Preferential Pathway Pacing within the Aortic Sinus of Valsalva: Strong Evidence for the Existence of Preferential Conduction with Different Exit Sites Traversing the Ventricular Septum

Abstract

A 57-year-old male who presented with frequent ventricular premature contraction (VPC) was referred for catheter ablation. Two different QRS morphologies (VPC1 and VPC2) were recorded. Pace mapping at the right ventricular outflow (RVOT) was identical to VPC1 without latency. During the mapping within the right sinus of Valsalva where the RF applications were successful for elimination of VPC, discrete prepotential was recorded and the pace mapping produced both VPC1 and VPC2 morphology with different latency. These electrophysiological findings were thought to prove the existence of preferential pathway traversing the ventricular outflow septum with different exit sites.

Disappearance of Idiopathic Outflow Tract Premature Ventricular Contractions After Catheter Ablation of Overt Accessory Pathways

“…Therefore, the occurrence of these PPs and their association with His‐bundle activation time suggests that islets of residual cells (located within the fibrous trigone) that once originated from the conduction system and failed to regress during maturation might be actively involved in the genesis of VAs originating from this region. Similar findings have been described in several reports …”

“…Similar findings have been described in several reports. [5][6][7][22][23][24][26][27][28][29][30][31][32][33][34][35] The observations of our present study highlight the potential existence of another unique and complex mechanism for arrhythmia genesis. In this case series, we present 6 patients with simultaneous occurrence of pre-excitation and OT, and in 1 case inflow tract, PVCs with fixed coupling intervals.…”

Preferential conduction during focal atrial tachycardia arising from the noncoronary cusp

“…Several reports have suggested the existence of preferential conduction during premature ventricular contractions arising from the aortic mitral continuity and aortic sinuses 1, 2, 8, 9. Our case demonstrates that preferential conduction may also occur during AT arising from the aortic sinus.…”

Catheter ablation of premature ventricular complexes with low intraprocedural burden guided exclusively by pace‐mapping

“…Second, although they usually correlate, sites with the earliest activation time can be spatially distant from sites with the best pace-map due to the presence of abnormal insulated strands of myocardium on the epicardial aspect of the fibrous walls of the valvar sinuses. 22,23 Yamada et al 24 have reported a spatial mismatch between the best activation mapping site and best pace-mapping site due to this "preferential conduction" via fibers connecting the focus to the exit sites in 10% of their study patients. A similar concept has also been suggested with papillary muscle VAs.…”