Electrophysiological study
Two quadripolar mapping catheters including a His bundle catheter and a
right ventricular apex (RVA) catheter were placed via the right femoral
vein under fluoroscopy guidance. A decapolar (inter-electode spaces
being 2-8-2 mm) coronary sinus (CS) vein catheter was placed via the
left/right femoral vein. Intracardiac electrocardiograms during sinus
rhythm and arrhythmias were analyzed. EPS techniques including burst
pacing, programmed stimulation (S1, S1S2, S1S2S3), right ventricular
apex (RVA) entrainment, and His bundle refractory period premature
ventricular stimuli were used for differential diagnosis.