A specific pre-ablation sinus rhythm EGM pattern (≥4 deflections, ≥0.7 mV amplitude, ≥40 ms duration) predicted parasympathetic responses during AF ablation with 72% sensitivity and 91% specificity.
Observational (n=30)
Effect estimate: Sensitivity 72%, Specificity 91%
OBJECTIVES: This study sought to characterize left atrial (LA) sinus rhythm electrogram (EGM) patterns and their relationship to parasympathetic responses during atrial fibrillation (AF) ablation. BACKGROUND: The mechanistic basis of fractionated LA EGMs in patients with paroxysmal AF is not well understood. METHODS: We analyzed 1,662 LA ablation sites from 30 patients who underwent catheter ablation for paroxysmal AF. Pre-ablation EGM characteristics (number of deflections, amplitude, and duration) were measured in sinus rhythm. Parasympathetic responses during radiofrequency application (increase of atrial-His interval by > or =10 ms or decrease of sinus rate by > or =20%) were assessed at all sites. We also prospectively studied the effect of adenosine, a pharmacological agent mimicking acetylcholine signaling in myocytes, on LA EGMs. Finally, we performed mathematical simulations of atrial tissue to delineate possible mechanisms of fractionated EGMs in sinus rhythm. RESULTS: A specific pattern of pre-ablation sinus rhythm EGM (deflections > or =4, amplitude > or =0.7 mV, and duration > or =40 ms) was strongly associated with parasympathetic responses (sensitivity 72%, specificity 91%). The sites associated with these responses were found to be located mainly in the posterior wall of the LA. Adenosine administration and mathematical simulation of the effect of acetylcholine were able to reproduce a similar EGM pattern. CONCLUSIONS: Parasympathetic activation during AF ablation is associated with the presence of pre-ablation high-amplitude fractionated EGMs in sinus rhythm. Local acetylcholine release could potentially explain this phenomenon.
Lellouche et al. (Mon,) conducted a observational in Paroxysmal Atrial Fibrillation (n=30). Specific pattern of pre-ablation sinus rhythm EGM (deflections ≥4, amplitude ≥0.7 mV, and duration ≥40 ms) was evaluated on Parasympathetic responses during radiofrequency application (increase of atrial-His interval by ≥10 ms or decrease of sinus rate by ≥20%) (Sensitivity 72%, Specificity 91%). A specific pre-ablation sinus rhythm EGM pattern (≥4 deflections, ≥0.7 mV amplitude, ≥40 ms duration) predicted parasympathetic responses during AF ablation with 72% sensitivity and 91% specificity.