Diagnosing pseudo-conduction block across an anteromedial mitral ablation line: Limitations of bidirectional and differential pacing

摘要

Pseudo-block with differential pacing after initial anteromedial ablation lesion set. Pacing on opposite sides of the ablation line shows prolonged conduction times. Surface leads I, aVF, and V are shown, as well as intracardiac electrograms from the coronary sinus (CS), distal electrodes from the ablation catheter (ABL d), and a selective recording from an ultra-high-density multielectrode mapping catheter. Pacing was performed at a cycle length of 500 ms in this figure and those that follow. MV = mitral valve; RSPV = right superior pulmonary vein; * = site of pacing from the mapping catheter; ** = site of pacing from the distal ablation catheter. Differential pacing after initial ablation lesion set. Pacing after repositioning the mapping catheter to the left atrial appendage (LAA) results in shorter activation times compared with panel A (mapping catheter adjacent and superior to the ablation line), and is suggestive of line of block. Other abbreviations as previously described. * = site of pacing from the left atrial appendage; ** = site of pacing from the distal ablation catheter.