Successful ablation of an outlet septum ventricular tachycardia in a double-outlet right ventricle patient who underwent an extracardiac Fontan operation

Figures

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  Figure 1. A: The scheme of the heart structure. The aorta (Ao) and pulmonary artery (PA) were anastomosed (Damus–Kaye–Stansel operation). The Agilis NxT sheath (Abbott Medical) was advanced into the atrium by a transcaval cardiac puncture, which involved a direct needle puncture through a segment of the inferior vena cava (IVC) adjacent to the wall of the pulmonary venous atrium. B, C: Three-dimensional contrast cardiac computed tomography. D, G: Right ventriculography images show the location of the subpulmonary (sub-PA) and subaortic (sub-Ao) sides of the outlet septum. E, H: The cine-angiography images indicate the location of the earliest activation potential during a premature ventricular contraction (PVC) on the sub-PA side of the outlet septum. F, I: The cine-angiography images indicate the successful site with a confirmed prepotential on the sub-Ao side of the outlet septum. ABL = ablation catheter; LA = left atrium; LPA = left pulmonary artery; LV = left ventricle; RA = right atrium; RPA = right pulmonary artery; RV = right ventricle; RVG = right ventricle angiography; SVC = superior vena cava.

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  Figure 2. A: The resting 12-lead electrocardiogram (ECG) before the ablation. The 12-lead ECG shows a right upper axis in the frontal plane, qR in V1, and R/S ratio <1 in V5 and V6. The premature ventricular contractions (PVCs) have a left bundle branch block pattern and inferior axis. Each PVC morphology slightly differs in lead I and V1: R in I and rS in V1 (PVC1) and RS in I and small rS in V1 (PVC2). These PVCs could have originated from the outflow tract and it was assumed that their exit sites slightly differed. B: Twelve-lead ECGs exhibiting multiple PVCs during the session (PVC1, PVC2, and PVC3). C: Pace mapping obtained by pacing from the subpulmonary artery (sub-PA), subaortic (sub-Ao) region, and inferior part of the outlet septum. Good pace maps were obtained from the sub-PA side (PVC1) and sub-Ao side (PVC2) of the outlet septum.

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  Figure 3. The intracardiac electrograms at the ablation sites. A: The earliest ventricular activation during premature ventricular contraction (PVC) 2 was on the subaortic side of the outlet septum, which was 28 ms earlier than the QRS complex on the surface electrocardiogram (ECG). However, a discrete prepotential, which was 106 ms earlier than the QRS complex, was recorded. All PVCs were eliminated by delivering radiofrequency energy on the subaortic side of the outlet septum. B: PVC1 activation map on the subpulmonary side of the outlet septum revealed the earliest site of ventricular activation, which was 32 ms earlier than the QRS complex on the surface ECG. A prepotential was recorded on that side, which preceded the QRS complex by 61 ms. The pace map nearly matched the QRS morphology of PVC1.

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  Supplemental Figure 1. Three-dimensional computed tomography showing the atrium, right ventricle, outflow, and great arteries. Ao: aorta. CAVV: common atrioventricular valve. OS: outlet septum. PA: pulmonary artery. VIF: ventriculoinfundibular fold. VS: ventricular septum.

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  Supplemental Figure 2. The scheme of the assumed preferential conduction and exit sites in the outlet septum.