Figure 1: A: The preoperative electrocardiogram indicates sinus rhythm.
B: Intracardiac echocardiography (ICE) shows an echolucent shadow
alongside the left atrium (LA), consistent with a Persistent Left
Superior Vena Cava (PLSVC).
C: Three-dimensional electroanatomical map of the left atrium in sinus
rhythm, viewed from the left side.
D: Three-dimensional electroanatomical map of the left atrium in sinus
rhythm, viewed from the posterior-anterior perspective.
E: Three-dimensional electroanatomical map of the left atrium in sinus
rhythm, viewed from the right side.
F: Three-dimensional electroanatomical map of the left atrium in sinus
rhythm, viewed from the anterior-posterior perspective.
G: Ablation steps include gap ablation within the pulmonary veins,
expansion of the ablation area, and linear ablation at the roof.
Post-operatively, AF was induced using an S1S1 pacing protocol (Figure
2A), suggesting ectopic electrical activity originating from
non-pulmonary vein sources. Subsequently, a three-dimensional
electroanatomical mapping of the right atrium was performed, identifying
the presence of a PLSVC (Figures 2B, 2D). The electrical potentials in
the superior vena cava (SVC) were regular and slower compared to those
in the coronary sinus (CS), indicating passive activation (Figure 2C).
In contrast, the PLSVC exhibited prolonged, fragmented, and regular
potentials, suggesting it as a driver of the AF (Figure 2E).Ablation was
performed at the site of fragmented potentials within the PLSVC, with an
ablation index (AI) of 280-300, and the ablation duration was 10
seconds. Complete electrical isolation of the PLSVC successfully
terminated the AF (Figures 2F, 2G). Following the procedure, intravenous
isoproterenol was administered, and repeated electrophysiological tests
with atrial pacing were conducted, none of which could induce any
arrhythmias.