Speckle tracking echocardiographic assessment of left ventricular longitudinal strain in female patients with subclinical hyperthyroidism

BACKGROUND: Patients with subclinical hypothyroidism (SCH) are subjected to many cardiac changes. However, these changes are of gradual onset and cannot be usually detected using conventional diagnostic methods. Speckle tracking echocardiography (STE) is capable to detect cardiac function alterations usually unidentified by conventional echocardiography. The present study aimed to evaluate the role of STE in the detection of early cardiac changes in female patients with SCH. METHODS: The study included 33 female patients with SCH and 30 matched healthy volunteer women with normal thyroid functions who served as controls. Upon recruitment, all participants were subjected to careful history taking, thorough clinical examination and routine laboratory investigations, including thyroid-stimulating hormone and Free T4. The echocardiographic examination included conventional, color Doppler and two-dimensional STE. RESULTS: Analysis of conventional echocardiographic data revealed that patients had significantly higher end-systolic volume when compared with controls. In addition, it was noted that SCH patients had significantly lower mitral E/A ratio, isovolumetric relaxation time and significantly higher left atrium volume index in comparison to controls. In respect to STE data, we noted that patients had significantly lower values of mid-anteroseptal, apical lateral, apical septal, apical apex, AP4L strain and global strain % when compared with controls. CONCLUSIONS: Patients with SCH have deteriorated global strain in comparison to healthy controls.