Ductal shunting significantly affected the time necessary for aortic diastolic pressure to fall to one-halfan initially selected value (t1/2). Fourteen premature infants with clinical evidence of left-to-right ductal shunting had a mean t1/2 of 277 msec (range 133 to 383 msec) compared with a mean t1/2 of 455 msec (range 332 to 567 msec) in 14 neonates with no clinical evidence of ductal shungting (P<0.01). Seven older infants with ductal shunting confirmed at cardiac catheterization had a mean t1/2 of 360 msec (range 240 to 392 msec). Infant catheterization data and animal studies are suggestive of an inverse relationship between the magnitude of shunt and the t1/2. The t1/2 determined by diastolic pressure analysis is a useful method for serial evaluation of ductus arteriosus shunting.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health