Cardiovascular disease is the major cause of mortality in maintenance hemodialysis patients. Left ventricular dysfunction is present in approximately 80% of these patients and is highly predictive of future ischemic heart disease, cardiac failure, and death. Anemia has been identified as one of several risk factors responsible for cardiac complications. The treatment of renal anemia with recombinant human erythropoietin (rHuEpo) and consequent improvement of cardiac performance may reverse pathological changes in left ventricular geometry. In this study, the acute and chronic effects of rHuEpo administration on 24-hour ambulatory blood pressure recordings and echocardiographic parameters in 30 rHuEpo-naïve maintenance hemodialysis patients were examined. Twenty-four-hour ambulatory blood pressure monitoring was performed prior to and after 1 week and 6 months of rHuEpo administration. The patients underwent echocardiographic examination prior to and after 6 months of rHuEpo administration. One week treatment with rHuEpo did not cause any significant change in 24-hour ambulatory blood pressure recordings. After 6 months of therapy, serum hemoglobin levels increased from 8.8 +/- 0.66 g/dL to 10.8 +/- 0.70 g/dL (P < 0.05). Echocardiographic examination revealed elevation in ejection fraction (62.26 +/- 6.84% vs. 69.90 +/- 8.98%, P < 0.05) with reductions in fractional shortening (36.70 +/- 4.96% vs. 35.96 +/- 6.32%, P < 0.05), interventricular septum thickness (1.21 +/- 0.16 vs. 1.00 +/- 0.16 cm, P < 0.05), and left ventricular mass index (148.2 +/- 46.5 g/m2 vs. 93.6 +/- 17.2 g/m2, P < 0.05). Doppler echocardiography and tissue Doppler imaging provided additional information in comparison with conventional echocardiography. Before treatment, mitral flow E wave (E, 0.64 +/- 0.27 vs. 0.82 +/- 0.17 cm/s), mitral flow A wave (A, 0.80 +/- 0.21 vs. 0.70 +/- 0.21 cm/s), early diastolic velocity of lateral wall (Lateral E', 11.2 +/- 2.8 vs. 12.4 +/- 2.3 cm/s), late diastolic velocity of lateral wall (Lateral A', 6.7 +/- 2.5 vs. 7.8 +/- 2.1 cm/s), early diastolic velocity of septal wall (Septal E', 9.7 +/- 2.9 vs. 11.3 +/- 1.1 cm/s), and late diastolic velocity of septal wall (Septal A', 6.4 +/- 2.1 vs. 7.8 +/- 2.0 cm/s) were significantly lower in patients than in the controls. Patients and controls have similar deceleration time of mitral flow E wave (E Dec, 186 +/- 57.8 vs. 192 +/- 62.4 ms), isovolumic left ventricular relaxation time (IVRT, 111.9 +/- 30.7 vs. 91.1 +/- 32 ms), systolic velocity of lateral wall (Lateral S', 7.8 +/- 2.3 vs. 8.1 +/- 2.0 cm/s), and systolic velocity of septal wall (Septal S', 7.5 +/- 1.9 vs. 7.7 +/- 1.4 cm/s) values. Therapy with rHuEpo did not cause significant changes in E (0.64 +/- 0.27 vs. 0.76 +/- 0.29 cm/s), A (0.80 +/- 0.21 vs. 0.79 +/- 0.23 cm/s), E Dec (186 +/- 57.8 vs. 165.8 +/- 60.1 ms), IVRT (111.9 +/- 30.7 vs. 101.6 +/- 36.2 ms), Lateral E' (11.2 +/- 2.8 vs. 11.5 +/- 4.4 cm/s), Lateral A' (6.7 +/- 2.5 vs. 7.4 +/- 2.1 cm/s), Lateral S' (7.8 +/- 2.3 vs. 8.1 +/- 2.0 cm/s), Septal E' (9.7 +/- 2.9 vs. 10.0 +/- 1.1 cm/s), Septal A' (6.4 +/- 2.1 vs. 6.6 +/- 2.0 cm/s), and Septal S' (7.5 +/- 1.9 vs. 7.9 +/- 1.4 cm/s) indicating persistence of diastolic dysfunction. In 6 months time, 24-hour ambulatory blood pressure recordings, however, tended to be higher (systolic: 125.16 +/- 21.02 mm Hg vs. 134.36 +/- 23.98 mm Hg; diastolic: 77.40 +/- 14.47 mm Hg vs. 83.26 +/- 14.89 mm Hg, P < 0.05). Correction of anemia with rHuEpo results in the elevation of blood pressure and reduction in left ventricular mass index. Myocardial contraction and relaxation velocities did not improve following regression of left ventricular hypertrophy, suggesting the persistance of diastolic dysfunction. Doppler echocardiography with tissue Doppler imaging reflects the real situation of diastolic function in patients on maintenance hemodialysis.