Cardiac aspects of Friedreich's ataxia.

FRIEDREICH 'S ATAXIA is one of the rare heritable spinocerebellar degenerations. The spinocerebellar tracts, dorsal columns, pyramidal tracts, and, to a lesser extent, the cerebellum and medulla are involved. The disorder is usually manifest before adolescence and is generally characterized by incoordination of limb movements, dysarthria, nystagmus, diminished or absent deep tendon reflexes, Babinski's sign, impairment of position and vibration sense, scoliosis, pes cavus, and hammer toe. Some of these signs may be absent, particularly early in the course of disease. A variety of other findings, for example, optic atrophy, nerve deafness, appear in a minority of patients. The triad of hypoactive knee and ankle jerks, evidence of progressive cerebellar dysfunction, and pre-adoleseent onset is commonly regarded as sufficient for diagnosis. Cardiac disturbances were mentioned by Friedreich in his account of 1863.1 Although Pitt2 and Saury3 emphasized these features they were generally unnoticed until Mollaret described electrocardiographic abnormalities in 1929.4 Thereafter many reports appeared in the European literature and, up to 1938, were summarized by Loiseau.5 Evans and Wright6 examined the 3and 4-lead electrocardiogram of 38 patients with Friedreich's ataxia and found it abnormal in 12. None of their patients had an enlarged heart or a cardiac murmur. Subsequent reports, each on comparatively few patients, have continued to note electrocardiographic changes7-12 and,