Enalopril treatment (20 mg every 12 hours) of 24 patients with essential hypertension and left ventricular (LV) hypertrophy established normal blood pressure (BP) after 8 weeks, and after 7 years had reduced LV mass index by 39% from 148 +/- 34 to 90 +/- 16 g/m2, and had normalized LV structure and function and QT dispersion. Stepwise reduction of the enalapril dosage from 40 to 30, 20, 10, and 5 mg/day during the eighth year caused no significant changes in BP, LV structure, LV systolic function, or QT dispersion, which all likewise remained unaltered during a further year of the 5-mg/day regimen. We conclude that for hypertensive patients in whom prolonged treatment with standard doses of enalapril has normalized BP, LV structure and function, and QT dispersion, significantly smaller doses are sufficient to maintain these cardiovascular achievements.