Objectives: To establish Z-score models for early diastolic blood flow widths of mitral and tricuspid valves in normal fetuses and compare Z-scores and other blood flow dynamic parameters between normal fetuses and fetuses with dilated coronary sinus (CS). This study seeks to assess whether dilated CS affects cardiac structure or hemodynamics.Methods: One hundred twenty-nine normal fetuses (Group I) and 15 fetuses with dilated CS connected to persistent left superior vena cava (PLSVC) (Group II) were included in this study. Noncardiac biometrical parameters, including gestation age (GA), biparietal diameter (BPD), femoral length (FL), and heart area (HA), were obtained. Hemodynamic parameters, such as the early diastolic blood flow widths of mitral and tricuspid valves (MV-CDFI-Width, TV-CDFI-Width), velocity and time integral of blood flow (VTI), peak early and late diastolic velocity of mitral and tricuspid valves [peak early diastolic velocity of the mitral valve (MVE), peak late diastolic velocity of the mitral valve (MVA), peak early diastolic velocity of the tricuspid valve (TVE), peak late diastolic velocity of the tricuspid valve (TVA)], were measured.Results: Z-score models for MV-CDFI-Width and TV-CDFI-Width against noncardiac biometrical parameters were best described by linear regression analysis. The mean equations of MV-CDFI-Width against noncardiac biometrical parameters were 0.066 + (0.025 × GA), 0.169 + (0.084 × BPD), 0.213 + (0.106 × FL) and 0.533 + (0.028 × HA). The SD for MV-CDFI-Width against FL was estimated based on values from the following equation: -0.006 + (0.02 × FL). Other SDs were constants estimated as the standard deviations of the unscaled residuals. Z-scores and other blood flow dynamic parameters exhibited no statistically significant differences between Group I and Group II.Conclusions: This study demonstrated that dilated CS did not affect fetal hemodynamics of the mitral or tricuspid valves or cardiac structures. We also suggested that the causes of diminutive left heart or coarctation of the aorta might not be associated with dilated CS in fetuses with PLSVC.
Keywords: Blood flow widths of mitral valve; Z-score; blood flow widths of tricuspid valve; dilated coronary sinus; persistent left superior vena cava.