PMC5420053_01
Electrocardiogram, intracardiac electrogram with entrainment, and 3-dimensional (3D) electroanatomic map of patient 1. A: The surface electrocardiogram. B: The electrogram of patient 1 shows atrial tachycardia. Entrainment was performed from the posterior wall of the LA with a postpacing interval of 453 ms. C: The electrogram recorded when the ablator tip in the atrial tachycardia origin site reveals fractionated irregular rhythm as atrial fibrillation with 2:1 and 3:1 conduction. D: The 3D atrial activation map reveals atrial activation starting rhythmically at a small area (0.25 cm2) from where it spread centrifugally (black arrows). The electrogram on the right side reveals a transition from atrial fibrillation in the central area to an organized atrial tachycardia. E: The 3D left atrial voltage map reveals a large low-voltage zone in the posterior wall. The electrogram on the right side reveals a local signal in sinus rhythm after ablation. ABL = tip of ablator; CS = coronary sinus; CSD = distal coronary sinus; CSM = middle coronary sinus; CSP = proximal coronary sinus; LA = left atrium; LIPV = left inferior pulmonary vein; LSPV = left superior pulmonary vein; RIPV = right inferior pulmonary vein; RSPV = right superior pulmonary vein.
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The electrical wavefront spread centrifugally from these foci, and the electrogram showed a change from irregular AF to a more organized rhythm without beat-to-beat variation (Figures 1D and 2D).
PMC5420053_02
Electrocardiogram, intracardiac electrogram with entrainment, and 3-dimensional (3D) electroanatomic map of patient 1. A: The surface electrocardiogram. B: The electrogram of patient 1 shows atrial tachycardia. Entrainment was performed from the posterior wall of the LA with a postpacing interval of 453 ms. C: The electrogram recorded when the ablator tip in the atrial tachycardia origin site reveals fractionated irregular rhythm as atrial fibrillation with 2:1 and 3:1 conduction. D: The 3D atrial activation map reveals atrial activation starting rhythmically at a small area (0.25 cm2) from where it spread centrifugally (black arrows). The electrogram on the right side reveals a transition from atrial fibrillation in the central area to an organized atrial tachycardia. E: The 3D left atrial voltage map reveals a large low-voltage zone in the posterior wall. The electrogram on the right side reveals a local signal in sinus rhythm after ablation. ABL = tip of ablator; CS = coronary sinus; CSD = distal coronary sinus; CSM = middle coronary sinus; CSP = proximal coronary sinus; LA = left atrium; LIPV = left inferior pulmonary vein; LSPV = left superior pulmonary vein; RIPV = right inferior pulmonary vein; RSPV = right superior pulmonary vein.
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The electrical wavefront spread centrifugally from these foci, and the electrogram showed a change from irregular AF to a more organized rhythm without beat-to-beat variation (Figures 1D and 2D).
Electrocardiogram, intracardiac electrogram with entrainment, and 3-dimensional (3D) electroanatomic map of patient 2. A: The surface electrocardiogram. B: The electrogram of patient 2 shows atrial tachycardia. Entrainment was performed from the high crista terminalis with a postpacing interval of 438 ms. C: The electrogram recorded when the ablator tip in the atrial tachycardia origin site reveals fractionated irregular rhythm as atrial fibrillation with 2:1 and 3:1 conduction. D: The 3D atrial activation map reveals atrial activation starting rhythmically at a small area (0.25 cm2) from where it spreads centrifugally (black arrows). The electrogram on the right side reveals a transition from atrial fibrillation in the central area to an organized atrial tachycardia. E: The 3D right atrial voltage map reveals a moderate low-voltage zone in the septum. The electrogram on the right side reveals a local signal in sinus rhythm after ablation. ABL = tip of ablator; CS = coronary sinus; CSD = distal coronary sinus; CSM = middle coronary sinus; CSP = proximal coronary sinus; CT = crista terminalis; RA = right atrium
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AT (Figure 2). After a failed treatment with diltiazem and bisoprolol, the patient was referred for electrophysiological study and ablation. Manifest entrainment was demonstrated, and the duration of postpacing interval minus tachycardia cycle length was 71 ms at the high crista terminalis (Figure 2B). The earliest activation site was localized in a small area (0.25 cm2) in the right atrial septum (Figures 2D and 2E) with local AF and 2:1 and 3:1 local conduction. Intermittent conduction to the low-voltage area from the fractionated electrogram at the right intra-atrial septum resulted in an organized AT (Figure 2C). The electrical wavefront spread centrifugally from these foci, and the electrogram showed a change from irregular AF to a more organized rhythm without beat-to-beat variation (Figures 1D and 2D).