Mean AF voltage mapping yielded higher sensitivity (75% vs 63%) and specificity (79% vs 67%) for detecting MRI-DE-detected atrial fibrosis compared with voltage mapping during sinus rhythm.
Observational (n=20)
Does mean AF voltage mapping better correlate with MRI-DE detected atrial fibrosis than sinus rhythm voltage mapping in patients with persistent AF?
Mean AF voltage mapping provides superior correlation with MRI-detected atrial fibrosis compared to sinus rhythm voltage mapping in patients with persistent AF.
Absolute Event Rate: 75% vs 63%
BackgroundBipolar electrogram voltage during sinus rhythm (VSR) has been used as a surrogate for atrial fibrosis in guiding catheter ablation of persistent atrial fibrillation (AF), but the fixed rate and wavefront characteristics present during sinus rhythm may not accurately reflect underlying functional vulnerabilities responsible for AF maintenance.ObjectiveThe purpose of this study was determine whether, given adequate temporal sampling, the spatial distribution of mean AF voltage (VmAF) better correlates with delayed-enhancement magnetic resonance imaging (MRI-DE)–detected atrial fibrosis than VSR.MethodsAF was mapped (8 seconds) during index ablation for persistent AF (20 patients) using a 20-pole catheter (660 ± 28 points/map). After cardioversion, VSR was mapped (557 ± 326 points/map). Electroanatomic and MRI-DE maps were co-registered in 14 patients.ResultsThe time course of VmAF was assessed from 1–40 AF cycles (∼8 seconds) at 1113 locations. VmAF stabilized with sampling >4 seconds (mean voltage error 0.05 mV). Paired point analysis of VmAF from segments acquired 30 seconds apart (3667 sites; 15 patients) showed strong correlation (r = 0.95; P 4 seconds (mean voltage error 0.05 mV). Paired point analysis of VmAF from segments acquired 30 seconds apart (3667 sites; 15 patients) showed strong correlation (r = 0.95; P <.001). Delayed enhancement (DE) was assessed across the posterior left atrial (LA) wall, occupying 33% ± 13%. VmAF distributions were (median IQR) 0.21 0.14–0.35 mV in DE vs 0.52 0.34–0.77 mV in non-DE regions. VSR distributions were 1.34 0.65–2.48 mV in DE vs 2.37 1.27–3.97 mV in non-DE. VmAF threshold of 0.35 mV yielded sensitivity of 75% and specificity of 79% in detecting MRI-DE compared with 63% and 67%, respectively, for VSR (1.8-mV threshold). The correlation between low-voltage and posterior LA MRI-DE is significantly improved when acquired during AF vs sinus rhythm. With adequate sampling, mean AF voltage is a reproducible marker reflecting the functional response to the underlying persistent AF substrate.
Qureshi et al. (Mon,) conducted a observational in Persistent atrial fibrillation (n=20). Mean AF voltage (VmAF) mapping vs. Voltage during sinus rhythm (VSR) mapping was evaluated on Sensitivity in detecting MRI-DE-detected atrial fibrosis. Mean AF voltage mapping yielded higher sensitivity (75% vs 63%) and specificity (79% vs 67%) for detecting MRI-DE-detected atrial fibrosis compared with voltage mapping during sinus rhythm.