Abstract 16740: Myocardial Dysfunction in Patients with Friedreich Ataxia, Normal Left Ventricular Ejection Fraction and Mass
Introduction: Myocardial involvement in Friedreich Ataxia (FA) is characterized by iron deposits, diffuse fibrosis and focal necrosis. We hypothesized that subclinical left ventricular (LV) dysfunction might occur in patients with Friedreich ataxia who present with normal LV ejection fraction (LVEF) and mass.
Methods: Nineteen patients with FA who were homozygous for the GAA expansion in the FA gene (mean age: 35±16 years) and nineteen age- and gender -matched healthy controls (mean age: 35±15 years) were submitted to standard echocardiography. Myocardial deformation measurements were performed using speckle tracking imaging. LV peak systolic circumferential strain was averaged from basal, mid and apical short axis views. LV twist was defined as the net difference between the apical and basal rotation. LV peak systolic longitudinal strain was calculated from the apical 2-, 3- and 4-chamber views.
Results: The two groups did not differ in terms of LVEF (68±6% and 66±6% in patients and in controls, respectively). A slightly higher LV mass index was observed in the patient group (93±19 g/m2 versus 81±17 g/m2, p=NS). The LV filling parameters did not differ between the 2 groups. However, early diastolic mitral annular velocity (Ea) was lower and the ratio of early transmitral flow velocity to Ea was higher in FA patients (table). Peak LV twist, global systolic circumferential strain (GSCS) and global systolic longitudinal strain (GSLS) were significantly reduced in patients as compared to controls. Early diastolic LV untwisting (at 5%, 10% and 15% of diastole) was not significantly different.
Conclusions: In patients with FA, assessment of LV twist, GSCS and GSLS could potentially detect impaired myocardial function when LEVF and mass are still normal. These parameters may prove useful as an outcome measure for the assessment and follow-up of new therapies in the early stages of the disease.
- © 2010 by American Heart Association, Inc.