Breath isoprene in patients with heart failure

Background: Chronic heart failure (CHF) is characterised by increased vascu lar resistance. This increased after load on the left ventricle contributes to the vicious cycle that leads to progression of myocardial failure, mult iple organ failure and death. There is evidence for increased oxidative str ess in heart failure, which will influence the myocardium but also peripher al vasculature endothelium. Aims: The aim of the present study was to exami ne the production of isoprene, reputed to reflect oxidative stress, in pati ents with CHF compared to control subjects. Methods: Twelve patients with C HF and thirty-one healthy control subjects free from heart disease were stu died. Breath was collected via a two-way non-re-breathing valve into a 60-1 gas collection bag. A sample of ambient air was collected at the same time . A measured aliquot of patient breath and ambient air (approx. 1.5 l) was adsorbed onto a gas adsorption tube packed with poropak-Q. Isoprene was mea sured using GC/MS and the production rate calculated. All samples of breath were collected at 10.00 It after subjects had been sitting at rest for 15 min. Results: Breath isoprene production in subjects with CHF was significa ntly reduced compared to controls 83(23) vs. 168(20) pmol min(-1) kg(-1). C onclusion: Breath isoprene does not directly reflect oxidative stress in CH F. (C) 2001 European Society of Cardiology. All rights reserved.