Reentrant atrial tachycardia after catheter ablation of coronary sinus accessory pathway

Figures

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  Fig. 1. (A) 12‑lead electrocardiogram (ECG) during sinus rhythm. (B) Simultaneous ECG and intracardiac electrogram (EGM) recordings during ventricular extrastimuli demonstrate that the earliest atrial activation site is consistently at the distal electrode in the coronary sinus, regardless of coupling interval [400 ms (left) or 320 ms (right)]. These findings indicate the absence of decremental properties in the ventriculoatrial pathway. (C) 12‑lead ECG during narrow QRS complex tachycardia (SVT1) with a heart rate of 175 bpm. (D) ECG and EGM during SVT1 reveal that the atrial activation sequence during the tachycardia cycle (345 ms) is identical to that observed during ventricular pacing. Numbers indicate intervals in milliseconds.

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  Fig. 2. (A) Activation maps during ventricular pacing using the 3-dimensional anatomical mapping system (CARTO 3; Biosense Webster). The upper panel shows the initial activation map of the left atrium in the anterior-posterior (AP) view, with its earliest atrial activation site (EAAS) located at the anterior mitral annulus (MA). The lower panel demonstrates the activation map after the EAAS shifted to the lateral MA. Pink and red tags indicate the radiofrequency ablation sites along the anterior and lateral MA applied at 30 W for up to 60 s using the ThermoCool SmartTouch SF ablation catheter. (B) Tracings during ventricular extrastimuli without (left) and with (right) ventriculoatrial (VA) block. Coronary sinus (CS) recordings are displayed at twice the usual scale. Red arrowheads indicate low voltage and fractionated potentials immediately after ventricular far-field potentials at the CS electrodes, which are observed only in the presence of VA conduction. (C) Intracardiac electrogram at the distal electrode of the ablation catheter during ventricular pacing exhibits the accessory pathway potential fused with far-field ventricular potential. (D) Catheter positions at the successful…

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  Fig. 3. (A) 12‑lead electrocardiogram (ECG) during SVT2. (B) Activation maps during SVT2 (tachycardia cycle length, 210 ms) with superimposed entrainment mapping. (C) Manifest entrainment during SVT2 induced by atrial rapid pacing from the left atrial (LA) bottom. Open and closed arrows indicate differences in surface P wave morphology in leads II and aVF during entrainment pacing versus tachycardia, suggesting fusion of the surface P wave during entrainment pacing. Notably, electrograms (EGMs) at the tricuspid annulus (TA) and coronary sinus (CS) are identical during pacing and tachycardia, indicating orthodromic captured (solid arrows). Conversely, EGMs at the LA bottom show antidromic capture (dashed arrows). (D) Activation map during SVT2 in left anterior oblique view. The local electrogram at the earliest atrial activation site within the coronary sinus demonstrates small fractionated potentials. (E) Catheter position at the successful ablation site. The distal tip of the ablation catheter is located near the area where accessory pathway conduction was previously eliminated. A few radiofrequency ablations were applied at 15 W for up to 60 s each, using the ThermoCool SmartTouch SF…

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  Fig. S1. Tracing of supraventricular tachycardia 1 (SVT1) after the change in the activation sequence at the coronary sinus (CS) electrodes.

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  Fig. S2. Tracing during pacing from the right ventricle (RV) prior to radiofrequency applications along the anterior mitral annulus. Small fractionated electrograms (red arrows), suggestive of accessory pathway potentials, were observed at the coronary sinus (CS) electrodes upon magnification of the electrogram amplitudes.