ALTERNATIONS IN ATRIAL-NATRIURETIC-PEPTIDE RELEASE AFTER DC CARDIOVERSION OF NONVALVULAR CHRONIC ATRIAL-FIBRILLATION

The response of atrial natriuretic peptide (ANP) release to haemodynamic influences after cardioversion of atrial fibrillation has not been fully examined. We measured plasma concentrations of ANP and assessed haemodynamic changes 60-120 min after DC cardioversion in 22 patients with non-valvular chronic atrial fibrillation. Passive leg elevation to enhance volume expansion was performed 60 min after DC cardioversion. Sinus rhythm was restored in 18 of the 22 patients (successful DC cardioversion group). The control group consisted of seven patients with non-valvular chronic atrial fibrillation who did not undergo DC cardioversion (atrial fibrillation control group). In the successful DC cardioversion group, the mean pulmonary artery wedge wedge pressure decreased significantly 15 min after cardioversion (P<0.05) and then remained unchanged. Plasma concentrations of ANP also decreased significantly 15 min after cardioversion (P<0.05). Furthermore, there was an additional significant decrease in ANP levels for up to 60 min after cardioversion (P<0.05 from 15 min). Passive leg elevation for 15 min led to an increase in the mean pulmonary artery wedge pressure (P<0.01) and right atrial pressure (P<0.05), but did not result in increased plasma concentrations of AHP (47.1 +/- 27.6 vs 43.9 +/- 34.4 pg . ml(-1), mean +/- SD, P=ns). In the atrial fibrillation control group, passive leg elevation increased the mean pulmonary artery wedge pressure (P<0.01), the mean right atrial pressure (P<0.05) and plasma concentrations of ANP (139.9 +/- 85.8 vs 168.1 +/- 108.2, P<0.05). In summary, after successful DC cardioversion of non-valvular chronic atrial fibrillation, plasma concentrations of ANP decreased in conjunction with decreased mean pulmonary artery wedge pressure. The response of ANP release to volume expansion expansion, however, appears to be dysregulated in this patient population.