New onset atrial flutter termination by overdrive transoesophageal pacing: Effects of different protocols of stimulation

Aim We evaluated the effect of different stimulation protocols on atrial flutter interruption by transoesophageal pacing. Methods and Results Eighty patients with new onset atrial flutter were randomized into four groups. Pacing was attempted under the following conditions: with short bursts (5s), without treatment (group A) and after oral administration of propafenone 600mg (group B); with prolonged bursts (30s), without treatment (group C) and after oral administration of propafenone 600mg (group D). Pacing interrupted atrial flutter in 20% of patients in A, 55% in B, 50% in C and 85% in D. The use of longer bursts gave better results both in patients without treatment (P<0·05: C vs A) and in patients with propafenone (P<0·05: D vs B). Comparing groups with the same stimulation protocol, we observed a better response in patients treated with propafenone (P<0·05: B vs A and D vs C). In the groups without treatment the use of shorter bursts was associated with a lower induction of stable atrial fibrillation (three vs nine episodes), in the groups on propafenone no differences were observed (one vs one episode). Conclusions We conclude that the association of propafenone with long bursts gives the best result for interruption of new onset atrial flutter by transoesophageal pacing.