Cryoablation for atrioventricular nodal re-entrant tachycardia associated with persistent left superior vena cava

Figures

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  Fig. 1. A) Three-dimensional computed tomography in right and left anterior oblique projections showing PLSVC with an enlarged CS ostium. B) Baseline intracardiac electrocardiogram during the sinus rhythm. C) Intracardiac electrogram during the clinical supraventricular tachycardia. The earliest atrial activation was observed at the His catheter with a septal ventriculoatrial time of −4 ms. His-synchronous premature ventricular contraction did not advance the subsequent atrial potentials. RAO, right anterior oblique; LAO, left anterior oblique; SVC, superior vena cava; IVC, inferior vena cava; RA, right atrium; GCV, great cardiac vein; HRA, high right atrium; His, His bundle; RV, right ventricle; H, His electrogram; PLSVC, persistent left superior vena cava; CS, coronary sinus.

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  Fig. 2. Intracardiac electrocardiograms and fluoroscopic views of cryoablation sites during sinus rhythm. A) The first cryomapping attempt site. The ABL was positioned at the posteroinferior aspect of the CS ostium with an A/V ratio of 0.05. The slow pathway potential (orange arrow) was observed; however, cryomapping at −30 °C for 20 s did not affect the tachycardia. B) The site of successful ablation. The fourth attempt of cryomapping terminated the tachycardia. ABL was positioned at the mid-anterior septum and with an A/V ratio of 0.36. C) The additional cryoablation site. ABL was positioned at the adjacent area to the site of tachycardia termination (B) with an A/V ratio of 0.33. HRA, high right atrium; His, His bundle; RV, right ventricle; RAO, right anterior oblique; LAO, left anterior oblique; H, His electrogram; ABL, ablation catheter; CS, coronary sinus.

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  Fig. 3. A) The fourth attempt of cryomapping at the mid-anterior septum terminated the tachycardia in 7 s. B) AV block occurred 22 s after cryoablation that was initiated during sinus rhythm. The AV conduction resumed immediately after ablation was discontinued. C) The AH interval after cryoablation remained the same as at baseline. AV, atrioventricular; HRA, high right atrium; His, His bundle; CS, coronary sinus; RV, right ventricle; ABL, ablation catheter; H, His electrogram.