Prevalence and Characteristics of Atrial Tachycardia From Noncoronary Aortic Cusp During Atrial Fibrillation Catheter Ablation

Figures

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  Figure 1. Twelve-lead electrocardiography and intracardiac electrocardiograms. (A) AT was spontaneously terminated. It was difficult to discriminate the morphology of P-waves in real time because of overlap with the T wave. (B) AT was induced by rapid atrial pacing with a pacing interval of 280 ms. The earliest activation was recorded at the proximal electrodes of the His-bundle catheter. At this site, the local activation preceded the onset of surface P-wave by 33 ms. AT = atrial tachycardia; aVF = augmented vector foot; aVL = augmented vector left; aVR = augmented vector right; CS = coronary sinus; RA = right atrium; RV = right ventricular.

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  Figure 2. P-wave characteristics during AT. There was no consistent rule on P-wave positivity during AT from the noncoronary cusp. In the majority of cases, leads I, aVL, and V6 did not show negative P-wave. AT = atrial tachycardia; aVF = augmented vector foot; aVL = augmented vector left; aVR = augmented vector right.

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  Figure 3. Successful ablation site. (A) The activation map of atrial tachycardia from the noncoronary cusp showed focal electrical propagation from the anterior interatrial septum. The white arrow indicates the successful ablation site at NCC. (B) Using intracardiac echocardiography, 3 different aortic cusps (NCC, RCC, and LCC) can be visualized on the 3-dimensional electroanatomical mapping image. The white arrow indicates the successful ablation site at NCC. (C) During radiofrequency energy application, the catheter stability inside NCC can be monitored by intracardiac echocardiography. (D, E) The LAO and RAO fluoroscopic images showed that the ablation catheter was placed inside the aortic root with the catheter tip toward the NCC. Ao = aorta; LA = left atrium; LAO = left anterior oblique; LAT = local activation time; LCC = left coronary cusp; NCC = non-coronary cusp; RA = right atrium; RAO = right anterior oblique; RCC = right coronary cusp; RV = right ventricular; RVOT = right ventricular outflow tract.

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  Figure 4. Intracardiac electrograms at a successful Abl site. (A) shows the electrograms recordings of multiple diagnostic and Abl catheters at successful Abl site, which did not recur during long-term follow-up. (B) shows the successful Abl site local atrial electrograms inside NCC on diatal Abl catheter of 5 different NCC AT cases. The asterisk marks indicate atrial electrograms, which are larger than the ventricular electrogram amplitudes. The local atrial electrograms presented sharp biphasic electrograms (a-d) or a long fragmented potential (e). Abl = ablation; CS = coronary sinus; NCC = non-coronary cusp; RA = right atrium. *Atrial electrogram at NCC.