Wednesday, January 30, 2008

Blue Baby

A newborn presents with profound cyanosis, agitation, and increased respiratory rate. You listen to the heart and only hear a single second heart sound (no split) along with a faint crescendo-decrescendo murmur. Here is the CXR:

Challenge: What's the diagnosis?

Related Questions:
1. With a larger obstruction, do you get a louder or fainter murmur?
2. What's seen on the CXR?

Image is shown under fair use.

2 comments:

Craig said...

Blue Baby

Tetralogy of Fallot involves four anatomic features: pulmonary artery stenosis, intraventricular communication (ventricular septal defect), deviation of the origin of the aorta to the right, and concentric right ventricular hypertrophy. During development, there is anterior and cephalad deviation of the infundibular septum resulting in a VSD with the aortic root overriding the defect causing RV outflow obstruction. The clinical presentation depends on the degree of RV outflow obstruction. Here, the profound cyanosis in the immediate newborn period indicates severe obstruction and inadequate pulmonary flow. With a larger obstruction, the flow across the right ventricular outflow tract decreases (blood is shunted through the VSD), and the murmur becomes softer. The CXR shows a classic “boot-shaped” heart.

Sources: UpToDate; Baylor College of Medicine website (www.bcm.edu)

Alex said...

hey, went to a CXR talk today and found out something cool about the picture. The bright white band is the esophagus, stained with a barium swallow. Its displacement is used to figure out how the aorta is positioned - which I presume may stage the severity of the disease.