Case Challenges: A 71-Year-Old Man With Recurrent AFib After Prior Ablation
April 27, 2012
A 71-year-old male with a history of hypertension, mild-moderate LVH, non-obstructive CAD, and paroxysmal atrial fibrillation (AF) refractory to pharmacologic suppression with Dofetalide underwent radiofrequency (RF) catheter ablation 9 months ago. Ablation consisted of wide-antral circumferential pulmonary vein isolation (PVI). He did well post-procedure without recurrent AF.
In follow-up 6 months post-ablation, he had developed recurrent self-limited palpitations and an irregular heart beat. An event monitor confirmed recurrent paroxysms of AF. He was placed back on Dofetalide, but he continued to experience symptomatic arrhythmias lasting several minutes up to 6 hours. An auto-triggered event monitor documented recurrent AF with ventricular rates ranging from 80 to 100 beats per minute.
He was taken back to the EP laboratory for assessment of pulmonary vein isolation and repeat catheter ablation. A circular mapping catheter was placed in each of the four pulmonary veins. All pulmonary veins appeared isolated with evidence of entrance block (Figure 1):
|Figure 1: Recordings from the lasso catheter positioned in the ostium of each of the four pulmonary veins. Lasso position was confirmed with intracardiac echo guidance. The ablation catheter is positioned just outside the prior ablation line for each of the four veins. During sinus rhythm, lasso recordings demonstrate no pulmonary vein potentials consistent with entrance block.|