A simple maneuver to determine if septal accessory pathway ablation requires a left atrial approach

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Septal accessory pathway (AP) ablation presents anatomical challenges.
• Left atrial (LA) access is often a secondary consideration after right-sided ablation failure.
• Predictive markers for successful septal AP ablation are needed.

Purpose of the Study:

• To determine if the difference in ventriculo-atrial (VA) time during right ventricular (RV) apical pacing versus tachycardia can predict the successful ablation site of septal APs.
• To assess the utility of VA time differences in guiding the decision for LA access during septal AP ablation.

Main Methods:

• Review of intracardiac electrograms from patients with orthodromic reciprocating tachycardia (ORT) using a septal AP.
• Measurement of the difference between VA intervals during RV apical pacing and ORT (∆VA).
• Measurement of the difference in VA interval during RV entrainment and ORT (StimA-VA).

Main Results:

• Median ∆VA was significantly lower in patients ablated on the right side (12±19 ms) compared to the left side (56±10 ms).
• StimA-VA also differed significantly between groups (22±14 ms vs. 53±9 ms).
• ∆VA and StimA-VA < 40 ms predicted right-sided ablation, while > 40 ms predicted left-sided ablation for non-decremental septal APs.

Conclusions:

• ∆VA and StimA-VA values derived from RV apical pacing predict the necessity of LA access for successful septal AP ablation in ORT.
• These electrophysiological parameters can optimize ablation strategies and potentially reduce procedural time.