Importance of the length of the myocardial sleeve in the superior vena cava in patients with atrial fibrillation

FIGURE 1. The activation maps of the superior vena cava (SVC) and right atrium (RA), which were reconstructed with EnSite™ 3D‐mapping in the right side (left panels) and frontal (right panels) (A‐C) views. The white areas show the earliest activation sites during sinus rhythm and the white area indicates the sinus node (SN). The length of SVC (L‐SVC) was determined by the length from the top of the sinus node to the top of the myocardial sleeve in the SVC. The intra‐cardiac electrocardiograms show the SVC firing (D) and AF induced by the SVC firing (E) under intravenous administration of isoproterenol and adenosine triphosphate

FIGURE 2. The length of superior vena cava (L‐SVC) was determined by the length from the top of the sinus node to the top of the myocardial sleeve in the SVC. The plotting of the L‐SVC, which was determined by the length from the top of the sinus node to the top of the myocardial sleeve in the SVC in the SVCF and N‐SVCF groups (A). The frequency of SVC firing according to the 7 L‐SVC groups (B). AF, atrial fibrillation; ATP, adenosine triphosphate; ISP, isoproterenol

FIGURE 3. The length of superior vena cava (SVC) (L‐SVC) (A) was determined by the length from the top of the sinus node to the top of the myocardial sleeve in the SVC by EnSite™ images. The longer diameter of superior vena cava SVC (B) was determined by the diameter of SVC of the 1 cm above of junction of right atrium and SVC by computed tomography for radiofrequency of catheter ablation of atrial fibrillation. A receiver‐operating characteristic curve analysis of the L‐SVC (A) and longer diameter of SVC (B). The specificity and sensitivity of the SVC firing according to the L‐SVC and longer diameter of SVC were 0.835 and 0.727, for an L‐SVC of 37.00 mm, and 0.254 and 0.951, for longer diameter of SVC of 17.00 mm, respectively