Perimitral atrial flutter with partial conduction block between left atrium and coronary sinus

Figures

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  Figure 1. Surface electrocardiogram and intracardiac electrocardiogram of atrial tachycardia. A: The 12-lead electrocardiogram demonstrated narrow QRS tachycardia with a cycle length of 210 ms. B: Intracardiac cardiogram during atrial tachycardia. CS = coronary sinus (1–2 = most distal pair, 9–10 = most proximal pair); RA = right atrium; II and V1 represent recordings from the 12-lead surface electrocardiogram.

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  Figure 2. Entrainment analysis during atrial tachycardia. A: Intracardiac recordings during the entrainment analysis at the anterior left atrium by the mapping catheter. The postpacing interval (PPI) at the anterior left atrium was equal to the tachycardia cycle length. B: The entrainment analysis at the middle of the coronary sinus (CS) by pacing from CS 5 to CS 6. The PPI at CS 5–6 was 290 ms. C: The entrainment analysis at the proximal part of the CS (CS 9–10). The PPI at CS 9–10 was longer than the tachycardia cycle length (270 ms). D: The entrainment analysis in the posterior left atrium demonstrated that the PPI at this site was consistent with the tachycardia cycle length. MAP = mapping catheter; other abbreviations are the same as in Figure 1.

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  Figure 3. The high-density 3-dimensional mapping of the left atrium and coronary sinus. The activation mapping demonstrated the septal-to-lateral activation sequence within the coronary sinus, which is opposite to that of the posterior left atrium.

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  Supplemental Figure 1. Termination of perimitral atrial tachycardia. Intracardiac recordings during radiofrequency application of the mitral annulus side on the mitral isthmus line demonstrated the termination of perimitral atrial tachycardia. CS, coronary sinus (1–2 = most distal pair, 9–10 = most proximal pair); ABL, ablation catheter; RA, right atrium; II and V1 represent recordings from the 12-lead surface electrocardiogram.