To systematically evaluate alterations in left atrial (LA) function in patients with essential hypertension (EH) using four-dimensional automatic left atrial quantification (4D Auto LAQ) technology, and to identify the optimal echocardiographic parameter for efficiently detecting left ventricular diastolic dysfunction (LVDD) in this population.

A cross-sectional study was conducted, consecutively enrolling 133 EH patients treated at the Second Affiliated Hospital of Air Force Medical University between October 2023 and November 2025, along with 50 healthy volunteers as the control group. EH patients were stratified into four subgroups (pre-hypertension, grade 1, grade 2, and grade 3) according to the 2024 revised Chinese Guidelines for the Prevention and Treatment of Hypertension. LVDD was diagnosed based on the updated 2025 American Society of Echocardiography guidelines for diastolic function assessment. All participants underwent comprehensive transthoracic echocardiography, including standard two-dimensional and three-dimensional full-volume image acquisition. Offline analysis was performed using an ECHOPAC 204 workstation with 4D Auto LAQ software to derive LA volumetric, longitudinal, and circumferential strain parameters. Calculated indices included LA emptying fraction (LAEF), passive and active ejection fractions (LAPEF, LAAEF), expansion index (LAEI), LA volume/mechanical coupling index (LAVMCI), LA-ventricular coupling index (LACI), and LA stiffness index (LASI). Inter-group comparisons were conducted using one-way analysis of variance followed by the LSD-t post hoc test. The diagnostic performance of each parameter for LVDD was evaluated using receiver operating characteristic (ROC) curve analysis.

Compared with the control group, the prehypertension group exhibited significantly increased LA minimum volume (LAVmin) [(18.57±4.76) ml vs (15.09±5.16) ml] and pre-systolic volume [(32.30±8.95) ml vs (26.00±8.61) ml], along with significantly decreased LAEF [(56.17±6.71)% vs (60.89±6.23)%], LAPEF [(0.25±0.09) vs (0.33±0.07)], and circumferential strain (LASr-c) [(31.70±7.62)% vs (37.91±11.42)%] (all P＜0.05). With increasing severity of hypertension, LAVmax increased from (38.29±11.28) ml to (70.92±19.17) ml, LAVmin from (15.09±5.16) ml to (37.08±10.10) ml, and LAVMCI from (2.60±0.94) to (5.09±1.93) (all P＜0.001); meanwhile, LASr decreased from (27.71±6.32)% to (16.67±4.81)%, and LAScd from (-15.23±4.81)% to (-6.33±3.17)% (all P＜0.001). In EH patients with LVDD, LAVMCI was significantly higher than that in the normal group [(6.56±3.31) vs (2.59±0.88), t=8.949, P＜0.001]. ROC curve analysis demonstrated that LAVMCI had the highest diagnostic efficacy for identifying LVDD in EH patients, with an area under the curve (AUC) of 0.951 (95% confidence interval: 0.92-0.98). At an optimal cutoff value of 2.75, the sensitivity and specificity were 100% and 69.15%, respectively, which was significantly superior to LASr (AUC=0.721).

4D Auto LAQ technology can sensitively detect impairment of LA reservoir, conduit, and contractile functions beginning at the prehypertension stage. Among the multiple parameters assessed in this study, LAVMCI demonstrated the optimal diagnostic performance for LVDD in EH patients, suggesting that it may serve as a potentially effective parameter for evaluating hypertension-related diastolic dysfunction.