THORACIC DISEASES: TYPE A DISSECTION

An aortic dissection is a condition that causes sudden and severe pain in the chest, back or belly.  It involves the aorta, which is the main blood vessel that comes out of the heart and carries blood to the body.  An aortic dissection can happen anywhere in the aorta.  When it involves the first part of the aorta close to the heart, the ascending aorta, it is called a Type A Dissection.

In an aortic dissection, there is a tear in the inner wall and blood runs in between the layers that make up the wall of the aorta.  This predisposes the aorta to bursting.  Change in the pattern of flow due to the tear can result in any of the body’s organs not receiving enough blood flow.

Type A Dissections of the thoracic aorta are a medical emergency requiring immediate intervention.  Many people who have a Type A aortic dissection don’t survive, even with treatment.

What are the Symptoms?

Patients have described ripping chest pain from the center of the chest radiating to the back, between the shoulder blades, is a classic symptom of Type A dissections. Sometimes patients may describe mild pain in the chest, back or groin and it is easy to dismiss these cases as being musculoskeletal pain. Fainting can also be a common symptom and is associated with increased mortality.

How is it Diagnosed?

Diagnosis of acute Type A dissections is generally based on typical presentation, history and physical exam. The first problem is to distinguish aortic dissection from myocardial infarction. The diagnosis cannot always be made by history and physical signs alone. If suspicion is high for dissection, most commonly a CT Scan will be performed to confirm diagnosis and assess for surgical intervention. Each diagnostic test has varying pro’s and con’s and sometimes the imaging technique is based on presumed diagnosis, availability of testing equipment, patient stability and the sensitivity and specificity of the test. Each center may have a different protocol with regard to which tests to administer and in which order.