DISCUSSION:
Typical AVNRT is the most common cause for SVT and slow pathway ablation provides long term cure in > 95% of patients. To date there is a paucity of prospective studies evaluating the acute impact of catheter ablation in the region of the slow pathway on inducibility of AVNRT. Prior retrospective studies exploring the characteristics of JR have reported variable outcomes on slow pathway conduction26, 37, 38. In the present study we prospectively evaluated the impact of each individual radiofrequency application on slow pathway conduction. The main findings were:
  1. Junctional rhythm was required during RFA for successful slow pathway ablation in all;
  2. The median cycle length of junctional rhythm was similar during effective and ineffective RF applications (587 ± 150 vs 611 ± 193 p = 0.4);
  3. Junctional atrial (JA) block during faster junctional rhythm was associated with a high likelihood of successful slow pathway modification and;
  4. RF applications as short as 5-10 seconds can result in successful modification of the slow pathway.