Wide QRS tachycardia associated with multiple accessory pathways in a patient with Wolff-Parkinson-White syndrome

Abstract

The electrocardiogram of a 14-year-old boy with recurrent palpitation showed a wide QRS regular tachycardia with a right bundle branch block and right-axis deviation of 226 beats per minute. Verapamil infusion terminated the tachycardia after a few minutes. Electrophysiological study revealed that this tachycardia was considered as a reentrant tachycardia associated with the anterograde left posterior accessory pathway (AP) and retrograde right septal AP. Radiofrequency application was performed and eliminated both APs, and there was no recurrence of wide QRS tachycardia. <Learning objective: Wide QRS tachycardia in young patients with no organic heart disease includes an uncommon supraventricular tachycardia. Wide QRS tachycardia utilizing different dual accessory pathways (APs) has rarely been reported. The refractory periods of the APs were shorter than that of atrioventricular node, and the shortest refractory period on anterograde and retrograde conduction was recorded at the left posterior AP and the right septal AP respectively. These findings were to be felt most consistent with the mechanism of maintaining an atrioventricular reentrant tachycardia with multiple APs.>.

Keywords: Antidromic atrioventricular reentrant tachycardia; Atrioventricular accessory pathway; Catheter ablation; Verapamil sensitive idiopathic ventricular tachycardia; Wolff–Parkinson–White syndrome.

Fig. 1

(A) 12-lead ECG showed a wide QRS regular tachycardia of a RBBB with RAD at 226 beats per minute. (B) 12-lead ECG during sinus rhythm after verapamil infusion showed the delta wave. Note the negative delta wave in V1 and abrupt transition to R > S in V2. In addition, the delta waves were negative in III and aVF but upright in II, which indicated the right septal AP. (C) Intracardiac electrograms (the left panel) and 12-lead ECG (the right panel) during HRA burst pacing of 200 ppm. The dotted line indicated that the earliest ventricular activation recorded by the ablation catheter which was placed at the right septum. (D) Intracardiac electrograms (the left panel) and 12-lead ECG (the right panel) during HRA burst pacing of 210 ppm. The dotted line indicated that the earliest ventricular activation recorded at the left posterior wall. The solid line indicated the ventricular activation which activated from CS distal to CS proximal site. Of note, the QRS morphology was identical to that of the tachycardia. ABL, ablation catheter; AP, accessory pathway; CS, coronary sinus; CSd, coronary sinus distal; ECG, electrocardiogram; HRA, high right atrium/atrial; RAD, right axis deviation; RBBB, right bundle branch block; RV, right ventricle/ventricular.

Fig. 1

(A) 12-lead ECG showed a wide QRS regular tachycardia of a RBBB with RAD at 226 beats per minute. (B) 12-lead ECG during sinus rhythm after verapamil infusion showed the delta wave. Note the negative delta wave in V1 and abrupt transition to R > S in V2. In addition, the delta waves were negative in III and aVF but upright in II, which indicated the right septal AP. (C) Intracardiac electrograms (the left panel) and 12-lead ECG (the right panel) during HRA burst pacing of 200 ppm. The dotted line indicated that the earliest ventricular activation recorded by the ablation catheter which was placed at the right septum. (D) Intracardiac electrograms (the left panel) and 12-lead ECG (the right panel) during HRA burst pacing of 210 ppm. The dotted line indicated that the earliest ventricular activation recorded at the left posterior wall. The solid line indicated the ventricular activation which activated from CS distal to CS proximal site. Of note, the QRS morphology was identical to that of the tachycardia. ABL, ablation catheter; AP, accessory pathway; CS, coronary sinus; CSd, coronary sinus distal; ECG, electrocardiogram; HRA, high right atrium/atrial; RAD, right axis deviation; RBBB, right bundle branch block; RV, right ventricle/ventricular.

Fig. 2

(A) Entrainment from the right septal AP. The ablation catheter was placed at the right septal AP. This pacing could capture the right atrial signal demonstrating the concealed entrainment and the PPI-TCL was measured as only 16 ms, which indicated that the reentrant circuit could include the right atrial septum. (B) A schema demonstrating tachycardia circuit. The pacing from the right atrial septum where the right accessory pathway could connect to the right atrium could demonstrate the concealed entrainment. Only the right atrial signal around the His recording site near the pacing site could be captured antidromically, however, the His potential could not be activated due to the ERP of AVN. The arrow and dotted one indicate orthodromic and antidromic capture, respectively. (C) Intracardiac electrograms (the left panel), 12-lead ECG (the mid panel), and the fluoroscopic image (the right panel) during successful ablation for the left posterior AP. Success site was shown in the right panel. Immediately after RF application, the earliest ventricular activation abruptly changed from the left posterior wall to the right septum (the left panel). The QRS morphology was also changed (the mid panel). (D) Intracardiac electrograms (the left panel), 12-lead ECG (the mid panel), and the fluoroscopic image (the right panel) during successful ablation for the right septal AP. Success site is shown in the right panel. The AP could be eliminated immediately after RF application (the left panel) and the delta wave disappeared (the mid panel). ABL, ablation catheter; AP, accessory pathway; CS, coronary sinus; LAO, left anterior oblique; PPI, post pacing interval; RA, right atrium; RAO, right anterior oblique; RF, radiofrequency; RV, right ventricle/ventricular; TCL, tachycardia cycle length.

Fig. 2

(A) Entrainment from the right septal AP. The ablation catheter was placed at the right septal AP. This pacing could capture the right atrial signal demonstrating the concealed entrainment and the PPI-TCL was measured as only 16 ms, which indicated that the reentrant circuit could include the right atrial septum. (B) A schema demonstrating tachycardia circuit. The pacing from the right atrial septum where the right accessory pathway could connect to the right atrium could demonstrate the concealed entrainment. Only the right atrial signal around the His recording site near the pacing site could be captured antidromically, however, the His potential could not be activated due to the ERP of AVN. The arrow and dotted one indicate orthodromic and antidromic capture, respectively. (C) Intracardiac electrograms (the left panel), 12-lead ECG (the mid panel), and the fluoroscopic image (the right panel) during successful ablation for the left posterior AP. Success site was shown in the right panel. Immediately after RF application, the earliest ventricular activation abruptly changed from the left posterior wall to the right septum (the left panel). The QRS morphology was also changed (the mid panel). (D) Intracardiac electrograms (the left panel), 12-lead ECG (the mid panel), and the fluoroscopic image (the right panel) during successful ablation for the right septal AP. Success site is shown in the right panel. The AP could be eliminated immediately after RF application (the left panel) and the delta wave disappeared (the mid panel). ABL, ablation catheter; AP, accessory pathway; CS, coronary sinus; LAO, left anterior oblique; PPI, post pacing interval; RA, right atrium; RAO, right anterior oblique; RF, radiofrequency; RV, right ventricle/ventricular; TCL, tachycardia cycle length.