Sudden cardiac arrest is an emergency in which your heart suddenly stops beating. An electrical issue makes your heart stop pumping blood. This leaves your cells unable to receive the oxygen they need. Because of the lack of oxygen to your cells, sudden cardiac arrest can turn fatal in just minutes. Survival odds are best when help is immediate.
Sudden cardiac arrest is a life-threatening condition in which your heart comes to a standstill. Your heart isn’t pumping blood anymore. Within minutes, this puts your organs and whole body at risk of death. They must constantly receive oxygen. Your blood delivers that oxygen.
Emergency treatment includes cardiopulmonary resuscitation (CPR) and defibrillation. CPR keeps enough oxygen in your lungs and gets it to your brain until an electric shock restores a normal heart rhythm. CPR and defibrillators may save your life.
Call 911 if you see someone drop to the ground and you suspect sudden cardiac arrest. The faster emergency measures, including CPR and defibrillation are administered, the higher the chances of survival with good health outcomes.
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Sudden cardiac death (SCD) is a sudden, unexpected death. A loss of heart function (sudden cardiac arrest) causes it. Sudden cardiac death is the largest cause of natural death in the United States. It causes about 325,000 adult deaths in the nation each year. Sudden cardiac death is responsible for half of all heart disease deaths.
Sudden cardiac death occurs most frequently in adults in their mid-30s to mid-40s. It affects men and people assigned male at birth (AMAB) twice as often as it does women and people assigned female at birth (AFAB). This condition is rare in children, affecting only 1 to 2 per 100,000 children each year.
When you have a sudden cardiac arrest, your body’s organs can’t receive any oxygen. Without immediate help to get oxygen to your brain and other vital organs, this is fatal.
Some people have chest pain during the initial seconds of sudden cardiac arrest. However, once you lose consciousness, you don’t feel pain.
Sudden cardiac arrest happens when your:
As a result of these electrical changes to your heart, it can’t pump blood, and blood doesn’t reach the rest of your body. As a result, this condition is fatal unless emergency treatment starts immediately.
In the first few minutes, the greatest concern is that blood flow to your brain will be so limited that you’ll lose consciousness.
Sudden cardiac arrest isn’t a heart attack (myocardial infarction).
Heart attacks happen when there’s a blockage in one or more of your coronary arteries. This prevents your heart from receiving enough oxygen-rich blood. When oxygen in your blood can’t reach your heart muscle, you can have heart damage.
Sudden cardiac arrest has many risk factors, especially coronary heart disease. However, you’re more likely to have a higher risk as you age and if you’re African-American and AMAB. Certain genetic causes of heart disease such as hypertrophic cardiomyopathy also increase the risk of sudden cardiac death.
An estimated 74 people out of 100,000 received emergency treatment for cardiac arrest outside a hospital in 2018. Also, an estimated 1 out of 7 people died from sudden cardiac death in America in 2017.
In more than half of the cases, sudden cardiac arrest happens without prior symptoms.
Sudden cardiac arrest symptoms may include:
This means that a potentially dangerous heart rhythm problem has started, which is why these are also sudden cardiac death symptoms.
Abnormal heart rhythms called arrhythmias cause most sudden cardiac arrests. The most common life-threatening arrhythmia is ventricular fibrillation. This is an erratic, disorganized firing of impulses from your heart’s ventricles (lower chambers). When this happens, your heart is unable to pump blood. Without treatment, you can die within minutes.
Other sudden cardiac arrest causes include:
Coronary artery disease causes most cases (80%) of sudden cardiac death. In people who are younger, congenital (since birth) heart defects or genetic abnormalities in their heart’s electrical system are often the cause. In people age 35 and older, the cause is more often related to coronary artery disease.
Other sudden cardiac death causes include cardiomyopathy from:
Sudden cardiac death in athletes is rare (about 1 in 100,000 to one in 300,000 athletes). Most professional athletic programs will screen their prospective athletes for the most common causes of sudden cardiac death in that population, which in the United States is hypertrophic cardiomyopathy. It also happens more often in people AMAB.
In people who are younger, most sudden cardiac death occurs while playing team sports. In athletes age 35 and older, it happens more often while running or jogging. About 1 in 15,000 joggers and 1 in 50,000 marathon runners have sudden cardiac death.
Many factors can increase your risk of sudden cardiac arrest and sudden cardiac death.
The two leading risk factors include:
Other risk factors include:
If you have any of these risk factors, it’s important to speak with your healthcare provider about how to reduce your risk.
Your healthcare provider can diagnose a sudden cardiac arrest if you:
Many cases of sudden cardiac arrest are diagnosed post-mortem, as this condition is often fatal.
To prevent future episodes of sudden cardiac arrest, your healthcare provider will want to do tests to figure out what caused your cardiac event. Tests may include:
You can treat and reverse sudden cardiac arrest. However, emergency action has to start immediately. Survival can be as high as 90% if treatment starts within the first minutes after sudden cardiac arrest. The rate drops by about 10% each minute longer.
If you see someone experiencing sudden cardiac arrest, do this:
Once emergency personnel arrive, defibrillation can restart the person’s heart if they haven’t received a shock from an AED yet. Defibrillators shock your heart through paddles placed on your chest. Emergency personnel will also give intravenous medications called antiarrhythmics that work to restore the heart’s electrical rhythm.
After successful defibrillation, most people need hospital care to recover from the effects of their sudden cardiac arrest and to treat and prevent future cardiac problems.
You can reduce your risk in many ways, such as:
High school and college athletes should have a heart screening every two years. This should include an evaluation of their personal and family history (updated annually) and a physical exam. Their sports physician may recommend additional testing such as an electrocardiogram if there are any concerning findings on an initial evaluation.
If your healthcare provider suspects a heart problem, you should get a referral to a cardiologist.
Most people (about 90%) who have a sudden cardiac arrest outside of a hospital don’t survive. This is usually because they don’t get help in time. Most cases of sudden cardiac arrest that don’t happen in a hospital take place at home. Every minute that you don’t receive help is another minute your brain is without the oxygen it needs.
People who survive sudden cardiac arrest have a varied outlook, depending on how fast they received medical treatment. They usually need help regaining skills they had before their sudden cardiac arrest. This happens because you can have brain damage if too many minutes pass without oxygen reaching your brain. Other organs may also be affected, including resulting in kidney failure, liver failure and long-term heart disease.
Surviving sudden cardiac arrest is the start of a long recovery for many. Depending on how long your brain was without oxygen, you’ll likely have brain damage. This means you may not be able to do all the things you used to do every day. Also, you may have some mental health challenges like stress and depression.
If a rehabilitation program is available, you can use it to regain your abilities. This will take time and patience. Researchers have found that sudden cardiac arrest survivors’ quality of life got better after six months.
You’ll most likely have follow-up appointments with multiple healthcare providers as you recover from sudden cardiac arrest. You’ll also have procedures or treatments that can help prevent you from having another sudden cardiac arrest.
Be sure to tell your provider if you’re having any new symptoms or if you aren’t feeling better during the expected time frame.
If you witness someone collapsing into unconsciousness, call 911 to get help. Start CPR and send someone else to find an AED.
A note from Cleveland Clinic
Surviving sudden cardiac arrest is a stressful experience. You’ll need time to recover and work on being able to do the activities you did in the past. Keep your follow-up appointments with your healthcare provider. Don’t be afraid to ask questions if there’s something you don’t understand. You may feel safer if your family takes a CPR class so they can help you if you have another sudden cardiac arrest.
Last reviewed by a Cleveland Clinic medical professional on 06/06/2022.
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