High output pace mapping on the right coronary cusp to avoid atrioventricular conduction injury in a patient with an RCC-ventricular arrhythmia
H Hachiya, S Hara, N Miwa, Y Sato, S KusaAbstract
Background
Atrioventricular conduction (AVC) injury occurred transiently during RF at a site without a His bundle electrogram (HBE) recording in a patient with an RCC-ventricular arrhythmia (VA).
Objective
This study aimed to assess whether high output RCC pace mapping (RCC-PM) would be helpful to avoid AVC injury in a patient with an RCC-VA in which there was no HBE at the optimal ablation site.
Methods
This study included 24 pacing sites from 22 patients with left outflow VAs in whom pace mapping on the RCC were performed. The distance from the RCC-PM site to the HBE site (Distance-RCC/HBE) was measured using a 3D-mapping system.
Results
We divided the 24 sites into 2 groups according to the paced QRS pattern. In the narrow/wide-group (QRS: 112.5±13.2 /135.2±9.3 msec, n=8), both a narrow and wide QRS were recorded during RCC-PM. In the wide-group (QRS: 143.7±12.8 msec, n=16), only a wide QRS was recorded. The distance-RCC/HBE was significantly shorter in the narrow/wide-group than wide-group (12.4±1.9 vs. 19.4±4.4 mm, P<0.001). There was no HBE at the RCC-PM site in all 24 sites. Using ROC curve, the best cutoff value for the distance-RCC/HBE as an optimal parameter to predict a narrow/wide QRS during RCC-PM was 12.5 mm with a sensitivity of 100% and specificity of 75.0% (AUC: 0.934; 95% CI: 0.832-1).
Conclusion
Although we must always take care to avoid AVC injury during any ablation including RCC-VA, we should be aware there may be a risk of AVC injury if the RCC-PM exhibits a narrow/wide QRS.