Exploring the association between magnetocardiographic parameters and echocardiographic indices of concentric left...

Left Ventricular Remodeling (LVR) in hypertension involves both structural and electrophysiological alterations. Magnetocardiography (MCG) non-invasively measures cardiac magnetic fields, potentially reflecting these changes. This study aimed to explore the association between MCG parameters and established Echocardiographic (ECHO) indices of concentric left ventricular remodeling in hypertensive patients.

In this cross-sectional study, 220 hypertensive patients underwent both ECHO and 9-channel MCG. Patients were categorized based on ECHO into Non-LVR (n = 105) and concentric remodeling groups (n = 115). Fifteen MCG parameters derived from the QRS complex and R-wave were analyzed. Correlations between MCG and ECHO parameters (Left Ventricular Mass Index [LVMI], Interventricular Septal thickness [IVSd], Left Ventricular Posterior Wall thickness [LVPWd], Relative Wall Thickness [RWT]) were assessed. A multivariate associative model combining selected MCG parameters was developed in a 70% subset (n = 154), and its association with ECHO-defined concentric structural phenotype was tested in a separate 30% validation subset (n = 66).

After rigorous correction for multiple testing, several MCG parameters demonstrated statistically significant correlations with specific ECHO indices. The maximum current moment of the QRS complex (QRS_MCM) showed positive correlations with IVSd (r = 0.388, p < 0.00083), LVPWd (r = 0.333, p < 0.00083), and RWT (r = 0.392, p < 0.00083). The relative timing parameters QRS_CA ratio and QRS_FMA ratio exhibited significant positive correlations with both IVSd and RWT (r = 0.299-0.339, all p < 0.00083). Patients in the ECHO-defined concentric remodeling group exhibited a distinct MCG profile characterized by increased current moments, altered current angles, and higher depolarization timing ratios compared to the Non-LVR group. The multivariate associative model, incorporating QRS_MCM, R_CA, QRS_CA ratio, and QRS_FMA ratio, showed a strong association with concentric structural phenotype in the development set (AUC = 0.887, 95% CI 0.832-0.942). Critically, this association remained robust and significant when the model was applied to the independent validation set (AUC = 0.856, 95% CI 0.763-0.948). The internal validation confirmed the stability of this associative pattern, though the model is not intended for clinical diagnostic use.

Specific magnetocardiographic parameters, particularly those reflecting the global strength of ventricular depolarization (QRS_MCM) and the relative timing of electrical events within the cardiac cycle, are significantly and robustly associated with echocardiographic indices of concentric left ventricular remodeling in hypertension. These cross-sectional findings establish a measurable link between MCG-based electrophysiological features and concentric structural alterations in hypertensive patients. Further prospective studies are needed to explore the temporal relationship between electrical and structural remodeling and to determine whether MCG offers insights beyond those obtainable from simpler, more widely available tools such as the ECG.