Torsion Mechanics as an Indicator of More Advanced Left Ventricular Systolic Dysfunction in Secondary Mitral Regurgitation in Patients with Dilated Cardiomyopathy: A 2D Speckle-Tracking Analysis

Abstract

Left ventricular (LV) twist serves as a compensatory mechanism in systolic dysfunction and its degree of reduction may reflect a more advanced stage of disease. Aim: The aim was to investigate twist alterations depending on the degree of functional mitral regurgitation (MR) by speckle-tracking echocardiography. Methods: Sixty-three patients with symptomatic dilated cardiomyopathy (DCM) were included. Patients were divided according to MR vena contracta width (VCW): group 1 with VCW <7 mm (mild/moderate MR) and group 2 with VCW ≥7 mm (severe MR). Results: There were no differences in LV geometry and function between groups. Group 2 showed lower endocardial basal rotation (BR) (–2.04° ± 1.83° vs. –3.23° ± 1.83°, p = 0.012); epicardial BR (–1.54° ± 1.18° vs. –2.31° ± 1.22°, p = 0.015); endocardial torsion (0.41°/cm ± 0.36°/cm vs. 0.63°/cm ± 0.44°/cm, p = 0.033) and mid-level circumferential strain (CSmid) (–6.12% ± 2.64% vs. –7.75% ± 2.90%, p = 0.028), when compared with group 1. Multivariable linear regression analysis identified endocardial BR, torsion and CSmid, as the best predictors of larger VCW. In the ROC curve analysis, endocardial BR and CSmid values greater than or equal to –3.63° and –9.35%, respectively, can differentiate patients with severe MR. Conclusions: In DCM patients, torsional profile was more altered in severe MR. Endocardial BR, endocardial torsion, and CSmid, can be used as indicators of advanced structural wall architecture damage.