Rapid atrial pacing: a useful technique during slow pathway ablation

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Catheter ablation is a highly successful treatment for AVNRT, with success rates of 95-98%.
• Junctional rhythm during radiofrequency (RF) ablation of the slow pathway is a marker for successful AVNRT ablation.
• Ventriculoatrial (VA) conduction during junctional rhythm is an unreliable marker for antegrade AVN function, potentially risking AVN injury.

Purpose of the Study:

• To describe a technique ensuring normal antegrade AVN function during junctional rhythm in RF catheter ablation of the slow pathway.
• To evaluate the safety and efficacy of rapid atrial pacing (RAP) for preserving AVN function during AVNRT ablation.

Main Methods:

• Retrospective review of patients under 21 undergoing RF ablation for AVNRT (January 2002 - July 2005).
• RAP was performed immediately after demonstrating junctional rhythm during RF applications to assess antegrade AVN function.
• Postablation testing evaluated AVN function and tachycardia inducibility.

Main Results:

• Fifty-eight patients underwent ablation; 96% (56/58) achieved acute success.
• No patients experienced transient or permanent AVN block with RAP during junctional rhythm.
• Postablation, the Wenckebach cycle length decreased significantly (P < 0.01), indicating preserved AVN function.

Conclusions:

• Rapid atrial pacing (RAP) during RF ablation of the slow pathway is a safe method to ensure normal antegrade AVN function.
• This technique provides a reliable alternative to VA conduction assessment for preserving AVN function post-ablation.