Ultrasound Study of Layer-specific Strain and Perfusion of Left Ventricular Myocardium in Patients With Dilated Cardiomyopathy

Abstract

BackgroundTo investigate the changes in deformation and myocardial microcirculation perfusion of left ventricular three-layer myocardium in patients with dilated cardiomyopathy (DCM) by using speckle tracking imaging (STI) and myocardial contrast echocardiography (MCE).MethodsTwenty-four patients with DCM and 19 healthy controls were selected. Two-dimensional and MCE dynamic images of apical four-chamber, two-chamber, and three-chamber sections and left ventricular mitral valve, papillary muscle and apex sections were collected. The peak values of longitudinal strain (LS), circumferential strain (CS), cross-sectional area of a microvessel (A) and average myocardial microvascular lesion (β) were obtained by Qlab 10.8 workstation values, and myocardial blood flow (MBF) was calculated with A×β to evaluate the deformation and coronary microvascular perfusion of left ventricular three-layer myocardium.ResultsThe brain natriuretic peptide (BNP), left ventricular mass index (LVMI), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVEDS), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left atrial volume index (LAVI), E peak in early diastolic period/A peak velocity in late diastolic period (E/A) and average E/e' in the DCM group were higher than those in the control group (P < 0.05); left ventricular ejection fraction (LVEF), left ventricular fractional shortening (FS) rate, stroke volume (SV), cardiac output (CO), cardiac index (CI), A peak, and the e' and a' velocities of both the lateral wall and interventricular septum were smaller than those in the control group (P<0.05). The LS, CS, A, β, and A×β of the DCM group were all lower than those of the control group (P < 0.05). The pattern of myocardial strain and perfusion among myocardial layers was subendocardial>middle>subepicardial. The correlation coefficients of LS with A, β, and A×β were -0.500, -0.279 and -0.190, respectively, and the correlation coefficients of CS with A, β, and A×β were -0.383, -0.255 and -0.208, respectively.ConclusionsThe deformation of the three-layer myocardium and coronary microcirculation perfusion in DCM patients were diffusely damaged from the endocardium to the epicardium, layer by layer. The longitudinal function of the left ventricular myocardium was closely related to changes in myocardial microcirculation perfusion.