Spontaneous coronary artery dissection (SCAD) is a tear in the wall of the coronary arteries that supply the heart with blood. SCAD is an important cause of heart attack in young women and can lead to sudden death, arrhythmias, and heart failure. Treating SCAD is different from heart attack treatment caused by cholesterol plaques or atherosclerosis.
Read on to understand the risk factors, symptoms, complications, and treatment of SCAD.
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SCAD: The Facts
A dissection is a tear in the inner lining of an artery. Blood can enter the tear and form a clot between layers of the arterial wall. Dissection can happen in arteries throughout the body, such as the aorta, the carotid artery, the cerebral artery, and the coronary arteries. This can ultimately obstruct blood flow to organs, which can lead to serious consequences.
The coronary arteries are the arteries that bring oxygenated blood to the heart. When dissection involves a coronary artery, as in SCAD, the heart muscle is deprived of oxygen and nutrients. As a result, the muscle tissue begins to die or infarct, meaning a heart attack occurs.
Heart attacks caused by SCAD are distinct from those caused by atherosclerosis (a buildup of cholesterol plaques in the arteries). SCAD is much less common, and in many cases affects people who don't have the typical risk factors for cardiovascular disease. Although the incidence of SCAD is likely underestimated, it is believed to be responsible for under 5% of heart attacks.
Non-Spontaneous Coronary Artery Dissection
Coronary artery dissection can also occur as a complication of a procedure, from trauma, or from atherosclerosis. In these cases, the dissection is not spontaneous, so by definition, they are not considered to be SCAD.
Symptoms of SCAD
Spontaneous coronary artery dissection symptoms can include the following:
- Sudden chest discomfort, particularly after strenuous physical activity or emotional distress
- Pain in the shoulders, arms, or jaw
- Shortness of breath
- Nausea and vomiting
- Light-headedness
- Extreme fatigue
- Palpitations
- Loss of consciousness
Warning Signs
Seek immediate medical attention if you develop concerning symptoms, such as chest discomfort and shortness of breath. These are signs of a heart attack, which requires emergency treatment.
Causes and Risk Factors
The causes of SCAD have not been fully determined, but there are several characteristics that are commonly found in SCAD. A combination of genetics, underlying arterial disorders, inflammation, hormones, and precipitating triggers appear to be responsible.
The following have been associated with SCAD:
- Fibromuscular dysplasia (FMD): Fibromuscular dysplasia is diagnosed in up to nearly two in three people with SCAD. FMD is a condition characterized by abnormal artery walls that may be narrowed and can be prone to aneurysm (an outpouching of the artery which can cause rupture) and dissection.
- Female sex: Up to nine in 10 cases of SCAD occur in women. SCAD is responsible for up to one-third of heart attacks in women under the age of 50 years.
- Inflammatory disorders: These include lupus, rheumatoid arthritis, and inflammatory bowel disease (including Crohn's disease and ulcerative colitis).
- Exogenous hormone use: These include oral contraceptive pills, hormone replacement therapy, testosterone therapy, and corticosteroids.
- Connective tissue disorders: These include Marfan syndrome, Loeys-Dietz syndrome, and vascular type Ehlers-Danlos.
- Polycystic kidney disease: This is an inherited disorder in which cysts form in the kidneys.
- Pregnancy or recent pregnancy
- Migraines
In addition to these risk factors, SCAD is also often associated with intense physical or emotional stress. People with SCAD often have had incidents or events leading up to their symptoms, including strenuous exercise, weight-lifting, vomiting, labor and delivery, or even a straining for a bowel movement.
Potential Complications
As previously discussed, SCAD causes heart attack. As with other forms of heart attack, when blood flow to the heart is restricted, other complications can occur.
When the heart is starved of oxygen, serious arrhythmias (problems with the rate or rhythm of heartbeats) like ventricular tachycardia and ventricular fibrillation can occur. Loss of consciousness and sudden cardiac death may result.
Additionally, during a heart attack from any cause, including SCAD, heart muscle begins to die from lack of oxygen. When enough muscle dies and becomes scarred, the heart will not pump as efficiently, which can lead to heart failure.
Diagnosis
SCAD is differentiated from other types of heart attack on coronary angiography (also known as cardiac catheterization). In this procedure, a cardiologist accesses the coronary arteries with a catheter and visualizes them with X-ray radiation.
Sometimes, more specialized intracoronary imaging is needed during the procedure for a more definitive diagnosis.
Treatment
Once SCAD is diagnosed, treatment depends on the location and extent of the dissection, as well as symptoms.
Revascularization
When SCAD involves a portion of a coronary artery that supplies a large part of the heart, or when SCAD is causing complications, either placement of a coronary stent or surgery may be necessary. This is known as revascularization.
How Is Revascularization Performed?
A cardiologist can access the coronary arteries through the blood vessels to open the blockage with a stent. Alternatively, a heart surgeon can bypass the blocked artery in a surgery called coronary artery bypass graft (CABG) surgery. Each of these procedures carries the risk of complications like bleeding and injury to the heart and blood vessels.
On the other hand, if the involved artery is small, symptoms are controlled, and there are otherwise no complications, a more conservative approach of watching and waiting is generally preferred. This requires observation in the hospital for a few days (since emergency intervention may become necessary early after diagnosis). In many cases, the dissection heals itself over time, and a watch-and-wait approach allows that to happen without imposing the risk of procedures.
Stents vs. Bypass Surgery for Treating Coronary Artery Disease
Medical Therapy
Medications used in the treatment of SCAD include:
- Antiplatelets like aspirin and/or clopidogrel (Plavix)
- Beta-blockers, particularly if arrhythmias or heart muscle weakness (cardiomyopathy) is present
- Angiotensin converting enzyme (ACE) inhibitors, particularly if high blood pressure or cardiomyopathy (a condition that makes it harder for the heart to pump blood to the rest of the body) is present
- Statin therapy
- Nitrates and/or calcium channel blockers for management of continued chest pain
How Heart Disease Is Treated
Follow-Up Care
Close follow-up with a cardiologist is essential after a diagnosis of SCAD. A cardiologist will prescribe any necessary heart medications, order any recommended cardiac studies, and answer questions about your condition.
Your cardiologist will also look for underlying causes of SCAD. Screening for FMD with imaging of the arteries elsewhere in the body is often done with computed tomography (CT) scans or magnetic resonance imaging (MRI). Genetic testing is recommended when there is suspicion of an inherited vascular disorder.
Cardiac rehabilitation is a structured program that includes education, monitored exercise, and support from a healthcare team over a period of weeks to months. Talk with your cardiologist before resuming previous exercise levels.
SCAD and Pregnancy
Women who have had SCAD should discuss the risks of hormonal contraception and pregnancy with their cardiologist and obstetrician, since these have been associated with SCAD.
Prevention
SCAD is unpredictable and is not associated with the typical risk factors for cardiovascular disease, like high cholesterol. Thus, it is not preventable in the way that heart attacks from cholesterol plaques can be prevented by controlling risk factors.
However, preventing complications after SCAD is important. Following up with a cardiologist and taking prescribed medications is the best way to prevent complications.
In those who have developed heart muscle weakness, medications like beta-blockers and ACE-inhibitors play a role in improving survival. If a stent was placed, antiplatelet medications like aspirin are essential to help keep the stent open. Treating any high blood pressure is also important.
Lastly, studies have shown that up to one in three people with SCAD go on to experience another episode of SCAD in the following decade, so it's important to pay attention to symptoms and report any changes or concerns to your cardiologist.
When to Seek Emergency Care
While SCAD can't necessarily be prevented, some of its complications can be prevented by seeking immediate treatment. If you experience concerning symptoms, such as sudden chest discomfort or shortness of breath, which may or may not be accompanied by nausea, light-headedness, or palpitations, seek medical attention immediately.
Summary
Spontaneous coronary artery dissection (SCAD) is a potentially life-threatening condition that causes heart attack. It can lead to arrhythmias, sudden cardiac death, and heart failure. It is more common in young women and has been associated with pregnancy, hormone use, inflammatory conditions, and certain vascular disorders.
Treating SCAD includes medications, possible revascularization, and close follow-up with a cardiologist for counseling on exercise, pregnancy, and hormone use.
A Word From Verywell
Symptoms of a heart attack should always be taken seriously, even if you are young and otherwise healthy. SCAD is known to disproportionately affect women, particularly young women, so it's important to be aware of the signs and symptoms.
Those who have experienced SCAD can be significantly impacted by psychological stress, anxiety about returning to normal activities, and concern about their health. In addition to the advice from your healthcare provider, online resources and support are available.
Frequently Asked Questions
Does spontaneous coronary artery dissection affect life expectancy?
SCAD is less commonly diagnosed than other causes of heart attack and is also underdiagnosed, so it is difficult to say with certainty how life expectancy is affected. Those who survive hospitalization for SCAD generally do well but have higher rates of heart attacks, mostly related to recurring episodes of SCAD.
What is the difference between a heart attack and SCAD?
SCAD is one cause of heart attack. Most heart attacks are caused by atherosclerosis (cholesterol buildup in the coronary arteries). SCAD, on the other hand, is an uncommon cause of heart attack, responsible for less than 5% of all heart attacks.
Learn MoreHeart Attack Overview
Is SCAD hereditary?
Research to identify genes that cause SCAD is ongoing. To date, there is no single gene that has been identified to cause SCAD. Studies performed on family members affected by SCAD have identified several different genetic mutations. Additionally, some inherited conditions, like Marfan syndrome and vascular Ehlers-Danlos, are considered risk factors for SCAD.
How long is recovery after SCAD?
Recovery is highly variable after SCAD. When SCAD is diagnosed, monitoring in the hospital is required for several days. Depending on whether complications develop or surgery is required, recovery can take days or weeks. Cardiac rehab is a structured program involving supervised exercise and counseling that can promote recovery and improve quality of life in SCAD.
