Fibrillatory wave amplitude on transesophageal ECG as a marker of left atrial low-voltage areas in patients with persistent atrial fibrillation.

BACKGROUND

Low-voltage areas (LVAs) are frequently observed in patients with persistent atrial fibrillation (PeAF) and may represent adverse atrial remodeling. However, noninvasive method of evaluating LAVs is not well established.

METHODS

In a cohort of 68 patients with PeAF, endocardial voltage maps of left atrium (LA) were created during sinus rhythm after pulmonary vein isolation (PVI). LVAs were defined as areas with electrogram amplitudes <0.5 mV. LA-LVAs were correlated with clinical, echocardiographic, surface, and transesophageal electrocardiography (TE-ECG) variables.

RESULTS

LA voltage mapping revealed any degree of LA-LVAs in 50 (73.5%) patients. Patients with LA-LVAs were older, had a longer history of AF, and lower fibrillatory wave (F wave) amplitude on TE-ECG (0.27 ± 0.06 vs 0.39 ± 0.08 mv, p < .01) as compared to patients without LA-LVAs. The extent of LA-LVAs was weakly correlated with age (R = 0.36, p = .03) and AF duration (R = 0.26, p = .02), but significantly correlated with F-wave amplitude on TE-ECG (R = -0.57, p < .01). Only F-wave amplitude on TE-ECG was found as independent predictor for the presence of LA-LVAs (OR = 1.53, 95% CI = 1.09-2.96, p = .03). A receiver operating characteristic (ROC) curve identified an F-wave amplitude of 0.29 mV (AUC = 0.788; sensitivity = 68.4%; specificity = 73.2%) on TE-ECG as the optimal cutoff value for predicting LA-LVAs.

CONCLUSIONS

As a noninvasive investigation, F-wave amplitude on TE-ECG may be used as an indicator for the presence of LA-LVAs.