Acute increase in right atrial pressure by intracardiac stimulation releases atrial natriuretic peptide

Abstract

We studied the effect of an increase in heart rate and/or in right atrial pressure (RAP) on the release of at rial natriuretic peptide (ANP) in 18 patients. In group 1 (n = 6), right ventricular stimulation (100, 120, 140 and 150 bpm) was used to increase RA P by asynchronous contraction of the right atrium and ventricle. Mean RA P increased from 3.9 ±0.2 to 8.3±0–6mmHg (mean±SEM). Median ANP levels increased from 120 to 440pgml⁻¹ (P−1 (P < 0.05). In group 3 (n - 6), RA P or ANP were not influenced by continuous right atrial stimulation at 110 bpm. Plasma cyclic GMP levels paralleled the changes in plasma ANP. Thus, an acute increment of RAP results in a release of ANP, but acceleration of heart rate alone has no effect on ANP secretion.