PC-578-02 JUNCTIONAL TACHYCARDIA

Abstract

Junctional ectopic tachycardia (JET) is a rare tachyarrhythmia in adults. The precise site of origin within the AV junction is unknown. N/A N/A A 71-year-old male presented with dyspnea on exertion and recently diagnosed tachycardia in March 2021. He had a history of diabetes mellitus, obesity, hypertension, obstructive sleep apnea, and COVID-19 in 2020. A 14-day monitor demonstrated 43% supraventricular ectopy SVE burden and short runs of SVT. He presented for an electrophysiology (EP) study. He presented to the EP lab in sinus rhythm with frequent SVE. Multipolar catheters were placed in the His bundle region, right atrium, coronary sinus, and right ventricle. The SVE beats had the same QRS morphology, and an identical HV interval and His-right bundle activation sequence as in sinus rhythm and no retrograde conduction, consistent with premature junctional complexes (PJCs). Occasional short bursts of junctional tachycardia were noted. Isoproterenol was titrated to a maximum dose of 8 mcg/min. No other SVT was inducible with atrial overdrive pacing or programmed stimulation or with isoproterenol infusion. A 6 mm tip cryoablation catheter was advanced to the right atrium to the anatomical location of the slow pathway in the inferior triangle of Koch using an electroanatomic mapping system (EnSite NavX). Signals immediately prior to ablation (Figure 1) were notable for a pre-potential 26 ms prior to the His with PJCs. Cryoablation was performed at this site (Figure 2) with resolution of the PJCs at the onset of the freeze. After thawing, a second freeze was administered. No further PJCs were noted at baseline or with isoproterenol infusion. JET could originate from anywhere within the AV node or proximal His bundle. The application of cryoablation at a typical AV nodal slow pathway location with a preceding pre- potential and immediate obliteration of PJCs suggests that the origin in this case was from this region rather than a true His bundle extrasystole. Identification of pre-potentials to the junctional ectopy can guide safe ablation of this dysrhythmia.View Large Image Figure ViewerDownload Hi-res image Download (PPT)