- There are more adults with congenital heart disease in this world than you would expect! Roughly 1 million
- Transposition of the great vessels is now repaired with an arterial switch. Prior to the late 1980s it was repaired with an atrial switch which had many more complications
- Call a cardiologist early if you are evaluating an adult with congenital heart disease in the ED. There’s a ton of specialized knowledge here.
As an internist, why should I review this?
- Disease like TGA used to mean certain death in infancy, but effective surgical interventions have caused mortality to plummet. The mortality rate for TGA with surgical repair is now 5%
- As a result, ~1 million adults (!) were born with a congenital heart defect of some kind.
- about half of those are thought to have complex congenital heart disease.
- 2-3% have transposition
- So regardless of what you practice you will likely touch them in some way
Anatomy at birth
- Technically TGA is divided into d-TGA (common) and l-TGA (uncommon)
- l-TGA does not cause cyanosis, is vanishingly rarely, and will not be reviewed here
- The name says it all. In d-TGA the aorta is connected to the RV and RA, while the pulmonary artery is connected to the LA and LV (see below)
- This causes cyanosis because the L sided circulation is basically creates a closed circuit. Deoxygenated blood flows from the SVC/IVC into the right atrium, then the right ventricle, then out the aorta and back into the pulmonary circulation
- Co-occuring VSDs are common (there’s one in the picture below) and help support oxygenation prior to repair
- Since ~1988 uncomplicated d-TGA have been repaired with an Arterial Switch.
- How does it work? They cut the pulmonary artery and aorta and put them back where they belong.
- Long term complications
- This repair has relatively good outcomes because it returns basically normal cardiac and great vessel anatomy
- coronary ischemia – angina is clinically silent after this procedure because the heart is denervated
- dilation of the aortic root
- Prior to the late 1980s, most TGAs were repaired with an Atrial switch
- the words are so similar. The old one switches the atria. The new one switches the arteries =)
- How does it work?
- As above, a special channel (called a baffle) diverts de-oxygenated blood from the right atrium to the left atrium. the LV then pumps that blood into the pulmonary circulation.
- A second baffle connects the pulmonary vein to the right atrium, so that the right ventricle can pump it to the systemic circulation
- right heart failure and atrial arrhythmias, because the RV was not designed to act as an LV
- coronary stenosis in some specific subtypes of procedures
- problems with the baffle – leaks, occlusions, etc.
When i see an adult with congenital heart disease, what should I do?
- What is the original abnormality?
- Was it repaired? If so, how and when?
- What is the current anatomy? (understanding the path of blood flow is crucial.)
- Is there prosthetic material in place?
- Are there consequences of the congenital defect or repair? (I.e., pulmonary hypertension, R vs. L-sided heart failure, arrhythmias).
- Screening for “routine adult heart problems” (eg, atherosclerotic disease, acquired contributors to cardiomyopathy)
- Miscellaneous considerations: need for infective endocarditis ppx, anticoagulation, exercise restrictions, reproduction issues.
Brad also pointed out that the ACC/AHA has guidelines for managing adults with Congenital heart disease which can serve as a great resource.
Filed under: Morning Report