This study aims to elucidate the correlation between endothelial function and both cardiac structure and function in patients newly diagnosed with primary (essential) grade 1 hypertension.We retrospectively reviewed clinical and echocardiographic data from 109 patients attending a cardiology outpatient clinic from January to December 2022. All subjects underwent comprehensive laboratory tests including lipid profile, glucose, electrolytes, and high-sensitivity C-reactive protein, alongside echocardiography to assess cardiac function. A subset of 34 patients underwent flow-mediated dilation (FMD) testing to evaluate endothelial function, and the results categorized them into normal (FMD ≥ 6%) and reduced (FMD < 6%) endothelial function groups.The study found no significant differences in baseline demographic or clinical parameters between groups. Age was negatively correlated with FMD values, indicating decreased endothelial function with advancing age. The normal endothelial function group demonstrated better diastolic and systolic parameters and lower right ventricular Tei indices compared to the reduced function group. Additionally, there was a significant negative correlation between the right ventricular Tei index and FMD values.Endothelial function is associated with right ventricular performance in patients with primary (essential) grade 1 systemic hypertension. Improved endothelial function is associated with better overall cardiac performance. Further studies with age-matched controls are necessary to confirm these findings and determine the independent effects of hypertension on cardiac function.Copyright 2025, Wang et al.