The impact of high-density atrioventricular dual-chamber mapping in a patient with a left epicardial accessory pathway

Figure 1. A–D: Dual chamber maps and activation pattern of the retrograde conduction via an accessory pathway from the endocardium. The deep red color shows the earliest activation site. The wavefront moved from the left ventricle to the left atrium (LA) and the Roving Probe shows the earliest atrial activation site (EAAS). The ablation energy (30W, 70 sec) was delivered at the EAAS from inside the LA, and the antegrade conduction and retrograde conduction terminated within a few seconds, however, the retrograde conduction recurred immediately after the discontinuation of the energy delivery (red tag). E: Fluoroscopic image of the ablation site. F: shows the local potential recorded from an Orion catheter at the EAAS in the LA, and the duration from the right ventricular pacing site to the local potential was 131ms (A-D, Roving Probe site). LIPV = left inferior pulmonary vein; LSVP = left superior pulmonary vein; RSPV = right superior pulmonary vein; CS = coronary sinus catheter; His = His bundle recording catheter; RV = right ventricle catheter; ABL = ablation catheter; RAO = right anterior oblique view; LAO = left anterior oblique view.

Figure 2. A–D: The activation pattern of the retrograde conduction via an accessory pathway from the coronary sinus. The red tag represents the ablation site from the left atrium (LA). The deep red color also represents the earliest activation site. The retrograde conduction spread from the left ventricle (LV) to the coronary sinus (CS) and then to the LA (A-D). The ablation energy (20W, 30 sec) was delivered from the CS (A-D, blue tag), and soon after the energy delivery inside the CS, the retrograde conduction was interrupted. E: The fluoroscopic image of the ablation site. F: The local potential recorded from the ablation catheter at the earliest activation site in the coronary sinus, and the duration from the right ventricular pacing site to the local potential was 128ms (B, blue tag site). LIPV = left inferior pulmonary vein; LSVP = left superior pulmonary vein; RSPV = right superior pulmonary vein; CS = coronary sinus catheter; His = His bundle recording catheter; RV = right ventricle catheter; ABL = ablation catheter; RAO = right anterior oblique view; LAO = left anterior oblique view.