To determine factors contributing to abnormal left ventricular (LV) diastolic filling in patients on long-term continuous ambulatory peritoneal dialysis (CAPD), 11 (age: 55 +/- 13 years; CAPD duration: 33 +/- 32 months) out of 42 originally studied CAPD patients were followed over 35 months with echocardiography and pulsed Doppler echocardiography. LV dimensions and systolic function remained normal. Doppler parameters indicated diastolic LV dysfunction in 9/11 patients in the initial study. Despite a significant increase in LV mass (234 +/- 54 vs. 299 +/- 65 g; p < 0.05) and a decrease in LV volume/mass ratios (0.78 +/- 0.18 vs. 0.54 +/- 0.12 ml/g; p < 0.001), no change was observed in any of the diastolic LV filling parameters such as peak early and atrial filling velocities and their ratios, atrial filling fractions and peak filling rate normalized for mitral stroke volume. Individual changes of E/A-max were inversely correlated with systolic blood pressure (p < 0.01), alterations of normalized peak filling rate were inversely correlated with serum creatinine (p < 0.01). No influence on individual changes of LV diastolic filling parameters was observed for LV volume, muscle mass, volume/mass ratios, ejection fractions, patient age, dialysis duration, and hemoglobin concentration. These findings suggest that arterial hypertension and the quality of blood purification play a central role in the development of LV diastolic dysfunction in patients on CAPD, while LV muscle mass and LV volume/mass relations have no relevant influence on changes of LV diastolic function in these patients.