Correlation between atrial natriuretic peptide and baroreflex sensitivity in patients with congestive heart failure

The aim of this study was to investigate the relationship between barorefle x sensitivity (BRS) and humoral factors in patients with congestive heart f ailure (CHF). BRS was assessed by the phenylephrine method in 16 patients w ith CHF and in 13 healthy controls. The CHF group was subdivided into 2 gro ups according to BRS (group A: <6 ms/mmHg, n = 9; group B: greater than or equal to 6 ms/mmHg, n = 7). BRS was markedly depressed in CHF than in the c ontrols (4.8 +/- 2.0 vs 8.3 +/- 3.6 ms/mmHg, p < 0.01), and lower in group A than group B (3.3 +/- 1.3 vs 6.7 +/- 0.6 ms/mmHg, p < 0.01). The plasma h uman atrial natriuretic peptide (h-ANP) level in group A was significantly higher than in group B (54.6 +/- 27.6 vs 18.0 +/- 7.4 pg/ml, p < 0.01), and a significant inverse correlation was observed between plasma h-ANP and BR S (r = -0.635, p < 0.01). However, then were no significant differences bet ween the 2 groups in plasma catecholamine concentration, plasma renin activ ity and cardiac function by echocardiogram. These findings suggest that the elevation of endogenous ANP may also serve to compensate for impaired BRS in patients with CHF, in addition to its principal actions, such as diuresi s and vasodilation.