Cardiomyopathy in Friedreich's ataxia: a Doppler-echocardiographic study

Heart involvement is frequent in Friedreich's ataxia (FA), the most prevalent of the spino-cerebellar degenerative diseases, which is inherited with an autosomal recessive pattern. However, the pathophysiological link between cardiac and neurological disorders is not yet clearly established. We compared a group of 10 patients with FA to a control group (C) of 16 normal subjects, using Doppler-echocardiography. To see whether cardiac involvement was specific to FA, the data of patients with FA were also compared to those of patients with autosomal dominant olivo-ponto-cerebellar atrophia (OPCA), another spino-cerebellar degenerative disease. There was an increase in left ventricular mass index in FA (154 +/- 9 g.m-2 vs 99 +/- 7 g. m-2 in C, P < 0.001), systolic function was normal, the ejection fraction (EF) slope and E/A ratio were decreased (85 +/- 9 mm.s-1 vs 130 +/- 7 mm.s-1 in C, P < 0.001 and 1.5 +/- 0.1 vs 1.7 +/- 0.1 in C, P < 0.01, respectively), while the isovolumic relaxation period was increased (96 +/- 3 ms vs 92 +/- 2 ms in C, P < 0.01). Deceleration time and time-velocity integrals of A wave to total mitral flow were not modified. In OPCA only the E/A ratio was decreased (1.5 +/- 0.1 vs 1.7 +/- 0.1 in C, P < 0.05). These data show the presence of cardiomyopathy in FA with left ventricular hypertrophy and suggest the presence of diastolic function abnormalities. The cardiomyopathy seems specifically associated with FA and not to spino-cerebellar degenerative disease in general.