PMC9808440_01
(A) Activation map of the left atrium during high right atrial pacing before ablation. Left panel: The local activation time map showed breakthrough at the right-sided pulmonary vein carina and the anterior wall of left atrium. Right panel: The coherent map showed the breakthrough sites more clearly. In total, 5256 points were mapped. (B) Activation map of the left atrium after the first-pass ablation. Left panel: The coherent map after the first-pass ablation also showed that the breakthrough site was the same as before ablation. Right panel: The coherent map with isochronal mapping clearly showed the breakthrough sites.
gr1.jpg
PMC9808440_01_gr1.jpg
f0005
Prior to ablation, the activation map of the LA during high right atrial pacing showed two sites of breakthrough, one at the right-sided PV carina and the other at the anterior LA, which appeared to be via Bachmann's bundle (Fig. 1A). The ripple map is shown in Video 1, and the coherent map is shown in Fig. 1B.
Activation map of the left and right atrium during pacing from the right-sided pulmonary vein carina. The earliest activation site was the posterior right atrium. The interval from pacing to the local potential was 32 ms. The anterior wall along the right side of the pulmonary vein was also activated early; however, the interval from pacing to the local potential was 43 ms. Red and pink tags indicate the sites of radiofrequency application during first-pass pulmonary vein isolation.. EAAS, earliest atrial activation site; RA, right atrium; LA, left atrium.
gr2.jpg
PMC9808440_01_gr2.jpg
f0010
An activation map of the LA and RA revealed that the site of earliest activation was the posterior RA, which implied a direct connection between the right-sided PVs and RA (Fig. 2, Video 2).
(A) Intracardiac electrograms and fluoroscopic imaging at the first successful ablation site in the right atrium. The right-sided pulmonary vein potentials disappeared; however, reconnection of these potentials was confirmed 5 min after isolation was achieved. (B) Intracardiac electrograms and fluoroscopic imaging at the second successful ablation site in the left atrium. The right-sided pulmonary vein potentials disappeared immediately after applications were initiated and never reconnected. (C) Three-dimensional imaging showing the sites of successful ablation in both atria. The blue tag indicates the first successful radiofrequency application site in the posterior right atrium. The orange tag indicates the second successful radiofrequency application site in the left atrium. The distance between these two sites was 18.2 mm. The red and pink tags indicate the first-pass radiofrequency application sites.. ABL, ablation catheter; RA, right atrium; CS, coronary sinus; prox., proximal; dist., distal; RSPV, right superior pulmonary vein; RPV, right pulmonary vein; AP, anteroposterior view; LAO, left anterior oblique view.
gr3c.jpg
PMC9808440_01_gr3c.jpg
f0015
This resulted in isolation of the right-sided PVs with bi-directional block (Fig. 3A); however, the time to attain isolation after RF applications were initiated was somewhat long (10 s). Then, we performed RF applications using the same power settings on the opposite site (right PV carina), which achieved PVI immediately after applications began (Fig. 3B).