Long-term hemodialysis has been reported to cause progression of left ventricular (LV) hypertrophy with a tendency toward asymmetric septal hypertrophy. Renal transplantation is believed to reverse some of these changes. The aim of this prospective study was to compare the effects of long-term hemodialysis and of successful renal transplantation on cardiac structure and function assessed by echocardiography. Fifty-three patients were submitted to two echocardiographic evaluations separated by a 30 +/- 8 month interval. At the first control, all patients were on hemodialysis; at the second, 36 patients remained on dialysis while 17 had been submitted to renal transplantation. Age (44 +/- 13 vs. 40 +/- 10 years), gender (male, 50% vs 53%), and duration of dialysis at the initiation of the study (43 +/- 34 vs. 47 +/- 32 months) were comparable in the 2 groups. The prevalence of LV hypertrophy were 83% (first control) and 69% (second control) in the dialysis group and 82% and 71% in the transplant group. Comparisons between the two periods within each group showed that hemodialysis was associated with a significant reduction of the E/A ratio (1.25 +/- 0.4 vs. 1.02 +/- 0.4, p < 0.001) and systolic (155 +/- 28 vs. 137 +/- 26 mm Hg, p < 0.001) and diastolic (94 +/- 21 vs. 84 +/- 16 mm Hg, p < 0.05) blood pressure, and no change in LV mass index (171 +/- 51 vs. 156 +/- 43 g/m2, NS). In the transplanted group, there were reductions in the E/A ratio (1.42 +/- 0.6 vs 1.10 +/- 0.4, p < 0.05) and in LV diastolic dimension (50 +/- 7 vs. 46 +/- 5 mm, p < 0.05), but not in systolic (155 +/- 27 vs. 152 +/- 31 mm Hg, NS) or diastolic (97 +/- 11 vs. 97 +/- 20 mm Hg, NS) blood pressure. The LV mass index also did not change significantly (157 +/- 51 vs. 133 +/- 31 g/m2, NS).(ABSTRACT TRUNCATED AT 250 WORDS)