysmal atrial fibrillation (AF) who underwent an initial MI
ablation. Ablations were performed by only radiofrequency (RF) in 384
patients (RF group) or by RF and EIVOM in 176 patients (EIVOM/RF group).
Ethanol of 5 mL was used to perform EIVOM in advance of RF. Following
EIVOM, RF pulses were delivered to the lateral MI line. Bidirectional MI
block was fully achieved in 353 (first 318, re-do 35) patients of the RF
group and 171 (first 128, re-do 43) patients of the EIVOM/RF group (p =
0.09 in the first, 0.10 in the re-do ablation cases). In cases with
complete MI line block, recurrent AF or atrial tachycardia (AT) was
observed in 130 (37%) patients of the RF group and in 64 (37%)
patients of the EIVOM/RF group (log-rank p = 0.12 in the first, 0.30 in
the re-do ablation cases). Of the total 194 patients, 112 with drug
refractory AF or AT proceeded to the subsequent ablation process.
Reconnection of MI block line was observed in 39 (49%) patients in the
RF group and 25 (58%) patients in the EIVOM/RF group (p = 0.32).
Conclusion: EIVOM effectively ensures MI line block; however, the
reconnection rate was similar between the two groups.
Keywords: atrial fibrillation; mitral isthmus; Marshall vein;
ethanol infusion; chemical ablation