Subclinical hyperthyroidism and biatrial function and mechanics: a two- and three-dimensional echocardiographic study

Background We sought to evaluate left atrial (LA) and right atrial (RA) phasic function and deformation in the subclinical hyperthyroidism (SCH) using two- and three-echocardiographic (2DE and 3DE) methods. Methods We included 45 untreated women with SCH and 45 healthy women who underwent comprehensive 2DE and 3DE examination. Results Total and passive LA emptying fractions (EF) were decreased, whereas active EF was increased among the SCH participants. RA total EFs were similar between the controls and the SCH subjects; passive EF was reduced; and active EF was amplified in the SCH group. TSH correlated with 2DE LA passive and active EFs, 3DE LA total, passive and active EFs, as well as 2DE LA positive longitudinal strain. Additionally, TSH correlated with 2DE RA passive and active EFs, 3DE LA and RA passive EF, 2DE LA and RA positive longitudinal strain. However, after adjustment for the parameters of left and right ventricular diastolic function and structure, the TSH level remained associated only with LA conduit and booster pump functions, as well as RA pump function. Conclusion Biatrial phasic function evaluated by 2DE and 3DE is significantly impaired in the SCH subjects. TSH level correlates with LA and RA conduit and pump functions.