5.1 Association between localized LVA presence and whole left atrial electrophysiological degeneration.
Patients with localized LVAs demonstrated whole left atrial degeneration, represented by an extensive mean regional voltage reduction and a low left atrial total conduction velocity. Several upstream factors causing atrial fibrosis have been reported, including atrial stretch, aging, AF burden, hypertension, heart failure, alcohol, obesity, and obstructive sleep apnea.13-17 These upstream factors would promote atrial fibrosis not only at localized areas, but also across the entire atrial myocardium. Therefore, when the voltages at some portions of the left atrium were below 0.50mV - which is a commonly used cut-off value of LVA - voltages at other areas likely decreased in parallel, even if not below 0.50 mV.
Myocardial degeneration of the entire atrium in AF patients has also been reported. Teh et al showed that AF patients had lower mean voltage, slower conduction, and more prevalent complex signals at a majority of left atrial regions than controls.13