The use of noninvasive electrocardiographic mapping in an exercise-induced and nonsustained atrial tachycardia ablation

Figure 1. A: Basal electrocardiogram (ECG) showing an ectopic atrial rhythm, early repolarization pattern. B: Strip of a 24-hour ambulatory ECG recorded during basketball training showing an episode of large-QRS tachycardia (various degrees of aberrant ventricular conduction like right bundle branch block) with a maximum rate of 250 beats/min. C–E: Samples of LINQ (Medtronic, Minneapolis, MN) arrhythmic events recorded during basketball training, bike ride, and gym session.

Figure 2. Summary of noninvasive electrocardiographic mapping. A: A 252-electrode vest is applied to the patient’s torso. It is followed by a noncontrast thoracic computed tomography scan to obtain high-resolution images of the heart and the vest electrodes. The electrodes’ position and 3D epicardial biatrial geometry are obtained via segmentation from the computed tomography images. B: Vest is connected to the electrocardiographic mapping system and surface potentials are recorded. The patient starts exercise testing. C: During the exam focal atrial tachycardia (FAT) is triggered. D: The system reconstructs epicardial potentials and unipolar electrograms from torso potentials with “single beat analysis” using mathematical reconstruction algorithms. The platform creates a potential map, suggestive for FAT originating from the superior vena cava (SVC) or right atrium - SVC (Supplementary material online, video 1).

Figure 3. Ablation procedure with CARTO 3 system (Biosense Webster, Inc, Diamond Bar, CA). A: After right atrium (RA) anatomical reconstruction, a PentaRay multipolar catheter (Biosense Webster, Inc) is advanced into the superior vena cava (SVC), showing rapid potentials (blue circle). B: After phrenic nerve course identification through high-energy pacing (blue tags) and replacing the PentaRay with a LASSO catheter (Biosense Webster, Inc), we perform SVC isolation (red/rose tags). C: Evidence of SVC isolation occurring during radiofrequency ablation; note the loss of signals on LASSO catheter (blue arrow). We confirm the isolation through circular mapping catheter and check entrance/exit block also during intravenous adenosine administration. CS = coronary sinus; IVC = inferior vena cava; TA = tricuspid annulus. (See supplementary material online, video 2).