Successful Non‐Coronary Cusp Ablation in Type B Wolff–Parkinson–White Syndrome With an rS Pattern in Lead V1

Figures

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  FIGURE 1. Surface electrocardiogram and baseline electrophysiological findings in type B Wolff–Parkinson‐White syndrome. (A) The delta waves were positive in Leads I, II, III, aVF, and V1. According to the Arruda algorithm, these findings suggested a right anterior or anterolateral accessory pathway. The initial r‐wave amplitudes in Leads V1 and V2 were 0.5 and 0.9 mV, respectively. (B) The earliest ventricular activation during sinus rhythm and the earliest atrial activation during orthodromic atrioventricular reentrant tachycardia (AVRT) were both localized to the distal His bundle region, suggesting a para‐Hisian accessory pathway. ABL, ablation catheter; CS, coronary sinus; HIS, His bundle; RA, right atrium; RV, right ventricle.

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  FIGURE 2. Electroanatomical mapping of retrograde and antegrade conduction through a para‐Hisian accessory pathway. (A) During AVRT, the earliest atrial activation was localized to the anteroseptal region at the His bundle recording site. (B) During sinus rhythm, the earliest ventricular activation was identified on the right ventricular anterior wall adjacent to the His bundle recording site. CS, coronary sinus; RA, right atrium; RV, right ventricle; IVC, inferior vena cava.

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  FIGURE 3. Intracardiac electrograms, catheter positions, and EnSite electroanatomical maps of the right atrium and aorta at the successful ablation site during orthodromic atrioventricular reentrant tachycardia. (A) The ablation catheter (yellow arrow) was positioned within the noncoronary cusp (NCC), where the local atrial electrogram showed activation timing comparable to that recorded by the His bundle catheter. (B) The green tag indicates the successful ablation site within the NCC, the yellow tags indicate sites where His bundle potentials were recorded, and the blue tag indicates the earliest atrial activation site in the right atrium. The earliest right atrial activation site and the successful NCC ablation site were located opposite each other, approximately 8 mm apart. ABL, ablation catheter; Ao, aorta; RA, right atrium; HIS, His bundle; HRA, high right atrium; IVC, inferior vena cava; LAO, left anterior oblique; RAO, right anterior oblique; RV, right ventricle.

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  FIGURE 4. Termination of atrioventricular reentrant tachycardia during noncoronary cusp ablation. Radiofrequency (RF) energy was delivered at 30 W within the NCC. AVRT terminated with ventriculoatrial block 5.5 s after the initiation of RF delivery, followed by restoration of sinus rhythm with complete disappearance of the delta wave. No subsequent retrograde accessory pathway conduction was observed, confirming complete elimination of accessory pathway conduction.