Author + information
- Received January 7, 1992
- Revision received June 12, 1992
- Accepted July 20, 1992
- Published online February 1, 1993.
- Raul D. Mitrani, MD,
- Lawrence S. Klein, MD, FACC,
- F.Kevin Hackett, MD,
- Douglas P. Zipes, MD, FACC and
- William M. Miles, MD, FACC∗
- ↵∗Address for correspondence: William M. Miles, MD, Krannert Institute of Cardiology. 1111 West 10th Street. Indiananolis. Indiana 46202-4800.
Objectives. We compared the electrophysiologic effects on atrioventricular (AV) node physiology of selective “fast” versus selective “stow” pathway radiofrequency ablation in 42 patients with drug-resistant AV node reentrant tachycardia who underwent 51 ablation attempts to prevent tachycardia recurrence while preserving AV conduction.
Background. The recent introduction of radiofrequency ablation to treat AV node reentrant tachycardia allows the opportunity to study the effects of selective elimination of the different limbs involved in AV node reentrant tachycardia.
Methods. Selective fast pathway ablation was attempted in 13 patients by delivering radiofrequency energy anteriorly across the tricuspid valve anulus. Selective slow pathway ablation was attempted in 29 patients by delivering radiofrequency energy posteriorly across the tricuspid valve anulus at sites where putative slow pathway potentials were recorded.
Results. Selective fast pathway ablation eliminated AV node reentrant tachycardia without AV block in 6 (46%) of 13 patients after one ablation session and in an additional 3 patients (69% of total) after repeat ablation sessions. Slow pathway ablation eliminated AV node reentrant tachycardia without AV block in 26 (90%) of 29 patients after one radiofrequency ablation session and in an additional 2 patients (97% of total) after repeat ablation sessions. Selective fast pathway ablation increased the PR interval (140 to 220 ms, p = 0.0001) and AH interval (66 to 153 ms, p = 0.0001), whereas slow pathway ablation did not change these intervals. Fast pathway radiofrequency ablation caused retrograde block in 7 (64%) of 11 patients, whereas no patients undergoing slow pathway ablation developed selective retrograde block. Single AV node echo beats were commonly induced after slow but not fast pathway ablation (17 of 29 patients vs. 1 of 11 patients, respectively, p = 0.01) and did not predict recurrence of AV node reentrant tachycardia.
Conclusions. Successful selective radiofrequency ablation of fast or slow pathways in patients with AV node reentrant tachycardia resulted in different eletrophysiologic properties after ablation. Slow pathway ablation produced more successful outcomes, with a decreased prevalence of recurrent AV node reentrant tachycardia or AV block.
☆ This study was supported in part by the Herman C. Krannert Fund, Indianapolis and Grants HL-43270 and HL-07182 from the National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Public Health Service, Bethesda. Maryland and the American Heart Association, Indiana Affiliate, Indianapolis.
- Received January 7, 1992.
- Revision received June 12, 1992.
- Accepted July 20, 1992.