Previous studies have shown regression of left ventricular hypertrophy after pharmacologic treatment of hypertensive patients; however, the impact of regression of left ventricular hypertrophy on systolic function and on left and right ventricular diastolic function remains controversial and is difficult to assess because previous studies have not included concurrently studied age-matched control groups. Left ventricular mass, systolic function, and left and right ventricular diastolic function were assessed in 27 hypertensive patients, aged 43 +/- 6 years, by echocardiographic and Doppler studies before and 1, 3, 5, and 7 months after treatment. Left ventricular mass and ventricular function were concurrently evaluated in 27 age-matched normotensive subjects. Treatment with antihypertensive agents resulted in a significant (p < 0.001) reduction in diastolic blood pressure of 15 mmHg, measured at 1 month and sustained throughout the study. In response to hemodynamic unloading, left ventricular mass index decreased from 129 +/- 30 gm/m2 at baseline to 105 +/- 26 (p < 0.05) and 88 +/- 14 gm/m2 (p < 0.05) at 1 and 3 months of treatment, respectively, and remained unchanged over the subsequent 4 months. After 3 months of treatment, left ventricular mass index was similar in treated hypertensive and control subjects. Systolic function, assessed in terms of the relationship between shortening fraction and end-systolic wall stress, was unchanged throughout the treatment period and was no different from that in control subjects. However, patients with an initially depressed shortening fraction experienced a greater increase in shortening fraction during treatment compared to those with an initially normal shortening fraction (11% +/- 4% vs 5% +/- 5%, p < 0.01) and showed an improvement in the relationship between shortening fraction and end-systolic wall stress during treatment. Ventricular filling dynamics improved during the first 3 months of treatment, after which they were unchanged. Ventricular filling dynamics were similar in treated hypertensive patients and control subjects. In conclusion, sustained hemodynamic unloading of the left ventricle results in normalization of left ventricular mass, systolic function, and left and right ventricular diastolic filling dynamics, compared to those in age-matched control subjects.