Early changes in left ventricular long-axis function in Friedreich ataxia: Relation with the FXN gene mutation and cardiac structural change

Abstract

Objective: Friedreich ataxia (FRDA) is an autosomal recessive condition due to a GAA triplet expansion in the FXN gene that causes increased left ventricular (LV) wall thickness and can progress to LV systolic dysfunction. However, the changes in myocardial function that occur before a reduction in LV ejection fraction are incompletely understood. Methods: LV long-axis function was assessed by measurement of tissue Doppler imaging (TDI) peak systolic (S'), early diastolic (E'), and atrial velocities (A') at the septal and lateral borders of the mitral annulus in 60 subjects homozygous for a GAA expansion in the FXN gene who had preserved LV ejection fraction. Comparison was made with 60 sex-..