Diagnosing Aortic Dissection

At NYU Langone, our team of doctors works together to diagnose an aortic dissection. The condition occurs when a tear in the aorta, the body’s largest artery, causes its inner layers to separate or its outer wall to rupture.

Aortic Dissection Symptoms

Aortic dissection symptoms differ based on whether the condition is acute or chronic.

People with an acute aortic dissection may experience shortness of breath, difficulty speaking, weakness on one side of the body, or a loss of vision. Some people faint, and some become sweaty. Symptoms usually begin suddenly and may include severe chest or back pain that may be felt as sharp or stabbing or as a tearing. Sometimes, the pain moves to the neck, jaw, shoulder, arm, or abdomen.

Acute aortic dissection can be life-threatening and requires immediate treatment. Most people are admitted to the hospital through the emergency department.

Symptoms of chronic aortic dissection persist beyond 14 days of the initial event, when the first signs of dissection may be noticed. These symptoms can include abdominal, back, or chest pain. There also may be no symptoms.

Aortic aneurysm, which is an enlargement or bulging of the aortic wall, can sometimes occur at the same time. It can also lead to an aortic dissection.

Aortic Dissection Risk Factors

Aortic dissection occurs most often in men between the ages of 40 and 70 years, but it can also occur in women and younger adults.

There are several common causes. Chronic, uncontrolled high blood pressure and hardening of the arteries, known as atherosclerosis, can weaken the tissues of the aorta, making it more likely to tear. Some people are born with hereditary conditions, such as aortic valve defects, in which the valve that controls the flow of blood to the aorta doesn’t work properly, or Marfan syndrome, which can lead to an enlarged and weakened aorta. Blunt, traumatic injury to the chest, such as hitting the steering wheel of a car during an accident, can also cause an aortic dissection. Chronic cocaine users and people who lift heavy weights can also stress the layers of the aortic wall, which can lead to a dissection.

Rarely, a pregnancy-related condition called preeclampsia, which is often signaled by hypertension, causes an aortic dissection, particularly in the third trimester or soon after delivery. Added stress on the arteries during pregnancy in women with connective tissue disorders, such as systemic lupus erythematosus, can lead to an aortic dissection.

Aortic Dissection Diagnostic Tests

Because most aortic dissections are acute—sudden and dangerous—they are typically diagnosed in the hospital.

Your doctor takes a medical history and checks for abnormal heart sounds, such as the swishing sound of a murmur, which can indicate a leaking aortic valve. He or she also notes whether the blood pressure in one arm is different from that in the other—a sign that the aortic dissection has interrupted flow to an arm. This may indicate that the arteries supplying blood to the chest and arms are blocked or closed off by an aortic dissection.

Your doctor may order one or more tests to help identify a tear in the aorta.

X-ray

Doctors may take an X-ray of the lungs, heart, and aorta. This can reveal a widening of the aorta, a sign of a dissection.

CT Scan

CT scans use X-rays to create cross-sectional computer images of the chest and the abdomen. Before the test, your doctor asks you to drink a contrast agent, which makes the heart, aorta, and other blood vessels more visible on the images. During the test, you lie on a narrow bed that moves you in and out of the CT machine. These scans can determine the location and size of an aortic dissection.

Transesophageal Echocardiogram

A transesophageal echocardiogram uses sound waves to create images of the heart. A doctor inserts an ultrasound probe through your mouth and into the esophagus. Because the probe is placed close to the aorta, the test provides clearer images of a dissection than a regular echocardiogram, which uses probes placed on the chest. A transesophageal echocardiogram can be performed at the bedside in the hospital. It takes just 15 minutes and requires a light sedative.

MRI Scan

An MRI scan helps your doctor determine the location and size of the aortic dissection. During this procedure, a magnetic field and computer are used to create clear, cross-sectional images of the aorta.

You are asked to lie inside a machine that contains a strong magnet, and images of your aorta are sent to a computer to be analyzed by a radiologist and your doctor. Some MRI machines are open, which may be better tolerated by people who feel claustrophobic during a conventional scan.

Magnetic Resonance Angiogram

A magnetic resonance angiogram, or MRA, is a type of MRI scan. The test uses contrast dye, which is given through a small catheter placed in the arm, to provide clear images of the blood flow in the aorta and blood vessels.

This scan can show if an aortic dissection has caused a new channel, called a false lumen, to form between the aortic layers. When pressure builds in the false lumen, the weakened portion of the aortic wall bulges. This is called an aneurysm, and it can eventually rupture if it continues to grow.

Because an MRA takes longer to prepare and administer than a CT scan, doctors generally reserve it for chronic aortic dissections, which do not usually require emergency treatment.