Background:
Achieving bidirectional mitral isthmus (MI) block using radiofrequency catheter ablation (RFCA) alone is challenging, and MI reconnection is common. Adjunctive vein of Marshall (VOM) ethanol infusion (VOM-Et) can facilitate acute MI block. However, little is known about its long-term success. This study sought to evaluate the impact of adjunctive VOM-Et on MI block achievement and durability compared with RFCA alone.
Methods:
Patients undergoing the first attempt of posterior MI ablation were grouped according to their MI block index strategy: adjunctive VOM-Et and RFCA alone. Rates of acute MI block and MI reconnection observed during repeat procedures were compared between the 2 groups.
Results:
The VOM-Et group consisted of 152 patients (63.8±9.4 years) undergoing adjunctive VOM-Et for MI block. The RFCA group consisted of 110 patients (60.9±9.2 years) undergoing MI ablation using RFCA alone. Acute MI block was more frequently achieved in the VOM-Et group (98.7% [150/152] versus 63.6% [70/110];
P
<0.001) with shorter RFCA duration (5.00 [3.00–7.00] versus 19.0 [13.6–22.0] minutes;
P
<0.001). Of the 220 patients with MI block achieved during the index procedure, 81 underwent a repeat procedure during follow-up (VOM-Et group: 23.3% [35/150] versus RFCA group: 65.7% [46/70], respectively;
P
<0.001). A significantly greater number of patients exhibited durable MI block in the VOM-Et group (62.9% [22/35] versus 32.6% [15/46], respectively;
P
=0.008).
Conclusions:
Beyond facilitating acute MI block, VOM-Et is associated with greater lesion durability as evidenced by higher rates of MI block during repeat procedures.
Incidence, electrophysiological characteristics, and long‐term follow‐up of perimitral atrial flutter in patients with previously confirmed mitral isthmus block