Coronary artery dissection is a serious heart condition where a tear develops inside the wall of an artery that supplies blood to the heart, potentially causing a heart attack without warning. This condition particularly affects younger individuals, especially women, who often have no traditional heart disease risk factors.
Understanding Coronary Artery Dissection
Coronary artery dissection, often called spontaneous coronary artery dissection or SCAD, happens when a separation or tear forms in the wall of one of the heart’s arteries. These arteries, known as coronary arteries, carry oxygen-rich blood to your heart muscle. The wall of each coronary artery is made up of three thin layers of tissue. When a tear occurs, blood can seep between these layers and become trapped. This trapped blood causes the artery to bulge inward, which then blocks or slows down the flow of blood to your heart.[3]
The word “spontaneous” in this condition’s name means it happens without warning and without an obvious cause like trauma, a medical procedure, or the rupture of fatty deposits that typically cause heart attacks in older adults. Instead of being caused by atherosclerosis (the buildup of fatty deposits in arteries), SCAD occurs when the artery wall itself develops a problem. The tear can either start with a break in the inner lining of the artery, or it can begin with bleeding from tiny blood vessels within the artery wall itself, creating a bruise-like collection of blood called an intramural hematoma.[4]
This condition is particularly dangerous because the reduced blood flow can lead to a heart attack, a type of severe chest pain called unstable angina, dangerous heart rhythm problems, or in rare cases, sudden death. Because SCAD can be life-threatening, recognizing the symptoms and seeking immediate medical attention is critical.[1]
How Common Is This Condition?
Coronary artery dissection was once thought to be an extremely rare condition, but medical experts now recognize that it occurs more frequently than previously believed. It is considered underdiagnosed, meaning many cases may be missed or mistaken for other types of heart problems. Current estimates suggest that SCAD may account for up to 4% of all cases of acute coronary syndrome, which is an umbrella term for conditions causing sudden reduced blood flow to the heart.[3]
The condition shows a striking pattern in who it affects. SCAD is responsible for approximately one in four heart attacks among women younger than 50 years old. This makes it an especially important cause of heart attacks in younger female patients. Studies have found that it represents between 0.1% and 0.4% of all acute coronary syndrome cases in the general population, but when looking specifically at young women, the numbers are much higher.[9][12]
The condition predominantly affects women, with some studies showing that around 90% of SCAD patients are female. The average age at which SCAD occurs is about 50 years, though it has been reported in people ranging from 18 to 84 years old. Men account for less than 10% of SCAD incidents, making this condition notably more common in women than in men.[3][7]
What Causes Coronary Artery Dissection?
The exact cause of spontaneous coronary artery dissection remains unclear, and researchers continue to study why this condition develops. What makes SCAD particularly puzzling is that it often affects people who appear healthy and have none of the typical risk factors associated with heart disease, such as high cholesterol, high blood pressure, diabetes, or smoking. Many people who experience SCAD are younger, physically active, and have no known history of heart problems.[3]
One of the leading theories about what triggers SCAD involves the structure of the artery wall itself. Scientists believe the process may begin in one of two ways. First, there could be an intimal tear, which is a break in the innermost lining of the artery. Second, bleeding might occur from the vasa vasorum, which are tiny blood vessels that supply the artery wall itself. When these small vessels bleed, they create a bruise or collection of blood within the artery wall. This blood accumulation then puts pressure on the artery, causing the layers to separate and creating a false channel alongside the true blood flow pathway.[4][12]
The mechanism differs significantly from typical heart attacks caused by atherosclerosis. In atherosclerotic heart disease, fatty deposits build up in the arteries and eventually rupture, causing a blood clot. In SCAD, the arteries often appear smooth and free of disease in areas not affected by the dissection, suggesting the problem lies in the vessel wall’s structural integrity rather than cholesterol buildup.[4]
Research suggests that SCAD may have multiple contributing factors working together. These could include genetic predisposition, hormonal influences, environmental triggers, emotional stress, or underlying problems with blood vessel structure. While no single cause has been identified, the combination of these factors may create conditions where the artery wall becomes vulnerable to tearing or bleeding.[7]
Risk Factors for SCAD
Several factors have been identified that may increase a person’s likelihood of experiencing coronary artery dissection. Understanding these risk factors helps doctors identify individuals who might be at higher risk, though many people who develop SCAD have few or none of these risk factors.
Pregnancy and the postpartum period represent significant risk factors for SCAD. Studies show that around 10% of SCAD patients have their event around the time of pregnancy. More strikingly, SCAD accounts for 21% to 27% of all heart attacks during pregnancy and approximately 50% of heart attacks that occur in the postpartum period, particularly in the weeks immediately after delivery. This strong association suggests that hormonal changes during pregnancy and after childbirth may play a role in weakening artery walls.[7][9]
Hormonal fluctuations more broadly appear to be connected to SCAD risk. The condition is more likely to occur around the time of menstruation and during postmenopause. These timing patterns further support the idea that female hormones may influence artery wall stability. This connection also helps explain why SCAD affects women far more commonly than men.[3]
Certain medical conditions increase the risk of coronary artery dissection. Fibromuscular dysplasia (FMD), a condition that causes abnormal cell growth in artery walls, is found in many SCAD patients. Other conditions that affect connective tissue, such as Marfan syndrome, also increase risk because they can weaken blood vessel walls. Inflammatory diseases including lupus, multiple sclerosis, and sarcoidosis have been associated with higher SCAD risk as well.[3][6]
Dangerously high blood pressure, particularly if it rises suddenly, can stress artery walls and potentially trigger a dissection. Hypothyroidism, an underactive thyroid condition, and substance use disorders have also been linked to increased SCAD risk. Recent genetic research has identified certain genetic variants that may confer higher risk of experiencing SCAD, though it is not caused by a single gene in the way some hereditary diseases are.[3][7]
Physical and emotional stress can act as triggers for SCAD in susceptible individuals. Extreme physical exertion has been associated with SCAD symptoms in about 32% of patients. In men specifically, arterial tears most often occur after strength training or lifting heavy objects, suggesting that sudden physical strain may cause the tear. Similarly, severe emotional stress has been identified as a potential trigger. In rare instances, the physical force of severe vomiting or coughing may be enough to cause an artery wall to tear.[3][6][20]
Symptoms of Coronary Artery Dissection
The symptoms of coronary artery dissection are the same as those of a heart attack caused by other reasons. When the dissection blocks or slows blood flow to the heart muscle, it causes chest discomfort and other warning signs that require immediate emergency attention. The most common symptom is chest pain or pressure. This discomfort might feel like heaviness, fullness, tightness, or squeezing in the chest. The sensation can be mild or severe and may come and go.[1]
Pain or discomfort often spreads beyond the chest to other areas of the upper body. This can include one or both arms, the back, neck, jaw, or stomach. Some people describe the pain as radiating outward from the chest, while others feel discomfort in these areas without much chest pain at all. This pattern of pain distribution is characteristic of heart-related problems and should always be taken seriously.[1][6]
Shortness of breath is another common symptom of SCAD. This might occur with or without chest discomfort. People may feel like they cannot get enough air or that breathing requires more effort than normal. This happens because the heart muscle is not receiving adequate blood supply and cannot pump efficiently, leading to backup of fluid or reduced oxygen delivery to the body.[1]
Additional symptoms include unusual or excessive sweating, which may be described as “breaking out in a cold sweat.” People experiencing SCAD may feel clammy or notice that they are sweating profusely despite not engaging in physical activity or being in a warm environment. Nausea or vomiting can also occur, and some people experience upset stomach or indigestion-like symptoms. Extreme, unusual tiredness or fatigue that comes on suddenly is another warning sign.[1][3]
Heart rhythm disturbances may cause a rapid heartbeat or a fluttery feeling in the chest, known as palpitations. Dizziness, lightheadedness, or feeling faint can occur because the heart is not pumping blood effectively to the brain and body. In severe cases, people may actually faint or lose consciousness. These symptoms indicate that the heart is under serious stress and that emergency medical care is needed immediately.[1][3]
Can Coronary Artery Dissection Be Prevented?
Because coronary artery dissection occurs spontaneously and its exact cause remains unknown, there are no proven methods to completely prevent SCAD. However, certain lifestyle modifications and medical management strategies may help reduce risk or avoid potential triggers, especially for people who have already experienced one SCAD event.
Managing blood pressure carefully is important, as dangerously high blood pressure can stress artery walls. People at risk for SCAD should work with their healthcare providers to keep blood pressure well-controlled through medication if needed, dietary changes such as reducing salt intake, maintaining a healthy weight, and managing stress. Regular blood pressure monitoring helps ensure that it stays within a safe range.[6]
Avoiding extreme physical exertion may help reduce SCAD risk. While regular moderate exercise is generally beneficial and encouraged, activities that cause sudden, intense increases in blood pressure should be approached cautiously. This includes avoiding very heavy lifting that requires prolonged straining, extreme endurance training, and elite competitive sports. Activities involving sudden acceleration and deceleration, such as bungee jumping, skydiving, motocross riding, or go-karting, should also be avoided. Physical activity recommendations should be individualized based on a person’s baseline fitness level and medical history.[19][20]
Certain yoga and Pilates movements that involve aggressive neck positioning or stretching should be avoided, as should all forms of spinal manipulation by chiropractors or osteopaths. These activities could potentially stress blood vessels in ways that might trigger dissection in susceptible individuals.[19]
Quitting smoking is strongly recommended to protect the cardiovascular system overall. While smoking has not been definitively linked as a direct SCAD trigger, it damages blood vessels in general and increases risk for many types of heart and vascular problems. People at risk for SCAD should avoid smoking and exposure to secondhand smoke.[20]
Managing emotional stress is also important. While it is impossible to eliminate all stress from daily life, developing healthy coping mechanisms, seeking mental health support when needed, and practicing stress-reduction techniques may help reduce the impact of emotional triggers. This might include counseling, meditation, deep breathing exercises, or other relaxation practices.[6]
For individuals with conditions known to increase SCAD risk, such as fibromuscular dysplasia or connective tissue disorders, regular medical follow-up and management of these underlying conditions is important. Screening for associated conditions after a SCAD diagnosis can help identify and manage additional risk factors.[3]
There is no known association between diet and SCAD specifically, though maintaining overall heart health through a balanced diet is beneficial. It is recommended that people avoid excessive caffeine and caffeinated energy drinks, as these can cause sudden increases in heart rate and blood pressure.[20]
How SCAD Affects the Body
Understanding what happens in the body during coronary artery dissection helps explain why this condition is so serious and requires urgent treatment. The process involves specific changes in the normal structure and function of the coronary arteries and the heart muscle they supply.
The coronary arteries are the blood vessels responsible for delivering oxygen-rich blood to the heart muscle itself. There are three main coronary arteries: the left anterior descending artery, the left circumflex artery, and the right coronary artery. These arteries branch off from the main artery leaving the heart and then divide into smaller branches that spread across the surface of the heart muscle and penetrate into it. The left anterior descending artery is the most commonly affected vessel in SCAD cases, particularly the middle and distal (farther) segments of this artery.[4][17]
Each coronary artery wall consists of three layers. The innermost layer, called the intima, is smooth and lines the inside of the blood vessel where blood flows. The middle layer, or media, contains muscle cells and elastic tissue that gives the artery strength and flexibility. The outermost layer, the adventitia, is connective tissue that contains tiny blood vessels called vasa vasorum that nourish the artery wall itself. In SCAD, the dissection can occur between any of these layers, causing them to separate.[3]
When a dissection begins, either through an intimal tear or bleeding from the vasa vasorum, blood enters the space between the layers of the artery wall. This creates two channels: the original channel where blood normally flows, called the true lumen, and a new abnormal channel between the separated layers, called the false lumen. As blood continues to accumulate in the false lumen, it forms an intramural hematoma, which is essentially a bruise within the artery wall.[7][12]
The growing hematoma puts pressure on the true lumen from the outside, narrowing or completely blocking the normal blood flow channel. Sometimes a flap of loose tissue develops where the layers have separated, which can further obstruct blood flow. Blood may also clot within the false lumen, adding to the compression of the true lumen. The result is reduced or completely blocked blood flow to the area of heart muscle supplied by that artery.[1]
When heart muscle does not receive adequate blood flow, it becomes starved of oxygen, a condition called ischemia. If this continues, the affected heart muscle cells begin to die, which is what constitutes a heart attack or myocardial infarction. The extent of heart damage depends on several factors: which artery is affected, how large the area of muscle supplied by that artery is, how completely the blood flow is blocked, and how quickly treatment is provided to restore blood flow.[4]
In SCAD patients, the arteries often have fragile walls but typically do not show the fatty deposits and calcification seen in atherosclerotic heart disease. This means that unaffected segments of the coronary arteries usually appear smooth and disease-free when examined by imaging. However, this also means that dissections can propagate or extend more easily along the artery because there is no hard plaque to limit the spread of the tear.[4][12]
The electrical system of the heart can also be affected when heart muscle becomes ischemic. This can lead to abnormal heart rhythms, or arrhythmias, which may be dangerous. In severe cases, the heart’s pumping function can be so compromised that the person develops heart failure, where the heart cannot pump enough blood to meet the body’s needs. The most serious possible outcome is cardiac arrest, where the heart stops beating effectively, which can lead to sudden death if not treated immediately.[1][4]
Interestingly, in many SCAD cases where the dissection is not too extensive and the patient survives the acute event, the artery has the potential to heal on its own over time. The body can reabsorb the hematoma and the layers of the artery wall can seal back together, restoring normal blood flow. This capacity for spontaneous healing is one reason why conservative medical management without invasive procedures is often preferred when the patient is stable. However, healing takes time, typically weeks to months, and careful monitoring is needed during this period.[13]
