Electro-Mechanical Cardiac Remodeling in Metabolic Syndrome: Association Between Frontal QRS-T Angle and Subclinical Left Ventricular Dysfunction Assessed by Four-Dimensional Echocardiography

Background/Objectives: Metabolic syndrome (MS) has been demonstrated to be associated with subclinical myocardial dysfunction, which develops in the early stages. It has been hypothesised that traditional echocardiographic parameters may be insufficient in detecting these changes. The frontal QRS-T angle is an electrocardiographic parameter that is easily obtained and that reflects ventricular electrical heterogeneity. This study aimed to examine the relationship between the frontal QRS–T angle and left ventricular myocardial deformation, as assessed by four-dimensional strain echocardiography (4DSE), in patients with MS. Methods: The present cross-sectional study comprised 70 patients diagnosed with MS and 61 healthy individuals matched for age and gender. All participants underwent standard transthoracic and 4DSE examination and 12-lead electrocardiography. The values of global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS) and global area strain (GAS) were analysed. The frontal QRS-T angle was calculated as the absolute difference between the QRS and T axes. The interrelationships between the variables were assessed using correlation and multivariate linear regression analyses. Results: Despite comparable left ventricular ejection fraction (LVEF) between the groups, 4DSE-derived myocardial deformation parameters, including GLS, GCS, GAS, and GRS, were significantly impaired in the MS group. The frontal QRS-T angle was found to be significantly higher in patients diagnosed with MS in comparison to the control group (p < 0.001). A significant correlation was identified between the frontal QRS-T angle and GLS (r = 0.498, p < 0.001). In multivariable linear regression analysis, the frontal QRS–T angle was independently associated with GLS (standardized β = 0.501, p < 0.001). In exploratory receiver operating characteristic (ROC) analysis, the frontal QRS–T angle showed moderate discriminatory ability for GLS-defined impaired myocardial deformation area under the curve (AUC) = 0.720). Conclusions: An increased frontal QRS–T angle in individuals with metabolic syndrome was independently associated with subclinical LV dysfunction despite preserved ejection fraction (EF). These findings suggest that the frontal QRS–T angle may serve as a simple and readily available electrocardiographic marker associated with impaired myocardial deformation, warranting further validation in larger prospective studies.