Atrial natriuretic peptide in patients with heart failure and chronic atrial fibrillation: role of duration of atrial fibrillation.

The purpose of this study was to analyze the determinants of atrial natriuretic peptide level in patients with congestive heart failure and atrial fibrillation. In particular, the duration of atrial fibrillation was analyzed because atrial fibrillation per se might have a specific effect on atrial natriuretic peptide level. The study group consisted of 26 patients with mild to moderate stable congestive heart failure and chronic atrial fibrillation. Plasma samples of atrial natriuretic peptide were obtained at rest and were analyzed with radioimmunoassay. Median atrial natriuretic peptide level was 213 (range 42 to 438) ng/L. Multivariate determinants of atrial natriuretic peptide level were use of calcium antagonists and the duration of atrial fibrillation; both factors showed an inverse relation with atrial natriuretic peptide level. The finding that atrial natriuretic peptide level was lower among patients with atrial fibrillation of longer duration suggests a form of insufficiency of the atria to produce atrial natriuretic peptide because of degenerative changes in the atria inherent to chronic atrial fibrillation.