The Changes Of Aldosterone Level In Blood And Atrial Tissue After The Reversion Of Atrial Fibrillation To Sinus Rhythm In The Goat

Objective: To investigate the changes of aldosterone level in blood and atrial tissue when atrial fibrillation (AF) has been converted to sinus rhythm.Methods: 18 goats were randomly divided into 3 groups (each n=6): (1) sinus rhythm (group A); (2) AF (group B); (3) sinus rhythm after AF reversion (group C). All goats in each group were undergone open chest surgery to implant the pacemaker electrode into left auricle. Goats in group B and C were given continuous and rapid pacing (400±10 bpm) in order to create AF model, while goats in group A not. Three months later, goats in group A and B were all killed with their left and right atrial myocardium reserved. Goats in group C were stopped pacing and converted into sinus rhythm by propafenone and/or direct current. After three months' sinus rhythm, goats in group C were killed with atrial myocardium reserved as well. Serum samples were respectively taken in goats of group C at different periods: pre-pacing, 3 months post-pacing, 2 weeks, 1 month, 2 months, 3 months after AF reversion to sinus rhythm. Atrial aldosterone level was studied by enzyme-linked immunosorbent assay (ELISA) and serum aldosterone level was tested by radioimmunoassay.Results: The aldosterone level in atrial tissue decreased significantly in cardioversion group as compared with that in AF group (P=0.003), but with no marked differences from that in sinus rhythm group (P=0.247). It was found to be no difference between left atria and right atria in each group (P=0.149). The serum aldosterone level decreased gradually after the restoration of sinus rhythm.Conclusions: The aldosterone level in blood and atrial tissue decreased after AF reversion to sinus rhythm.