Figure 2.

A: Volume-rendered image reconstructed using cardiac computed tomography showing the location of the coronary sinus. B–D: Images of the epicardial adipose tissue surrounding both atrioventricular (AV) junctions and the inferior pyramidal space (black-dotted line) were reconstructed. When viewed from the anterosuperior direction, the transparency of the cardiac volume was increased (C) and the volume data of the AV epicardial adipose tissue along with the coronary venous system could be obtained (D), which were integrated with the electroanatomic mapping (see Figure 3). The coronary sinus (CS) was located on the left atrial side of the left AV junction (A). The CS aneurysm originated from the bifurcation of the inferior interventricular vein (IIV) and small cardiac vein (SCV), and was located just beneath the basal inferior left ventricle in contact with mitral valve annulus (MVA) at its neck (D). Red arrow in D indicates the estimated site of the accessory pathway. E, F: Fluoroscopy-like volume-rendered images were reconstructed to guide the procedure using cardiac computed tomography, as shown from the 30° right anterior oblique (E) and 45° left anterior oblique (F) views. Note the consistency of the fluoroscopic images during the procedure (see Figure 3). White arrows indicate the CS aneurysm. Ao = ascending aorta; ICV = inferior caval vein; ILV = inferolateral vein; LA = left atrium; LV = left ventricle; PT = pulmonary trunk; RA = right atrium; RV = right ventricle; SIV = superior interventricular vein; TVA = tricuspid valve annulus.