Biventricular Coupling: Physiological Function, Anatomical Remodeling and Advances in Ultrasound Imaging.

The cardiovascular system is among the earliest functional systems in fetal development, playing a central role in maintaining circulation and ensuring oxygen and nutrient delivery. The fetal heart undergoes continuous maturation in anatomical configuration, hemodynamics, and biventricular coupling throughout gestation. Recent advances in ultrasound imaging-including Doppler, tissue doppler imaging (TDI), and two- and three-dimensional speckle tracking-have enabled comprehensive assessment of fetal cardiac structure and function. In addition, emerging techniques such as fetal heart quantification and multimodal imaging, along with artificial intelligence-based approaches, may offer new perspectives for evaluating ventricular coupling. This review indicates that pathological changes such as congenital heart disease (CHD) and premature closure of the ductus arteriosus can lead to fetal cardiac structural abnormalities and hemodynamic disturbances. Based on the core mechanism of biventricular decoupling in adults, these changes form the pathophysiological basis for impaired fetal biventricular coupling. Accordingly, further exploration is warranted for the evaluation of fetal biventricular coupling status. Subsequent studies should first establish its normal reference criteria and clarify the correlation between this indicator and perinatal outcomes.