Limitations
We encountered several limitations in this study. First, this is a
retrospective, single-center study. Therefore, it was not randomized.
EIVOM was performed in all cases with the amenable VOM as often as
possible. Second, the ablation strategy was changed during the research
period. During a certain period, linear ablation for the left atrial
bottom line was performed less than for the roof line. Therefore, a
significant difference was observed between the two groups regarding the
bottom line ablation. Third, a total of 23 patients were not followed
because of personal reasons. It might have had an effect on the result
of the AF/AT- free survival rate. Fourth, the right PV and bottom line
reconnections were significantly higher in the EIVOM/RF group than in
the RF group. It was possible that these differences had a distinct
impact on the AF/AT- free survival rate. Fifth, as was previously
mentioned, we determined the first re-ablation site according to the
information on the electrogram sequences recorded inside the CS. If we
achieved an MI line block through EIVOM or RF ablations in the CS, we
would determine that reconnection existed only in the epicardium.
However, both EIVOM and RF ablations were possible in the development of
a transmural lesion. Sixth, it was impossible to evaluate the pure
effect of EIVOM in the subsequent ablation session, because the MI area
was already ablated by RF in the first session. Finally, the
reconnection rates shown in Table 3 occurred only in AF recurrence or AT
cases, which went into a subsequent ablation session. The true
reconnection rate was limited due to MI durability when the success
cases were unidentified.