Author + information
- Received May 1, 1992
- Revision received January 27, 1993
- Accepted February 4, 1993
- Published online August 1, 1993.
- Yaver Bashir, MRCP∗,
- Spencer C. Heald, FRACP,
- Sean O'nunain, MRCP,
- Demosthenes Katritsis, MD, PhD,
- A.John Camm, MD, FACC and
- David E. Ward, MD, FRCP
- ↵∗Address for correspondence:Yaver Bashir, MRCP, Department of Cardiological Sciences, Saint George's Hospital Medical School, Cranmer Terrace, London SW17 ORE England, United Kingdom
Objectives. This report describes a novel technique for ablation of “difficult” posteroseptal pathways.
Background. Although radiofrequency ablation of accessory atrioventricular (AV) pathways is successful in ≥ 90% of cases, particular difficulty may be encountered with some bypass tracts in the posterostptal region.
Methods. In eight ptients with posteroseptal accessory pathways (two concealed), radiofrequency catheter ablation using conventional unipolar current applications from favorable sites along the tricuspid or mitral annulus, or both, was unsuccessful Subsequently, a bipolar technique was adopted, with current application between the distal electrodes of two catheters positioned against the septal region at sites of early activation along both mitral and tricuspid annuli.
Results. The bipolar configuration proved effective in all cases. The number of bipolar lesions required for success was one (five ptients), five (two patients) and nine (one patient). In five patients, bipolar current application abolished pathway conduction using positions at which delivery of unipolar lesions had been ineffective or caused transient block. The AV or ventriculoatrial interval at successful sites varied from 20 to 65 ms, and the time from delta wave onset to local ventricular activation was zero or negative. There were no complications attributable to the bipolar technique. During follow-up of 8 to 36 weeks, pathway conduction has not recurred in any ptient.
Conclusions. Bipolar radiofrequency current delivery across the septal region using a tricuspid annulus-mitral annulus electrode configuration may abolish accessory pathway conduction when conventional unipoler applications have proved ineffective. The technique may reduce procedure duration, radiation exposure and overall failure rate in these problematic cases.
- Received May 1, 1992.
- Revision received January 27, 1993.
- Accepted February 4, 1993.