Wednesday, April 1, 2020

Undiagnosed Congenital Heart Disease
AMFS Pediatric Cardiologist

Of all newborns who present for an autopsy without an explanation for their cause of death, nearly 40% will be found to have had congenital heart disease (CHD) which was not diagnosed while they were alive.  (1)  This is because diagnosing children with congenital heart disease before they leave the nursery is a challenging problem which has been reduced but not eliminated by technology.  One study demonstrated that for every 700,000 live births, there will be 4,500 infants with CHD, 25% of these children will leave the hospital without a diagnosis, and roughly 30 infants will die from CHD before any cardiac diagnosis is made.  (2)  My review of the surgical database in central Florida is much better, only about 10% of children with CHD leave the hospital without a diagnosis and we have had very few deaths from undiagnosed CHD.

Two major forms of technology have been used as a means of addressing this problem.  The first is fetal cardiac ultrasound.  A nationwide program of fetal echocardiography in the Czech Republic was able to reduce the undiagnosed incidence of some very serious forms of CHD (Hypoplastic Left Heart) to less than 5%, but some serious forms of CHD (Transposition of the Great Arteries) remained at about 75% undiagnosed. (3)  In the United States, most fetuses receive an obstetric ultrasound but only those with an indication are referred for a cardiac evaluation.  (4)

The second form of technology is pulse oximetry.  Pulse oximetry can detect low oxygen saturations, which we would expect to find in “blue babies” at the time of discharge.  However, not all forms of serious CHD result in “blue babies”, and the results of pulse oximetry to find even “blue “ forms of CHD are mixed.  One study brought the incidence of undiagnosed congenital heart disease from 25% without routine pulse oximetry at the time of discharge to 4.4% (5), however other studies have shown mixed results with about half the children who should have been detected being missed (6-7).

Medical-Legal Considerations

As a result, children with CHD will continue to be discharged from the nursery without a diagnosis, and some will do quite poorly as a result.  Whether their medical course constitutes malpractice depends on how they were followed both as fetuses and as newborns, what tests they received, and what the parents understood the tests results would mean.  Certainly, physicians should emphasize that neither a fetal echocardiogram nor a pulse oximeter test at the time of discharge removes the possibility of CHD.

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1 Weber, MA, Ashworth, MT, Risdon, RA, et.al., “Sudden unexpected neonatal death in the first week of life: autopsy findings from a specialist centre.”  J Matern Fetal Neonatal Med., 2009 May;22(5):398-404.

2 Wren, C., Reinhardt Z, Khawaja, K, “Twenty year trends in diagnosis of life-threatening neonatal cardiovascular malformations.”  Arch Dis Child Fetal Neonatal Ed., 2008 Jan 93(1):F33-5.

3Marek J, Tomek V, Skovránek J, Povysilová V, Samánek M., Prenatal ultrasound screening of congenital heart disease in an unselected national population: a 21-year experience., Heart. 2011 Jan;97(2):124-30.

4Park, MK, Pediatric Cardiology for Practitioners, Mosby, 2008, 97.

5Riede FT, Wörner C, Dähnert I, Möckel A, Kostelka M, Schneider P., “Effectiveness of neonatal pulse oximetry screening for detection of critical congenital heart disease in daily clinical routine-results from a prospective multicenter study.” Eur J Pediatr. 2010 Aug;169(8):975-81. Epub 2010 Mar 1.

6BALU VAIDYANATHAN, GAYATHRI SATHISH, SINIMOL THOPPIL, et. al., Clinical Screening for Congenital Heart Disease at Birth:  A Prospective Study in a Community Hospital in Kerala, Indian Pediatrics, August 2010, 1-5.

Reich JD, Miller S, Brogdon B, Casatelli J, Gompf TC, Huhta JC, Sullivan K, “The use of pulse oximetry to detect congenital heart disease”, J Pediatr