Plasma levels of nitrites/nitrates in patients with chronic atrial fibrillation are increased after electrical restoration of sinus rhythm

Patients with persistent atrial fibrillation (AF) have hemodynamic changes, which impair endothelial cell function resulting in decreased nitric oxide (NO) production. The aim of this work was to assess endothelial function in AF patients before and at various time points after cardioversion. Forty-two patients with AF and 21 normal and age-adjusted healthy controls were studied. Nitrites and nitrates (NO(x)) and von Willebrand factor (vWf) concentrations were measured on blood samples taken just before cardioversion and over a 30 day period after the procedure. Plasma levels of NO(x) in AF were significantly lower compared to healthy controls (p < 0.001), but after cardioversion gradually increased to approach to those of the healthy controls by the end of the first month of sustained sinus rhythm (p = 0.004). Interestingly plasma levels of NO(x) were negatively correlated to left atrial volume measured by ultrasonography (r = -0.34, p < 0.05). Plasma levels of vWf in AF patients were significantly higher compared to the healthy controls (p < 0.01) but with sustained sinus rhythm decreased (p = 0.02). The parallel normalization of the NO(x) titers and vWf levels suggests that vascular endothelial function improves after 30 days of normal sinus rhythm.