Valutazione della funzione cardiaca nei pazienti affetti da Atassia di Friedreich: studio con Tissue Doppler Imaging e Speckle Tracking Echocardiography

Background. Friedreich ataxia (FRDA) is an autosomal recessive degenerative disease characterized by progressive gait and limb ataxia, hypertrophic cardiomyopathy, diabetes and sensory neuropathy. Large GAA repeat expansions in the first intron of the frataxin gene are the most common mutation underlying FRDA. This mutation results in intramitochondrial iron accumulation and oxidative stress increase. FRDA is associated with progressive cardiac hypertrophy; however, subclinical left ventricular (LV) dysfunction may occur in FRDA patients in spite of normal LV ejection fraction (LVEF) and mass. Moreover cardiac sudden death is the most common cause of exitus in these patients. Methods. We enrolled 5 FRDA patients (age: 39.8 ± 19.05 years; 2F and 3M) free of cardiovascular risk factors and 5 sex- and age-matched healthy subjects (age 32.75 ± 6.22 years); they underwent to clinical evaluation, standard echocardiography with Tissue Doppler, 2D and 3D Speckle Tracking. Results. No significant differences were identified in terms of anthropometric characteristics and cardiovascular risk profile between the two groups. All echocardiographic standard parameters, including LV dimensions, LV mass, LVEF and E/E’ ratio resulted in the normal range, in absence of significant differences between patients and healthy subjects. On the other hand, we found a reduction in Global Longitudinal Strain (GLS; 10.93 ± 1.72 % vs 15.92 ± 1.17%, p= 0.003), as already reported in literature. Moreover we compared values of longitudinal strain of LV basal and apical segments between the two groups, thus identifying a significant impairment of apical regions in FRDA patients (10.12 ± 3.48 % vs 18.7 ± 2.57, p =0.02). Conclusions. Our data seem to suggest that the observed reduction in GLS could be due to a segmental impairment of systolic function at apical level. This finding could be explained by the sympathetic denervation reported in other forms of neurodegenerative disorders, such Parkinson’s disease and Multiple sclerosis.