New clinical guidelines spearheaded by the American College of Cardiology ( ACC ) and the American Heart Association ( AHA ) offer new recommendations for the diagnosis and management of thoracic aortic disease ( TAD ).

An aortic aneurysm occurs when a portion of the aorta balloons out, increasing the diameter of the blood vessel by at least 50 percent at that spot. Although the wall of the aorta can become dangerously thin, patients with an aortic aneurysm often have no symptoms unless the aneurysm ruptures.

In the case of aortic dissection, a tear in the inner lining of the aorta allows blood to invade the middle layer, creating a false passageway through which blood can flow. This false passageway steals a portion of the blood supply from the rest of the body. Classical symptoms include the sudden onset of intense pain in the chest, back, shoulder or abdomen. However, patients often experience less definite symptoms, which makes diagnosis difficult.
In aortic rupture, all three layers of the aortic wall burst, resulting in massive bleeding inside the body.

Risk factors for thoracic aortic disease include poorly controlled high blood pressure, advancing age, male gender, atherosclerosis, inflammatory diseases that damage the blood vessels, and certain genetic conditions that weaken connective tissue, such as Marfan syndrome. In addition, people whose aortic valve has only two leaflets ( bicuspid valve ) instead of the normal three leaflets may be at increased risk for an aortic aneurysm. Pregnancy, intense weight lifting and cocaine use increase the risk of aortic dissection.

One of the most important messages in the guidelines is that thoracic aortic disease often runs in families. As a result, family history is a critical tool for uncovering undiagnosed cases of TAD. Patients should tell their physicians not only about close relatives with aortic aneurysm, dissection, or rupture, but also about any family history of unexplained sudden death.

Additional highlights from the TAD guidelines include:

Imaging of the thoracic aorta by computed tomography ( CT ), magnetic resonance imaging ( MRI ) or, in some cases, echocardiography is the best way to detect TAD and determine future risk. A chest x-ray alone is not sufficient;

Patients with genetic conditions that increase the risk of TAD should have aortic imaging at the time of diagnosis to establish the size of the aorta, with periodic follow-up imaging thereafter;

All patients with a bicuspid aortic valve should be evaluated to determine whether the aorta is dilating, or widening;

The symptoms of acute aortic dissection, which can mimic those of a heart attack or another cause of chest pain, often make it difficult to arrive at a prompt diagnosis and may delay life-saving treatment. Physicians should keep aortic dissection in mind when asking questions about medical history, family history, and the type and pattern of pain, and when examining the patient;

Aortic dissection involving the ascending aorta is a life-threatening emergency that should be treated surgically;

Aortic dissection involving the descending thoracic aorta may often be managed with medications that control the blood pressure and heart rate, unless life-threatening complications develop. Additional medical therapy may include statins to lower elevated blood cholesterol levels;

Minimally invasive endovascular techniques are an option in some patients with aneurysm or dissection of the descending thoracic aorta;

All immediate relatives of a patient with thoracic aortic aneurysm or dissection, or a bicuspid aortic valve, should be evaluated by a cardiovascular physician and undergo aortic imaging to measure the size of the aorta and identify asymptomatic disease.

Source: American College of Cardiology, 2010

XagenaMedicine2010


Link: Xapedia - Medical Encyclopedia