Coronary microcatheter mapping of coronary arteries during radiofrequency ablation in children

Epicardial Ablation via Arterial and Venous Systems

The intracoronary artery and venous routes provide unique roadmaps for mapping and interventions for ventricular arrhythmias and certain atrial arrhythmias. The unique anatomic location of these vessels on the epicardial surface enables mapping/interventions without the need to access the pericardial space. These anatomic routes also track deep into certain intramural regions, with interventions that are not accessible from either epicardial or endocardial routes. To map smaller vessels, multipolar catheters and wires are used to record local electrograms. Endocardial/epicardial ablation at adjacent sites is sometimes required to enhance successful outcomes. This article describes tools, techniques, and site-specific mapping and interventions.

A subvalvular catheter approach for radiofrequency ablation of right-sided accessory pathways

BACKGROUND

Conventional catheter ablation of right-sided accessory pathways (RAPs) can be challenging.

OBJECTIVE

To determine if a subvalvular catheter approach for RAPs targeting the ventricular insertion site, as on the left side, can improve catheter stability and tissue contact and thus increase acute and chronic ablation success rates.

METHODS AND RESULTS

We retrospectively compared 22 patients (pts) with conventional catheter ablation of RAPs (group 1) with 9 consecutive pts (group 2) undergoing catheter ablation of a RAP using a subvalvular catheter approach targeting the ventricular site of AP. Ablation failed in 2/22 group 1 vs 0/9 group 2 pts (ns) and recurrences of AP conduction were registered in 4/19 group 1 vs 1/9 group 2 pts (ns) during follow-up. Significant shorter values were found in group 2 pts compared with group 1 for number of RF applications (3.6 ± 1.6 vs 8.2 ± 4.3), AP block time (6.2 ± 2.4 vs 9.2 ± 3.9 min), fluoroscopy time (17.2 ± 6.9 vs 25.6 ± 10.3 min), and procedure time (70.8 ± 23.9 vs 138 ± 44.4 min). There were no procedure related complications.

CONCLUSION

Catheter ablation of RAPs using a subvalvular approach seems as effective and safe compared with conventional ablation but with reduced procedure time and radiation exposure and might be at least considered an alternative after failed conventional catheter ablation of RAPs.