Effective superior vena cava isolation using a novel C-shaped approach

Figures

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  Figure 1. Demonstration of the landmarks and the representative local electrograms. (A) Landmarks, from top to bottom: (a) end of the muscle sleeves, (b) ablation line, (c) earliest activation site during sinus rhythm, and (d) anatomical SVC—RA junction in the RAO 30° view; (B) Activation maps during sinus rhythm, RAO and left anterior oblique 60° views; the Lasso electrograms demonstrate clear SVC signals without far-field RA signals; (C) The same activation maps during sinus rhythm as in (B), but the Lasso catheter was placed lower, at the electrical SVC-RA junction where sharp SVC potentials were superimposed with blunt far-field RA electrograms. The arrows indicate the locations of the Lasso catheter. The square frames highlight the electrograms at the location of the Lasso catheter. SVC, superior vena cava; RA, right atrium; RAO, right anterior oblique.

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  Figure 2. A novel technique for isolating the superior vena cava (SVC) using a non-circumferential approach from the anterior-medial to posterior-lateral aspects was effective in isolating the SVC and reducing the risk of SVC stricture. Detailed ablation line schemes are demonstrated for all 12 cases. Except #4, all patients achieved SVC isolation without circumferential ablation. Among the 12 patients, the true lateral segment was ablated in 3 patients (#4, #5, and #10) and 5 patients had the posterolateral segment ablated (#2, #3, #7, #8, and #12).

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  Figure 3. Representative polygraphic tracings from two of the patients. CS 9–10, 7–8, 5–6, 3–4, and 1–2 illustrate the electrograms of the CS from proximal to distal. The Lasso catheter was placed in the SVC and the tracings represent the local SVC electrograms. (A) At the start of the tracing, the atria (demonstrated by CS signals) is in fibrillation. Upon SVC isolation, the atria return to sinus rhythm while the SVC is still in fibrillation. After SVC isolation, the fibrillation inside the SVC remains. (B) Another patient with the same catheter placement. After SVC isolation, a 100-J electrical cardioversion was applied to convert the rhythm. Paroxysmal non-sustained atrial tachycardia was observed inside the SVC, which was dissociated from the right atrium and did not induce atrial fibrillation. CS, coronary sinus; SVC, superior vena cava.