Catecholamines, renin-angiotensin-aldosterone system, and atrial natriuretic peptide at rest and during submaximal exercise in patients with congestive heart failure

Abstract

The aim of this study was to determine the responses of plasma catecholamines, renin-angiotensin-aldosterone (RAA) activity, and plasma atrial natriuretic peptide (ANP) to exercise in patients with congestive heart failure (CHF). Cardiac and neurohormonal responses were assessed during submaximal treadmill exercise testing in 23 patients with CHF (New York Heart Association classes I-III) and 13 control subjects (without CHF). Plasma norepinephrine, epinephrine, renin activity (PRA), angiotensin II (ATII), aldosterone, and ANP were measured at rest and immediately after exercise. Exercise duration was shorter in patients with CHF (control, 10.4 +/- 0.9 minute; CHF, 6.2 +/- 0.7 minute; P < 0.01). Heart rate and blood pressure responses were similar except for the smaller peak heart rate (control, 145 +/- 5 beats per minute; CHF, 129 +/- 4 beats per minute; P < 0.05) and higher systolic blood pressure at recovery stage (control, 122 +/- 4 mm Hg; CHF, 142 +/- 4 mm Hg; P < 0.01) in patients with CHF. At rest, plasma norepinephrine levels were insignificantly higher in patients with CHF (control, 110 +/- 10 pg/mL; CHF, 170 +/- 26 pg/mL; P = 0.09), and ANP levels (control, 40 +/- 5 pg/mL; CHF, 94 +/- 17 pg/mL; P < 0.05) and PRA levels (control, 0.77 +/- 0.11 ng/mL/hr; CHF, 4.33 +/- 1.25 ng/mL/hr; P < 0.05) were significantly higher. There were no differences in peak norepinephrine, epinephrine, or ANP between the two groups. Angiotensin II and aldosterone levels were similar between the two groups, although, in patients with CHF, there was a trend toward higher levels of ATII while at rest (control, 12.4 +/- 1.4 pg/mL; CHF, 20.3 +/- 3.3 pg/mL; P = 0.08) and at peak (control, 20.5 +/- 1.8 pg/mL; CHF, 41.0 +/- 9.4 pg/mL; P = 0.10). Peak values of PRA, ATII, and aldosterone positively correlated with respective resting values of PRA (r = 0.88 ng/mL/hr, P < 0.01), ATII (r = 0.63 pg/mL, P < 0.01), and aldosterone (r = 0.99, P < 0.01). Peak norepinephrine and peak ANP also positively correlated with respective resting values of norepinephrine (r = 0.58 pg/mL, P < 0.05) and ANP (r = 0.94, P < 0.01). Analysis of these results showed that patients with CHF had significantly higher levels of PRA and ANP at rest, and a trend toward augmentation in RAA system activity during exercise with less exercise workload. Basal level of neurohormones seemed to be an important determinant for the degree of exercise-induced neurohormonal activation in patients with CHF.