The relationship between flow-mediated dilatation and left ventricular function (assessed by tissue Doppler echocardiography) in asymptomatic patients with mixed connective tissue disease

Objectives: The mixed connective tissue disease (MCTD) is a systemic inflammatory autoimmune disease, an overlap syndrome characterized by combinations of clinical features of systemic lupus erhytematous, systemic sclerosis, polymiositis and rheumatoid arthritis and the presence of high titers of circulating of autoantibodies to nuclear RNP antigen. Cardiac involvement is a common finding in MCTD, but often clinically occult Aim of the study: To assess the relationship between flow-mediated dilatation (FMD) and left ventricular (LV) myocardial function in asymptomatic patients with overlap syndrome. Methods: 20 healthy patients and 37 asymptomatic patients with MCTD underwent immunological evaluation and tissue Doppler echocardiography-Early diastolic (Em), late diastolic Am), peak systolic (Sm) mitral annular velocities, Em/Am and the ratio of early diastolic mitral inflow velocity to Em (E/Em), calculated by tissue Doppler imaging (TDI). Endothelial function, measured as flow-mediated dilatation (FMD) of the brachial artery using ultrasound, was assessed in both groups. Results: Endothelial flow-mediated dilatation was significantly lower in MCTD patients (P<0.001) In TDI examination no significant difference between the groups in systolic myocardial velocity was found. In MCTD patients LV myocardial early diastolic peak velocity was reduced than in controls and mitral annular isovolumetric relaxation time was significantly increased (p<0.001) The detailed assessment of diastolic function in MCTD group showed severe diastolic dysfunction of longitudinal myocardial fibers with normal function of circumflex myocardial fibers. Conclusions: Tissue Doppler imaging and brachial artery flow-mediated dilatation are valuable noninvasive and easily repeatable tools for detecting LV myocardial and vascular involvement caused by MCTD. Their combined use may be therefore useful for early identifying patients with LV myocardial dysfunction, ideally in asymptomatic cases prior to the development of severe vasculopathy. In MCTD patients significant left ventricle diastolic dysfunction was found. Diastolic dysfunction was observed only in longitudinal myocardial fibres and was not found in circumflex myocardial fibres. Left ventricle diameter, walls thickness and systolic function in MCTD patients are preserved.