Cross-sectional analysis of electrocardiograms in a large heterogeneous cohort of Friedreich ataxia subjects.

Electrocardiographic (ECG) findings in Friedreich ataxia and their relation to disease characteristics have not been well described. In this retrospective cross-sectional study, the authors reviewed baseline ECGs from 239 children and adults with Friedreich ataxia. ECG abnormalities--assessed in relation to participant age, sex, shorter guanine-adenine-adenine triplet repeat length, age of disease onset, and functional disability score--were found in 90% of subjects, including nonspecific ST-T wave changes (53%), right axis deviation (32%), left ventricular hypertrophy (19%), and right ventricular hypertrophy (13%). Female sex and shorter guanine-adenine-adenine repeat lengths were associated with a normal ECG (P = .004 and P = .003). Males and those of younger age were more likely to show ventricular hypertrophy (P = .006 and P = .026 for left ventricular hypertrophy and P < .001 and P = .001 for right). Neurologic status as measured by the functional disability score did not predict ECG abnormalities.