Congenital heart disease laboratory findings

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor-In-Chief: Keri Shafer, M.D. [2], Atif Mohammad, M.D., Priyamvada Singh, MBBS; Kalsang Dolma, M.B.B.S.[3]

Laboratory Findings

Lab Studies in Congenital heart disease:^[1]

Erythrocytosis: Seen in cyanotic congenital heart disease
Hb > 20gm/dl: Seen in cyanotic congenital heart disease
Checking oxygen levels in the blood using an arterial blood gas test or by checking it through the skin with a pulse oximeter
Complete blood count (CBC)
Hyperoxia test: A hyperoxia test is a test that is performed–usually on an infant– to determine whether the patient’s cyanosis is due to lung disease or a problem with blood circulation.^[2]^[3] It is performed by measuring the arterial blood gases of the patient while he breathes room air, then re-measuring the blood gases after the patient has breathed 100% oxygen for 10 minutes.^[2]^[4] If the cause of the cyanosis is due to poor oxygen saturation by the lungs, allowing the patient to breath 100% O2 will augment the lungs’ ability to saturate the blood with oxygen, and the partial pressure of oxygen in the arterial blood will rise (usually above 150 mmHg^[4]). However, if the lungs are healthy and already fully saturating the blood that is delivered to them, then supplemental oxygen will have no effect, and the partial pressure of oxygen will usually remain below 100mmHg.^[4] In this case, the cyanosis is most likely due to blood that moves from the systemic veins to the systemic arteries via a right-to-left shunt without ever going through the lungs.^[2]

References

↑ Braunwald Zipes Libby. Heart disease: A textbook of cardiovascular medicine, 6th Edition chapter 43:W.B. Saunders ;.pp 1523
↑ ^2.0 ^2.1 ^2.2 Fyler, edited by John F. Keane, James E. Lock, Donald C. (2006). Nadas’ pediatric cardiology (2nd ed. ed.). Philadelphia [u.a.]: Saunders [u.a.] ISBN 978-1-4160-2390-6.
↑ “When Do Cyanotic Congenital Heart Diseases Present?”. Pediatric Education. 2006-01-23. Retrieved 2011-10-26.
↑ ^4.0 ^4.1 ^4.2 Dr. Ira Shah (2006-02-15). “How To Manage Blue Baby Maha Neocon 2005 pediatric oncall”. Pediatriconcall.com. Retrieved 2011-10-26.

Laboratory Findings