Endothelial Dysfunction in Patients With Lone AF and AF Patients With Comorbidities Compared With That in Controls Comparisons are shown among control subjects, patients with lone AF, and AF patients with comorbidities (p < 0.001). Post-hoc analyses show lone AF versus control (p = 0.015); AF with comorbidities versus control (p < 0.01); and AF with comorbidities versus lone AF (p = 0.031). AF = atrial fibrillation; *AM-Ref = age-matched reference group (see text); LA = left atrium; P = periphery; RA = right atrium. Han S. Lim et al. JACEP 2015;1:210-217 American College of Cardiology Foundation