['Lipid peroxidation generates several unsaturated aldehydes, such as 4-OH-nonenal (HNE), which may interact with and modify the function of other molecules that are of biological importance. Although congestive heart failure (CHF) is a state of generalized oxidative stress, the resultant spectrum of saturated and unsaturated aldehydes has not been systematically characterized in this condition.', 'We studied 8 CHF patients and 8 age-matched patients with normal left ventricular (LV) function. The concentrations of 22 aldehydes produced by lipid peroxidation, including saturated (n-alkanals) and unsaturated (t-2-alkenals, t-2,t-4-alkadienals, 4-OH-alkenals) aldehydes, were measured in arterial plasma by gas chromatography mass spectrometry (GC/MS). LV contractility (+dP/dt) and relaxation (Tau) were directly measured with a micromanometer-tipped catheter.', 'Compared with patients who have normal LV function, CHF patients had higher levels of total aldehydes (9,311 +/- 835 v 6,594 +/- 344 nmol/L, P < .01), as well as multiple unsaturated aldehydes (t-2-alkenals and 4-OH-alkenals, including HNE). In the CHF group, a strong relationship was observed between total aldehyde concentration and both +dP/dt (correlation coefficient = -0.76, P < .05) and Tau (correlation coefficient = 0.78, P < .05).'] Are unsaturated aldehydes including 4-OH-nonenal elevated in patients with congestive heart failure?