Cardiac 3,4-dihydroxyphenylethylene glycol (DHPG) and catecholamine levels during perindopril therapy of chronic left ventricular failure in rats.

1. Left ventricular myocardial infarction was induced in female Wistar rats by ligation of the left anterior descending coronary artery. 2. One month following operation, rats with infarcts developed marked cardiomegaly compared to sham operated rats, indicating the presence of chronic left ventricular failure. 3. The ratio of the noradrenaline metabolite 3,4-dihydroxyphenylethylene glycol (DHPG) to noradrenaline (NA) was elevated in the right ventricle of rats with heart failure one month following infarction, suggesting a chronic increase in cardiac sympathetic activity. 4. Perindopril therapy for one month commenced 4 weeks after infarction returned cardiac weights to normal and significantly reduced right ventricular DHPG/NA ratios. 5. The results suggest that ACE inhibition with perindopril reduces elevated levels of cardiac sympathetic activity in rats with chronic left ventricular failure and leads to regression of cardiomegaly.