Spontaneous coronary artery dissection (SCAD) is a tear in one of the blood vessels that feeds the heart muscle. It is a less common cause of a heart attack.
SCAD is usually not caused by traditional risk factors of a heart attack. And women under 50 years of age are the most likely group to have SCAD.
SCAD symptoms are similar to those of a traditional heart attack and can include chest pain, dizziness, nausea, sweating, trouble breathing, and pain in the arm, neck, or back.
A heart attack (myocardial infarction) happens when there is not enough blood flow to the heart muscle. This occurs when there is a blockage in the coronary arteries, the blood vessels that supply oxygenated blood to the heart. Most commonly, this blockage is caused by atherosclerosis, or plaque in the artery wall.
In a spontaneous coronary artery dissection (SCAD), the blockage occurs because there is a tear in the artery, which leads to a buildup of blood in the blood vessel wall. And this can occur in people without typical risk factors.
In this article, we review what causes SCAD, who is at increased risk, the most common symptoms, and treatment.
SCAD is an increasingly recognized and studied condition, and experts now estimate it is responsible for 1 to 4% of all heart attacks. It is also the most common cause of heart attacks in younger women.
The exact cause of SCAD is not known, but it may be related to underlying problems with the blood vessels that make them more likely to tear. Because it is more common in women, especially in women who are pregnant or were recently pregnant, it could be related to hormonal changes. But no specific link between SCAD and hormonal changes has been identified. Researchers are still learning about the risk factors and medical problems that lead to SCAD.
Even though researchers are still trying to understand exactly what causes SCAD, they have identified some risk factors for the condition:
Female sex: Somewhere between 87% to 95% of people who have SCAD are female.
Pregnancy: SCAD is the most common cause of a heart attack in women who are pregnant or were recently pregnant. Women who have had multiple pregnancies have a higher risk of SCAD.
Conditions that affect the structure of blood vessels: There are a few inherited medical conditions that affect the structure and composition of the artery walls. These are sometimes referred to as connective tissues disorders, and examples include Marfan syndrome, Ehlers-Danlos syndrome, and Loeys-Dietz syndrome. Fibromuscular dysplasia is another example of a condition in which the blood vessel walls can have abnormalities that make them more likely to tear.
Autoimmune conditions: Some autoimmune diseases can cause inflammation of the blood vessels, or vasculitis. SCAD has been reported in some patients who have an underlying inflammatory disorder, though it is still uncommon.
Recreational drugs: Cocaine and methamphetamine use can increase someone’s risk of SCAD.
Hormones: Even though we are still learning about the connection, most clinicians recommend that people who have had SCAD avoid taking hormones. People typically take hormones for infertility treatment, contraception, or postmenopausal therapy.
Migraines: Many people who have SCAD also have a history of migraine headaches, but it is not clear how these conditions are linked.
There is currently no evidence to suggest that having a family member with SCAD increases your risk.
While the cause of SCAD is not entirely understood, it is likely the result of complex interactions between predisposing factors and emotional or physical triggers.
Over half of patients with SCAD report experiencing a trigger — either emotional or physical — before their event. Some people remember this as intense emotional stress. Others report a physical trigger, such as heavy weight lifting, intense aerobic exercise, or even severe vomiting, coughing, or a bowel movement.
But researchers are still trying to understand the association between physiologic stress and SCAD.
Similar to heart attacks from other causes, SCAD is associated with a variety of symptoms, which range in severity. The most common symptoms include:
Chest pain, pressure, or tightness
Shortness of breath
Nausea or vomiting
Feeling dizzy or light-headed
Pain in the arm, back, shoulder, or neck
There are other symptoms that people with SCAD experience, but these are less specific to the condition and can be caused by many different things:
Cold, clammy skin
Confusion or disorientation
The first thing that will help providers diagnose SCAD is having a good idea of a person’s symptoms. But there are also several tests that can help to diagnose SCAD:
Electrocardiogram (EKG): an electrical tracing of the heart beat
Lab tests: specifically, a test measuring troponin levels, which become elevated when the heart muscle is deprived of oxygen
Cardiac catheterization (cath): a procedure performed by a cardiologist, who uses a special dye to get a detailed view of the coronary arteries
CT (computed tomography) and MRI (magnetic imaging): radiology tests used to take a closer look inside the body
A cath is the most crucial test when it comes to a provider telling the difference between SCAD and other types of heart attacks. CT and MRI scans can provide images of the coronary arteries, but they are not as good as a cath for diagnosing SCAD.
When someone is diagnosed with SCAD, it usually requires a short stay in the hospital. During that time, the goal of treatment is to ease symptoms and prevent the artery tear from progressing further. This usually involves a combination of pain medication and medication that helps control blood pressure and heart rate. This allows the body to heal the damage to the blood vessel on its own.
In very rare cases, more involved treatment is needed. This could be a cath, which can also be used to repair the damaged blood vessel, or coronary bypass surgery, which involves replacing the vessel entirely. But these are less common and only done when absolutely necessary.
After someone has recovered from SCAD, long-term treatment aims to prevent it from happening again. This might include:
A cardiac rehabilitation program, which can help a person start exercising again, safely
Beta blockers, particularly in the case of high blood pressure, which can decrease the heart’s workload
If you have had SCAD, there are other things that you can do to prevent a recurrence:
Avoid emotional stress.
Get regular low- or moderate-intensity exercise.
Avoid high-intensity activity and exercise.
Start new exercise programs slowly.
Avoid recreational drugs.
If applicable, talk to your provider about the risk of SCAD with future pregnancies.
Be sure to take all your prescribed medications, particularly ones that keep your heart healthy, like blood pressure medications.
For most people, the affected coronary arteries heal on their own. In one study of patients with SCAD, over 80% were treated with medication alone and did not need any further intervention. In the same study, about 20% of patients with SCAD had another serious cardiac event.
The percentage of people who experience serious complications from SCAD could be overestimated since mild cases might be missed or misdiagnosed.
Like other forms of heart attacks, SCAD can cause significant damage to the heart muscle if it’s deprived of oxygen for too long. This can permanently affect heart function. In rare cases, SCAD can even be fatal.
If you have symptoms of a heart attack, you should seek care right away, even if you don’t think you have the usual risk factors or your symptoms don’t feel particularly severe. Like other forms of heart attacks, SCAD symptoms can range from mild to severe.
SCAD is a tear in a coronary artery that can cause a heart attack. And it is more common in younger women without the usual risks for heart disease. If you know you have an underlying condition that affects your arteries, talk to your provider about how to minimize your risk of complications like SCAD. If you have had SCAD, make sure to follow up with your cardiologist and take your medications, especially those that can help control your blood pressure. And most importantly, if you are experiencing heart attack symptoms — especially chest pain — you should seek emergency medical care.
Fibromuscular Dysplasia Society of America. (n.d.). FMD info.
Hayes, S. N., et al. (2018). Spontaneous coronary artery dissection: Current state of the science: A scientific statement from the American Heart Association. Circulation.
Hayes, S. N., et al. (2020). Spontaneous coronary artery dissection: JACC state-of-the-art review. Journal of the American College of Cardiology.
Kok, S. N., et al. (2018). Prevalence and clinical factors of migraine in patients with spontaneous coronary artery dissection. Journal of the American Heart Association.
Saw, J., et al. (2014). Spontaneous coronary artery dissection: Association with predisposing arteriopathies and precipitating stressors and cardiovascular outcomes. Circulation: Cardiovascular Interventions.
Saw, J., et al. (2017). Spontaneous coronary artery dissection: Clinical outcomes and risk of recurrence. Journal of the American College of Cardiology.
Tweet, M. S., et al. (2019). The evidence on estrogen, progesterone, and spontaneous coronary artery dissection. JAMA Cardiology.