Clinical utility of the ventricular septal defect diameter to aorta root diameter ratio to predict early childhood developmental defects or lung infections in patients with perimembranous ventricular septal defect.

Background: Ventricular septal defect (VSD) is the most frequent type of congenital heart disease. Conventional methods to evaluate VSD size and severity are both invasive and cumbersome to perform. We investigated whether the ratio between the diameter of the defect and the aortic root diameter (DVSD/DAR) would accurately reflect the degree of shunted blood and the severity of VSD in children with perimembranous VSD.

Methods: We recruited 987 children with perimembranous VSD (pmVSD) and used color Doppler echocardiography to calculate DVSD/DAR. 987 healthy children were recruited as control group. The pmVSD group was further stratified into four groups according to age (1 to 4 y) and again into four groups according to the DVSD/DAR ratio: children whose DVSD/DAR was 1/5 to <1/4, 1/4 to <1/3, 1/3 to 1/5, or 1/2 to <2/3 were assigned to groups A, B, C, and D, respectively. Height, weight, infection scores and systemic-pulmonary circulation ratio (QP/QS ratio) were compared among groups A, B, C and D. Then the relationship between the DVSD/DAR ratio and height, weight, QP/QS ratio, infection score were analysed by linear regression analysis.

Results: Compared to age-matched children without VSD (the controls), the mean height and weight of children in the pmVSD group were lower, and heights and weights were negatively correlated with the DVSD/DAR ratio. This ratio was significantly reduced in groups C and D compared to control group (both P<0.05). Infection scores of groups A and B were significantly higher only in the one-year-old subgroup, but were significantly higher in groups C and D for all ages compared to the control group (both P<0.05). QP/QS ratio of group C and D were higher than group A and group B (all P<0.05). Moreover, QP/QS ratio of group D for all ages were more than 2. In addition, linear regression analysis revealed that the DVSD/DAR ratio negatively correlated with height and weight and positively correlated with the QP/QS ratio and infection score.

Conclusions: Our results suggest that the DVSD/DAR ratio accurately reflects the growth and pulmonary infection rates in children with pmVSD. This ratio, therefore, may be a useful additional reference index to predict the consequences of pmVSD.