Baseline and stimulated ANF plasma levels: is an impaired stimulus-response coupling diagnostically meaningful?

Plasma levels of ANF were determined and chromatographically analysed in normotensive controls, cirrhotic patients with and without ascites, hypertensive patients, patients with congestive heart failure and heart transplant recipients. A comparison of baseline plasma levels allowed for the conclusion that cirrhotic patients do not differ in this regard from control subjects (9.0 +/- 1.3, n = 41 vs. 9.6 +/- 1,0 fmol/ml, n = 51). Cirrhotic patients with ascites do not have lower plasma levels than cirrhotic patients without ascites (8.8 +/- 1.4, n = 8 vs 8.6 +/- 1.5 fmol/ml, n = 10). Stimulation of the ANF-system by head-out water immersion, however, revealed an impaired increase in ANF release in cirrhotic patients with ascites (146 +/- 18% vs 204 +/- 16%). Patients with cardiovascular disease display tonically-elevated ANF plasma levels. Heart failure patients displayed the highest plasma concentration (81.5 +/- 32.7 fmol/ml, n = 17), whereas plasma levels in hypertensive patients ranged from normal to greatly elevated (61.7 +/- 13.2 fmol/ml, n = 36). Heart transplant recipients also had significantly elevated plasma levels as compared to control subjects (31.2 +/- 7.9 fmol/ml, n = 14) but levels were lower than in hypertensive patients in spite of a comparable arterial pressure. Short term ventricular pacing (f = 150/min for 5 min) revealed an impaired phasic activity of the ANF system in heart failure patients and heart transplant recipients.(ABSTRACT TRUNCATED AT 250 WORDS)