Estimation of right atrial pressure from the inspiratory collapse of the inferior vena cava in pediatric patients

ABSTRACT

Paucity of data exists between mean right atrial pressure [RAP] and inferior vena cava [IVC] size and collapsibility in pediatric patients with congenital heart disease. In a prospective study, fifty consecutive pediatric patients with different congenital heart diseases who had right side cardiac catheterization were studied, comparing right atrial pressure with simultaneous M-mode echocardiographic measurement of inferior vena cava diameter. Mean age of the patients was 4.96 +/- 4.05 years [30 male and 20 female]. Patients were categorized into two groups according to their right atrial pressure [RAP] as measured by cardiac catheterization Group 1 [40 patients] were those with mean RAP <8 mmHg and group 2 [10 patients] who had a mean RAP> 8 mmHg. In M-mode echocardiography IVC size was statistically different [P=0.004 and 0.009] in inspiration and expiration in the two groups. Mean RAP was estimated to be > 8 mmHg when IVC diameter in inspiration was >3.6 [sensitivity of 100%, specificity of 47.5%, +LR=1.9] or if IVC diameter was >6mm in expiration [sensitivity of 70%, specificity of 87%, +LR=4.67]. This study showed that measurement of IVC size in inspiration and expiration can be used as a reliable method for estimation of mean right atrial pressure