3.4 Arrhythmia recurrences and details of the redo procedures
After the index procedure which included MI ablation, a redo procedure
was required in 9 patients. The AF/AT free survival rate, in a mean
follow-up period of 22.2±8.1 months, was 66.7% (48/72 patients) and
77.8% (56/72 patients) after the index MI ablation procedure and the
supplementary redo procedure, respectively. Particularly, in patients
with AT, the event-free survival rate was 71.9% (23/32 patients) and
87.5% (28/32 patients) after the index and the redo procedure,
respectively, while patients with AF had 62.5% (25/40 patients) and
70% (28/40 patients) event-free survival rate after the index and the
redo procedure, respectively. Patients with AT appeared to have a
significantly better prognosis in maintaining SR after MI ablation than
patients with AF (log-rank, P=0.0466) (Figure 7 ). However,
87.5% of patients with AT had previously undergone LA ablation compared
to 22.5% of patients with AF. Of the 4 patients who had unsuccessful MI
ablation at the initial procedure, one who relapsed with PMF has
undergone re-ablation with successful completion of MI and since then he
is in SR, while of the other three, two had AF recurrence and underwent
rate control therapy and one remained in SR. Among patients with PMF and
MI pseudo-block, only one recurred with a brief episode of paroxysmal AF
18 months after the index MI ablation procedure.
After the successful MI ablation, 9 patients underwent a redo procedure
due to AT/AF recurrence. In 8 / 9 (88.9%) the pacing proof of MI block
was maintained. In one of the 9 patients the MI conduction had overtly
recurred, and in 2 patients MI pseudo-block was confirmed, as the pacing
criteria of MI block were fulfilled in parallel with the occurrence of
PMF. The PMF was successfully treated by ablating the gap in MI.
Thirty-seven patients who underwent MI ablation had previous AF ablation
(33 one procedure, and 4 two procedures, 1.1 procedures / patient).
During the MI ablation procedure, PV reconnection was found in 27/37
(73%) patients with at least 1 PV reconnected and in 66/148 (44.6%) of
the re-evaluated PVs.