Aims The purpose of this study was to examine, in chronically treated heart failure patients vs control subjects, the influence of neurohumoral activation and aldosterone escape on arterial elastic behaviour, assessed by non-invasive mathematical lumped-parameter modelling of the compliance of the arterial system. Methods and Results Radial arterial pulse waves were recorded non-invasively for 30s with an arterial tonometer sensor array in 13 chronic heart failure patients (mean age, 59±2·5 years) in New York Heart Association class II. The patients had been taking digoxin, furosemide, captopril and aspirin for more than 3 months. Thirteen healthy subjects (mean age, 50±4·0 years) acted as controls. Compliance of the proximal (aorta and major branches, C1) and distal parts (C2) of the circulation were derived from a third order four-element modified Windkessel model which can reproduce arterial pressure waveforms, including both exponential and oscillatory sections. Active renin, angio-tensin II and aldosterone levels were determined on venous blood samples in the supine position and after 30min active standing. There was decreased proximal (C1, 1·51±0·11ml.mmHg−1,P−1) arterial compliance in the chronic heart failure patients vs controls (C1, 1·71±0·16ml.mmHg−1; C2, 0·054±0·006ml.mmHg−1). The chronic heart failure patients were characterized by an aldosterone escape phenomenon which was inversely correlated with the proximal arterial compliance in both supine (r=−0·795,P=0·002) and standing (r=−0·628,P=0·029) positions. Conclusions In chronically treated heart failure patients with full angiotensin-converting enzyme-inhibition and diuretics, there is decreased compliance of the aorta and its major branches, which is inversely correlated with the aldosterone escape phenomenon.