Echocardiographic evaluation of inferior vena cava diameters and collapsibility index in healthy children.

Introduction. Echocardiographic measurement of inferior vena cava diameters and collapsibility index (IVCCI) can estimate right heart chamber function and intravascular volume status. Few reports of reference values for diameters and IVCCI in the pediatric population exist. This exploratory study aimed to understand the behavior of diameters and IVCCI as a function of body surface area (BSA) in healthy children to establish possible reference values in the future. Population and methods. Ninety-nine Mexican children aged 12 to 204 months were included. Anthropometry and transthoracic M-mode echocardiography were performed to assess the maximum expiratory diameter (MAXDE) and the minimum inspiratory diameter (MINDI). IVCCI was calculated with the formula (MAXDE - MINDI) / MAXDE × 100. Results. A linear regression model was performed to calculate the predicted values (mean ± 2 standard deviations of MAXDE and MINDI expressed per BSA). The predicted value of the IVCCI for each representative BSA value was calculated from the MAXDE and MINDI values predicted by the model. Conclusions. Variations were found in the values of diameters and IVCCI concerning studies performed in other pediatric groups. This indicates the importance of having specific reference values for each population and opens the door to generating more research in healthy children and even those with cardiac disorders.