Inconsistency in LVOT measurement between cardiac computed tomography, magnetic resonance imaging and 3D echocardiography

Abstract Funding Acknowledgements Type of funding sources: None. Background. As a rule, cardiac computed tomography (CT) and magnetic resonance imaging (MRI) are undertaken in the supine position, and in the majority of cases, the ideal position for echocardiography is the left lateral position with the left arm raised above the head. Changing the position of the body from supine to lateral shifts the apex of the left ventricle by 1.5 cm. At the same time, the base of the heart does not alter its position. We evaluated how altering body position can affect visualization of the left ventricular outflow tract (LVOT). Aim. The purpose of this study is to examine was whether the changing of body position modifies the shape of LVOT. Methods. The study enrolled 12 patients, 2 of them had aortic valve stenosis. All these patients underwent 3D echocardiography, for 5 patients cardiac computed tomography with intravenous contrast, and for 7 patients cardiac MRI was undertaken. The LVOT shape was assessed by measuring the long and short diameter and calculating its ratios. Results. On the lateral positioning of the body, there was not observed any changes in the short diameter of the LVOT by cardiac CT and 3D echocardiography. However, the large diameter of the LVOT by cardiac CT and MRI is 1.27± 0.09 mm. In addition, on the supine position, this ratio was 1.24± 0.08 mm, p < 0.005. Conclusion. An alteration in the shape of the LVOT, in particular, is due to the large diameter of the LVOT. The large diameter modifies the shape of LVOT without changing its area.