Reconsidering the utility of manifest entrainment pacing in macroreentrant ventricular tachycardia: A case report

摘要

After insertion of a small electrode catheter into the posterior lateral vein and placement of the MAP catheter on the endocardial surface opposite to the vein (A), intracardiac electrograms were evaluated during both sinus rhythm and the ventricular tachycardia (VT) (B). After 2 sinus beats, the VT was spontaneously initiated. The sharp potential preceded the surface QRS complex by 66 ms during the VT, and the electrodes of the EPI 1-2 became the earliest activation sites of the entire electrodes. Entrainment pacing from the distal small electrodes (EPI 1-2) revealed entrainment with concealed fusion (C). I, II, III, aVR, aVL, aVF, V1, V2, V3, V4, and V5 represent the surface electrocardiogram leads; CS 1-2 to 19-20 represent the distal to proximal coronary sinus recordings; MAP 1-2 represents the electrograms of the ablation catheter; and EPI 1-2 to 7-8 represent the distal-to-proximal recordings of the small electrode catheter. CS = coronary sinus; E-QRS = electrograms-QRS; PCL = pacing cycle length; PPI = postpacing interval; S-QRS = stimulus-QRS; TCL = tachycardia cycle length.