Congenital heart defect study

Heart catheterization is sometimes performed on children with congenital heart defects. A Teflon tube (catheter) 3 mm in diameter is passed into a major vein or artery at the femoral region and pushed up into the heart to obtain information about the heart’s physiology and functional ability. The length of the catheter is typically determined by a physician’s educated guess. In a small study involving 12 children, the exact catheter length required was determined by using a fluoroscope to check that the tip of the catheter had reached the pulmonary artery. The patients’ heights and weights were recorded. The objective was to see how accurately catheter length could be determined by these two variables (Weindling 1977). The data are given in the following table.