Left Atrial Volume and Phasic Function Assessed by 4D Auto LAQ Echocardiography in Treatment-Naive, Newly Diagnosed Type 2 Diabetes Mellitus Patients Without Hypertension or Obesity

(1) Background: Our aim was to evaluate left atrial (LA) volumes and function in patients with newly diagnosed, treatment-naive type 2 diabetes mellitus (T2DM) using Four-Dimensional Automated Left Atrial Quantificative (four-dimensional auto LAQ) analysis and to explore the independent factors influencing left atrial function in diabetic patients. (2) Method: A total of 62 treatment-naive, newly diagnosed T2DM patients without hypertension or obesity and 50 healthy controls were prospectively enrolled in the study. All participants underwent laboratory analyses, routine echocardiography and 4D LAQ assessment. The parameters were compared between the two groups, and independent factors influencing left atrial function in diabetic patients were investigated through univariate and multivariate linear regression analyses. (3) Results: Despite no significant difference in LA end-systolic anteroposterior diameter between groups, LA volume parameters (LAVmax, LAVmin, LAVpreA, and LAVmaxI) were significantly increased in T2DM patients (all p < 0.05). Regarding LA strain, reservoir and conduit function were significantly impaired in T2DM patients, as reflected by lower LASr, LAScd, LASr-c, and LAScd-c (all p < 0.05). Conversely, circumferential contractile strain (LASct-c) was significantly higher in the T2DM group (p = 0.029), while longitudinal contractile strain (LASct) did not differ significantly between groups (p = 0.146). Multivariate analysis revealed that HbA1c and E/e’ ratio were independently associated with multiple LA strain parameters (all p < 0.05). (4) Conclusion: Newly diagnosed, treatment-naive patients with T2DM exhibited increased LA volumes, decreased left atrial ejection fraction (LAEF), and impaired reservoir and conduit functions, accompanied by a compensatory increase in contractile function. Furthermore, HbA1c and E/e’ demonstrated an independent correlation with 4D strain parameters. 4D Auto LAQ echocardiography may serve as a sensitive tool for early detection of diabetic atrial myopathy.