Differences in blood pressure regulation of congestive heart failure, before and after treatment, correlate with changes in the circulating pattern of atrial natriuretic peptide.

Abstract

The mechanisms underlying altered BP regulation in congestive heart failure are unknown. This study examines the possibility that differences in circadian blood pressure (BP) regulation between the normal and the failing heart correlate with changes in the circulating pattern of atrial natriuretic peptide (ANP). Twelve normotensive patients with coronary artery disease were studied over two separate 24-h periods, the first during acute exacerbation of congestive heart failure (radionuclide-determined ejection fraction at rest was less than 30%) and the second after therapy-induced functional recovery (ejection fraction was more than 40%). BP monitoring at 10-min intervals and intra-atrial blood samples for ANP assays at hourly intervals were obtained. Significant correlation between ejection fraction and the indexes of circadian BP variability (standard deviation of the 24-h pressure mean and day-night pressure difference) were found both before and after treatment. Ejection fraction was independent of the BP means (24-h, daytime and night-time). BP variability, 24-h mean and daytime mean were higher after treatment. ANP means were lower after treatment, whereas ANP variability was higher. The indexes of BP and ANP variability correlated both before and after treatment, whereas the BP and the ANP means were independent. These findings demonstrate that differences in BP regulation of CHF before and after effective treatment correlate with changes in the circulating pattern of ANP. We speculate that by modulating ANP release, the heart could be actively involved in BP regulation as part of the compensatory mechanisms aimed at protecting against circulatory overload.