A heart attack is often associated with traditional cardiovascular risk factors such as high cholesterol, high blood pressure, smoking and diabetes. However, not all heart attacks happen this way.
Spontaneous coronary artery dissection (SCAD) is an important and often misunderstood cause of heart attack, particularly in younger and middle-aged women. It can occur in people who are otherwise fit and healthy, with few or none of the traditional cardiovascular risk factors.
Understanding SCAD is important, not only for recognising its symptoms but also for supporting recovery and long-term cardiovascular health.
What is SCAD?
Spontaneous coronary artery dissection (SCAD) occurs when a separation develops within the wall of a coronary artery – the blood vessels responsible for supplying oxygen-rich blood to the heart muscle.
SCAD can occur through two proposed mechanisms. A tear in the inner layer of the artery (intima) can allow blood to enter the arterial wall. Alternatively, bleeding from the small vessels within the artery wall (vasa vasorum) can result in a collection of blood known as an intramural haematoma, without an identifiable intimal tear.
As blood accumulates within the arterial wall, it can create a secondary channel or space, referred to as a false lumen. This can compress the original channel through which blood flows (the true lumen), restricting or obstructing blood supply to the heart muscle.
When coronary blood flow is significantly reduced, the affected heart muscle may become damaged, resulting in a heart attack (myocardial infarction).
Unlike a typical heart attack, which most commonly occurs when atherosclerotic plaque ruptures and a blood clot obstructs blood flow, SCAD involves a problem within the artery wall itself.
Who does SCAD affect?
SCAD predominantly affects women, often occurring in younger and middle-aged adults, although it can also affect men and people outside this age range.
One of the most important things to understand about SCAD is that it frequently affects people without the traditional cardiovascular risk factors associated with heart attacks.
Several conditions and factors have been associated with SCAD:
Female sex and hormonal influences: SCAD occurs predominantly in women, with some cases associated with pregnancy and the postpartum period.
Fibromuscular dysplasia (FMD): A condition affecting the walls of arteries, which is commonly identified in people with SCAD.
Connective tissue disorders: Certain inherited conditions affecting connective tissue may be associated with arterial vulnerability, although these account for a relatively small proportion of cases.
Physical and emotional stress: Some SCAD events occur following intense physical exertion or significant emotional stress. These may act as precipitating factors in some individuals, although a direct causal relationship has not been established.
Pregnancy: Pregnancy-associated SCAD is an important consideration, particularly during the postpartum period.
It is important to recognise that these are associations rather than definitive causes. SCAD can occur in people with none of these identifiable factors.
What are the symptoms of SCAD?
SCAD can present in much the same way as a conventional heart attack.
Symptoms may include:
Chest pain, pressure or tightness.
Pain radiating into the arm, shoulder, back, neck or jaw.
Shortness of breath.
Nausea or vomiting.
Dizziness or light-headedness.
Sweating or unusual fatigue.
Symptoms can vary between individuals, and not everyone experiences the same presentation.
SCAD is a medical emergency. Anyone experiencing symptoms suggestive of a heart attack should seek immediate medical attention by calling 000 in Australia. Symptoms should never be dismissed because someone is young, physically active or has no known cardiovascular risk factors.
How is SCAD diagnosed?
SCAD can be challenging to diagnose because its symptoms are similar to those of other types of heart attacks.
Initial investigations generally include:
Electrocardiogram (ECG): Assesses the electrical activity of the heart and can identify changes associated with reduced blood supply. An ECG does not independently diagnose SCAD.
Blood tests: Cardiac troponin levels are measured to identify damage to the heart muscle.
Coronary angiography: Uses contrast dye and X-ray imaging to visualise the coronary arteries and identify areas of dissection or restricted blood flow.
Coronary angiography is generally the initial diagnostic investigation. In some cases, additional imaging techniques, such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT), may be used to clarify the diagnosis and assess the artery wall.
These investigations are not routinely required in every case, as instrumentation within a coronary artery affected by SCAD can carry additional risks, including further dissection.
Following diagnosis, screening of other arterial territories may be considered to identify associated vascular conditions, particularly fibromuscular dysplasia (FMD), which can affect arteries outside the heart.
How is SCAD treated?
Treatment depends on the location and extent of the dissection, the amount of blood flow affected and the person's clinical stability.
Unlike a typical heart attack caused by atherosclerotic plaque, SCAD often heals naturally over time. For this reason, a conservative management approach is generally preferred when the person is clinically stable and there is no ongoing evidence of significant ischaemia.
Conservative management may involve:
Medication to manage symptoms and support cardiovascular health.
Blood pressure management.
Monitoring during the acute recovery period.
Follow-up with a cardiologist experienced in SCAD.
Although conservative management is generally preferred, patients require careful monitoring during the acute phase, as the dissection can occasionally extend or compromise blood flow further.
In some circumstances, an intervention may be necessary to restore blood flow. This can include coronary stenting or, less commonly, coronary artery bypass surgery.
Stenting can be more technically challenging in SCAD because the dissection involves the artery wall itself. It is therefore generally reserved for situations where the benefits of intervention outweigh the risks.
Recovery after SCAD
Recovery following SCAD involves more than allowing the coronary artery to heal.
Although many people experience good physical recovery, the experience of having an unexpected heart attack can have a significant emotional and psychological impact.
People may experience:
Ongoing fatigue or reduced exercise tolerance.
Chest discomfort or recurrent chest pain.
Anxiety about physical activity and the possibility of another event.
Reduced confidence in their body's ability to tolerate exercise.
Uncertainty about returning to work, sport and everyday activities.
Recurrent chest discomfort is relatively common following SCAD. Importantly, chest pain does not necessarily indicate another dissection. However, new or concerning symptoms should always be medically assessed rather than automatically attributed to the original event.
SCAD can also recur, making ongoing cardiology follow-up and appropriate management important.
Recovery is individual, and rebuilding confidence can take time.
Exercise after SCAD: Is it safe?
One of the most common concerns following SCAD is whether it is safe to return to exercise.
Understandably, people may feel apprehensive about increasing their heart rate or placing additional demands on their cardiovascular system after experiencing a heart attack.
However, avoiding exercise altogether is not recommended.
Exercise plays an important role in cardiovascular health, physical function, mental wellbeing and long-term recovery. Cardiac rehabilitation is therefore an important component of care following SCAD.
Aerobic exercise
Regular, moderate-intensity aerobic exercise is generally encouraged following medical clearance.
Walking, cycling and other forms of steady aerobic activity can help improve cardiovascular fitness, exercise tolerance and confidence with movement.
Published exercise recommendations suggest working towards approximately 30–40 minutes of moderate-intensity aerobic activity on most days of the week, where clinically appropriate.
Exercise intensity should be individualised, taking into consideration cardiac function, symptoms, blood pressure response, medications and previous activity levels.
Resistance training
Resistance training can also be incorporated into rehabilitation, although it requires careful consideration of exercise selection, resistance and technique.
Generally, recommendations include:
Starting with low resistance and gradually progressing.
Using controlled movements and appropriate breathing techniques.
Avoiding maximal lifting and heavy straining.
Avoiding the Valsalva manoeuvre (holding your breath while lifting).
Allowing adequate recovery between exercises.
There are no universally established weight limits for all people recovering from SCAD. Resistance training should be prescribed according to individual clinical assessment, tolerance and goals.
Exercise considerations
Exercise recommendations following SCAD should be individualised, taking into consideration the extent of coronary involvement, recovery, symptoms and any co-existing vascular conditions.
For people with associated fibromuscular dysplasia (FMD), additional considerations may be necessary, particularly where the carotid or vertebral arteries are affected. This may include modifying activities involving extreme neck positions, forceful neck movements or significant mechanical loading.
Exercise progression should be guided by the treating cardiologist and an accredited exercise physiologist.
The importance of cardiac rehabilitation
Cardiac rehabilitation is an important part of recovery following SCAD.
Despite commonly affecting younger, otherwise healthy and physically active individuals, people recovering from SCAD may have questions about which exercises are appropriate and how to safely return to physical activity.
A tailored cardiac rehabilitation program can provide:
Individualised exercise prescription: Developing an appropriate aerobic and resistance training program based on clinical assessment and individual goals.
Monitoring and progression: Assessing exercise tolerance, symptoms, heart rate and blood pressure responses to guide progression.
Education: Understanding SCAD, cardiovascular health, exercise recommendations and long-term risk management.
Confidence with movement: Gradually rebuilding trust in the body and reducing fear associated with physical activity.
Ongoing support: Helping people return to the activities they enjoy and establish sustainable exercise habits.
Importantly, rehabilitation should consider both the physical and psychological aspects of recovery.
How can CardioCare Clinic help?
At CardioCare Clinic, we recognise that recovery following a cardiac event is about more than the heart itself. It is also about helping people regain confidence, return to the activities they enjoy and feel comfortable being physically active again.
We provide individualised exercise physiology services for people recovering from cardiovascular conditions, including SCAD.
Our approach considers your medical history, cardiac investigations, current symptoms, exercise tolerance and personal goals to develop an appropriate exercise program.
Whether you are returning to exercise for the first time following your diagnosis or looking to rebuild your previous fitness routine, we can support you through a gradual and clinically guided approach.
You don't have to navigate exercise after SCAD alone.