Ablation From the Right Coronary Cusp Eliminated Premature Ventricular Contractions Originating From the Proximal Left Anterior Fascicle

A 42-year-old female patient was referred for ablation for high-burden (21.0%) premature ventricular contractions (PVC), with a narrow QRS duration and a prominent inferior frontal plane QRS axis (Figure A).

Figure.

(A) Electrogram characteristics of the premature ventricular contraction (PVC) and its target. (B) Mapping and ablation of the PVC. (C) The activation time of the left His bundle and the right coronary cusp (RCC) was later than that of the target. The left His bundle potential preceded the QRS by 52 ms during sinus rhythm. A small Purkinje potential (red arrows) preceding the ventricular potential was recorded in the RCC. AAo, ascending aorta; LV, left ventricle; NCC, non-coronary cusp.

During the procedure, the PVC target (Figure A), with a significant His-Purkinje potential preceding QRS onset during PVC and sinus rhythm, was located at the proximal left anterior fascicle (LAF; Figure). Due to a deep inspiration and a transient left bundle branch block, ablation attempt in the left ventricle failed (Figure B, Supplementary Figure 1A). The short distance between the target and the right coronary cusp (RCC) was noted (3.2 mm; Figure B). After assessment (Supplementary Figure 2), titrated ablation was performed from the RCC that eliminated the PVC successfully in 5.02 s (Figure B, Supplementary Figure 1B). During the observation period, the QRS morphology recovered (Supplementary Figure 1C). During an 18-month follow-up, the patient was free of PVC without anti-arrhythmics.

In this case, the PVC originated from the proximal LAF near the left His bundle region. Ablation attempt around the region failed due to the high risk of conduction block. Fortunately, thanks to the short distance between the originating site and the RCC, ablation from the RCC was a viable alternative. For those idiopathic PVC originating from the proximal LAF, ablation in the RCC, requiring caution,¹ may improve clinical practice with better stability and easier manipulation.

Disclosures

The authors declare no conflict of interest.

Supplementary Files

Please find supplementary file(s);

http://dx.doi.org/10.1253/circj.CJ-19-0315

Reference

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