A randomized comparison of the straight linear approach with electrogram mapping focal approach in selective slow pathway ablation

The aim of this study was to evaluate the efficacy and safety of the anatom ic linear approach in selective A VN slow pathway ablation, in comparison t o the widely used electrogram mapping focal approach. It remains undetermin ed whether or not anatomic linear ablation has a greater potential for elim inating slow pathway conduction than does focal ablation. Fifty consecutive patients (21 men, 29 women, age 56 +/- 14 years) with common type AVNRT we re randomly assigned to the linear approach (25 patients) or local electrog ram mapping approach (25 patients). A linear lesion was created between the tricuspid annulus, at the midlevel of the coronary sinus (CS) ostium, and the anterior aspect of the CS infundibulum. In 22 (88%) patients in the lin ear group, the AVNRT was successfully eliminated by 1.5 +/-0.8 linear RF ap plications without any complications. All 25 patients in the focal group sa tisfied the endpoint criteria after 3.8 +/-2.4 focal RF deliveries. The suc cess rate did not significantly differ between the two groups. Out of the 2 2 patients with a successful outcome in the linear group, 17 (77%) attained complete abolition of the slow pathway conduction, whereas this was observ ed in only eight (32%) patients in the focal group (P < 0.005). The session time was significantly shorter in the linear group, Recurrence of the tach ycardia was not documented in any patient during a mean follow-up of 18<plu s/minus>8 months except one with residual slow pathway conduction in the fo cal ablation group. In conclusion, the anatomic linear approach can be perf ormed safely and possesses a greater potential for slow pathway interruptio n compared to the electrogram mapping focal approach.