A case of successful catheter ablation for biatrial reentrant tachycardia after a Mustard operation for dextro-transposition of the great arteries

Figures

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  Figure 1. Activation map of each atrium and entrainment pacing studies. A: The activation map of systemic venous atrium (SVA) from the left anterior view shows a focal pattern with the earliest site of the lower posterior septum. B, C: The activation map of pulmonary venous atrium (PVA) from posterior view (B) and left anterior oblique view (C) show a focal pattern with the earliest site of right superior pulmonary vein (RSPV) ostium. Each earliest site faced the contralateral atrium chamber. The entrainment pacing sites are shown with white tags. “postpacing interval − tachycardia cycle length (TCL) < 30 ms” sites are located in discrete points in both atria. The entrainment pacing site at inferior vena cava (IVC) closest to the cavotricuspid isthmus in image A was out of the circuit. Pink tags in images A and C show effective ablation sites that resulted in TCL prolongation. The orange tag in image B shows a successful ablation site. LAA = left atrial appendage; MA = mitral annulus; SVC = superior vena cava; TA = tricuspid annulus.

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  Figure 2. Biatrial activation map from posterior cranial view and local potentials at each location: a: the earliest activation site of pulmonary venous atrium (PVA); b: posterolateral wall of PVA; c: the earliest activation site of systemic venous atrium (SVA); d: posterior septum of PVA facing the earliest site of SVA; e: superior vena cava (SVC) adjacent to the earliest site of PVA; and f: the earliest site of SVA adjacent to site d after tachycardia cycle length (TCL) prolongation by 30 ms by ablation of site a. Postpacing interval − TCL < 30 ms was confirmed at sites b, c, d, and e. Continuous fractionated potentials between double potential were observed at the earliest sites of each atrial chamber, a and f. Other abbreviations as in Figure 1.

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  Figure 3. Estimation of septal patch location based on a voltage map and effective ablation sites. The septal patch edge is drawn with white dotted lines. A: A voltage map of pulmonary venous atrium (PVA) from left anterior oblique view shows that the entrance of excitation propagation from systemic venous atrium (SVA) to PVA is located on the upper edge of the patch (white waved arrow). B: A voltage map of SVA from right lateral view. The patch was sutured just below the superior vena cava (SVC) with its posterior edge adjacent to the right superior pulmonary vein (RSPV). C: A voltage map of SVA from right anterior oblique view shows that a propagation entrance from PVA to SVA is located on the lower edge of the patch that faced PVA (white waved arrow). D: Biatrial activation map from right anterior oblique view shows the successful ablation site in PVA with an orange tag. After effective ablation to the earliest site of SVA (red cross mark) resulted in tachycardia cycle length prolongation by 60 ms, the entrance was estimated to have changed from the lower edge to the anterior edge of the patch, which is an alternative pathway (red dotted arrow), because the success site of PVA was…