2. Follow-up:
Recurrence: For patients with acute termination, the 1-year
recurrence-free survival rate was 58.9% (95% CI 53.5%, 64.9%). For
patients without acute termination, the 1-year recurrence-free survival
rate was 49.0% (95% CI 37.9%, 63.4%). During the study, 58.4% had
recurrent arrhythmic symptoms following ablation, not including the
immediate blanking phase (90-day period). Index arrhythmia was
terminated in most patients, but significant recurrent other atrial
arrhythmias were noticed. AAFL is the most common form of arrhythmic
recurrence, followed by AF. As the recurrence was assessed only by
surface recording, it is difficult to discern whether it is due to the
original or new arrhythmia mimicking the pattern. Based on the
replication of morphology from pre-procedural flutter tracings, the
recurrence of the targeted flutter is extremely low (2.7%). Ongoing
follow-up beyond 1-year showed higher rates of recurrences. Recurrence
is not due to recently ablated AAFL is the other useful finding.
Recurrences of new arrhythmia suggest progressive substrate changes from
the native disease or additional new substrate due to the ablation.
Utilizing linear lines to connect to electrically inert or anatomical
barriers may influence the recurrence rate. Any non-transmural lesion in
a linear line can become a substrate for reentrant arrhythmia. Assessing
the block across a linear line is operator-dependent. Most of the block
across a linear line was confirmed with a multipolar catheter time delay
and or activation reversals. After the procedure, recovery of conduction
across the line may contribute to recurrence.
Management of recurrent arrhythmias: The recurrences were
managed by anti-arrhythmic drugs, electrical cardioversion, repeat
ablation, or as the final resort, AV-node ablation. Repeat ablation was
required in 35% of the cases. AV-Nodal ablation is the last resort in
some patients (14.6%) who failed to achieve sinus rhythm despite the
flutter ablation. Achieving sinus rhythm was difficult in a small number
of patients, and they were counseled to accept that the arrhythmia was
likely their new normal if the rate was under control.