METHODS
Consecutive patients undergoing CTI ablation in the absence of any other
ablation target received a bolus injection of adenosine 10mg via a
femoral venous access sheath at 5 minutes after the apparent achievement
of persistent bidirectional CTI block. All patients were treated by the
same operators in 2 centres. All procedures were performed under local
anaesthesia using right femoral venous access and using fluoroscopic
guidance to place a deflectable diagnostic catheter in the coronary
sinus and a multipolar catheter in the lateral right atrium. A Blazer
large-curve 8mm or 10mm tip ablation catheter was used to create a line
of lesions to block the CTI and to perform consolidating lesions to
create a clear zone of abolition of local electrograms.
After achievement of satisfactory CTI block, a waiting period was
commenced. At 5 minutes into the waiting period, intravenous adenosine
10mg was administered centrally. The patient observations were
monitored, the surface electrocardiogram and intra-cardiac electrograms
were assessed for both evidence of adenosine-induced AV block and for
transient re-conduction of the CTI. Further RF ablation was performed
for all those who had persistent CTI conduction recurrence. For all
those who required re-ablation to achieve enduring CTI line block, a
full waiting period was respected, with no re-testing with adenosine.