- What is the complication shown in this gross photograph in image 5.1 of the left heart opened to reveal the aortic valve?
There is a large transverse tear in the intima of the ascending aorta just above the aortic valve. This is an aortic dissection.
- What is demonstrated by this cross section of the aorta in image 5.2?
The blood from an aortic dissection has collected outside the aorta. Such dissections can lead to death in a number of ways: the patient may die from exsanguination; the blood may dissect up and around the great vessels and cut off carotid flow; the blood may dissect around coronary orifices and cut off blood flow to the heart.
- What histologic lesion is demonstrated in the media of the aorta with this mucin stain in image 5.3?
There is irregular disruption of elastic fibers consistent with cystic medial necrosis.
- What complication is shown here involving the mitral valve in image 5.4?
A valve leaflet appears "hooded" and is ballooned upward, consistent with prolapse of a floppy mitral valve.
- What is her underlying disorder?
This is Marfan syndrome, an autosomal dominant condition, as seen in image 5.5, in which there is a biochemical abnormality in the fibrillin gene with abnormal production of a protein, leading to abnormal elastin that weakens connective tissues with an elastic tissue component. The cardiovascular complications are life-threatening. This genetic syndrome exhibits pleiotropy--the genetic defect has manifestations in multiple organs. Many different fibrillin mutations exist, leading to variability in expression with mild to severe forms of the disease.
- What other risk factors may lead to the complication seen in images 5.1 and 5.2?
Atherosclerosis and hypertension are risk factors in most cases of aortic dissection.
- Pulmonary hypertension is often found in this disorder. What effect would this have on auscultatory findings?
Pulmonary hypertension would increase the time necessary to empty the right ventricle. Therefore, there would be a constant lag between the close of the aortic and pulmonic valves. Hence a constant splitting of S2.
- What are the issues regarding surgical intervention. When is surgery done, and by whom?
Informed consent requires explaining to the patient all the options for treatment, as well as outcomes, including potential complications. In the case of cardiovascular disease with Marfan syndrome, there is a substantial risk for aortic dissection, but the risk rises as the aorta dilates. The risk for mitral prolapse is not as great. When the aorta dilates above 3 cm in diameter, it is appropriate to consider replacement the aortic root and valve, generally by the 4th decade. However, there is a risk with surgery, too. Are surgeons more likely to recommend surgery earlier in the course, and cardiologists later?
An "evidence-based" approach considers information such as the following:
- Gott VL, Greene PS, Alejo DE, Cameron DE, Naftel DC, Miller DC, Gillinov AM,
Laschinger JC, Pyeritz RE. Replacement of the aortic root in patients with Marfan's syndrome. N Engl J Med. 1999;340:1307-1313.
- 675 patients with Marfan syndrome underwent aortic root replacement at 10 experienced surgical centers. The mean age was 34 years. The 30-day mortality rate was 1.5% in 455 patients undergoing elective repair, 2.6% in 117 undergoing urgent repair (within 7 days after a surgical consultation), and 11.7% in 103 patients who underwent emergency repair (within 24 hours after a surgical consultation). In adult patients who developed aortic dissection, 46% of 158 had an aortic diameter of 6.5 cm or less. No dissections occurred when the aorta was <3 cm in diameter. There were 114 late deaths (more than 30 days after surgery).
Who performs the surgery? Is this a decision made by the patient, the patient's primary care physician, or the health care provider organization? Outomes do vary by surgeon and by hospital. Is this information provided to the patient? The health care provider organization may have a contract with someone who has less skill and worse outcomes than someone a cardiologist might recommend. Should the cardiologist support the patient or the provider? Can you appeal the decision?
