Although heart involvement has been widely reported in Friedreich's ataxia (FA), which is the most prevalent of the spino-cerebellar degenerative diseases, the reason that cardiac abnormalities develop has not been yet established. The investigation was undertaken to study the prevalence and characteristics of cardiac abnormalities in patients with FA and to evaluate whether the presence of left ventricular hypertrophy could be predicted. In all, 75 patients with FA and 16 patients with late onset FA (LOFA) disease were investigated for cardiac abnormalities using noninvasive methods. A significant (p < 0.01) difference in the age onset (9.8 +/- 3.9 years) was found in 31 of the 75 patients with FA (41%) who showed left ventricular hypertrophy (LVH) at echocardiographic examination compared with the remaining 44 patients with FA without LVH (12.6 +/- 4.3 years). Moreover, none of the 16 patients with LOFA (age onset 26.5 +/- 4.2 years) showed abnormalities at echocardiographic examination. A significant (p < 0.01) concordance in the familial distribution of hypertrophy was also found. These data suggest that the earlier the disease develops the more frequently LVH occurs.