Persistent atrial fibrillation originating from prominent Eustachian ridge: Precise identification of non–pulmonary vein foci using a high-density grid mapping catheter

Figures

• 

  Figure 1. Computed tomography (CT) images. A: Axial view. B: Sagittal view. C: Three-dimensional CT image of cavotricuspid isthmus level. The prominent Eustachian ridge (white and red arrows) is noted. LAO = left anterior oblique; RAO = right anterior oblique.

• 

  Figure 2. Intracardiac electrograms immediately after electrical cardioversion. A high-density grid catheter was situated at the prominent Eustachian ridge. A: A single atrial ectopic beat was recorded only at the high-density grid catheter. However, this excitement was not conducted to the surrounding right atrium and the coronary sinus, suggesting an intra-atrial conduction block. Then, 4 consecutive ectopic beats were conducted in the surrounding right atrium and the coronary sinus in a 2:1 fashion. B: A few seconds later, atrial ectopic beats originating from the Eustachian ridge triggered atrial fibrillation. The earliest atrial activation was recorded at the C-spline of the high-density grid catheter (not A- or D-spline), suggesting the precise identification of these non-PV foci. CS = coronary sinus; H = halo duodecapolar catheter; HD = high-density grid catheter; LAO = left anterior oblique; RA = high right atrium; RAO = right anterior oblique.

• 

  Figure 3. The earliest atrial activation site during atrial fibrillation (AF) initiation. A: A 3-D mapping system revealed that a high-density grid catheter was situated at the prominent Eustachian ridge. The green tag was marked at the earliest atrial activation site of the C-spline of the high-density grid catheter. B: After the high-density grid catheter was pulled out, the ablation catheter was positioned at the green tag sites. Intracardiac electrogram of the distal pair of the ablation catheter was the earliest activation site during AF initiation. A couple of radiofrequency applications were performed. ABL = ablation catheter; CS = coronary sinus; H = halo duodecapolar catheter; LAO = left anterior oblique; RA = high right atrium; RAO = right anterior oblique.