Cardiac Arrest

Cardiac arrest happens when your heart stops beating or beats so fast that it stops pumping blood. When your heart isn’t pumping blood, this puts your organs and whole body at risk of death within minutes because they need a constant supply of oxygen. Your blood delivers that oxygen.

With this condition, people typically collapse and can’t respond. Symptoms start without warning. This is why people also call this life-threatening condition sudden cardiac arrest.

Cardiac arrest (an electrical failure) isn’t the same as a heart attack. A heart attack happens when a blocked artery cuts off blood flow to heart muscle.

With cardiac arrest, your heart stops beating, but a rescue is still possible. With immediate treatment, you can survive. If someone doesn’t save you, it leads to sudden cardiac death.

Emergency treatment includes cardiopulmonary resuscitation (CPR) and defibrillation. CPR keeps oxygen flowing to your brain until an electric shock restores a normal heart rhythm. CPR and defibrillation (which delivers an electrical shock) may save your life.

About 350,000 Americans each year experience cardiac arrest outside of a hospital. It typically affects adults, but it can happen in children and teens, too.

Symptoms of cardiac arrest

Some people collapse without any other symptoms or warning signs. Right before you faint and have other signs of cardiac arrest, like lack of a pulse or breaths, you may have symptoms like:

• Chest pain or pressure
• Nausea and/or vomiting
• Shortness of breath
• Gasping or abnormal breaths
• Heart palpitations
• Dizziness
• Lightheadedness
• Sudden weakness

Cardiac arrest causes

Any condition that severely lowers oxygen levels, disrupts your heart’s electrical signals or keeps your heart from pumping well can lead to cardiac arrest. Abnormal heart rhythms (arrhythmias) cause most sudden cardiac arrests. Abnormal, rapid impulses abruptly override the normal electrical impulses that start your heartbeat.

In many cases, a chaotic rhythm, ventricular fibrillation (v-fib), takes over. When this happens, your heart quivers instead of pumping and blood flow stops. Without rapid treatment, you can die within minutes.

Other causes of cardiac arrest include:

• Coronary artery disease or CAD, the most common cause in adults
• Congenital (since birth) or acquired heart conditions, like thick heart muscle or problems in the heart’s electrical circuit
• Changes to your heart’s structure because of a heart attack, heart failure or valve or muscle problems
• Extreme injuries or blood loss
• Severe infections
• Severe breathing failure
• Toxins, drug overdose or a buildup of certain medications

Risk factors

Sudden cardiac arrest happens in people with and without heart disease. A family history of cardiac arrest, sudden death or fainting from unexplained causes can raise your risk. Having a heart attack or another heart condition can significantly increase your risk, too. Conditions that can increase the risk of sudden cardiac arrest include:

• Heart or blood vessel issues you were born with
• Heart valve disease
• Fainting
• Heart failure
• Thickened heart muscle (hypertrophic cardiomyopathy)
• Major changes in the amount of potassium and magnesium in your blood
• Blood clots blocking blood flow between your heart and lungs
• Quick fluid buildup around your heart
• Heart inflammation

How doctors diagnose this condition

Cardiac arrest symptoms begin suddenly, leaving little time for tests. The condition can become fatal within minutes. This is why quick action is essential.

Someone in cardiac arrest is usually unconscious, has no pulse, doesn’t respond and isn’t breathing. These signs are enough to make a diagnosis.

A first responder who does an electrocardiogram (EKG) will find an abnormal rhythm or no heartbeat. After a person is revived and stable, healthcare providers often find the cause of cardiac arrest by using:

• Blood tests
• Echocardiogram
• Coronary angiogram
• Genetic tests

How is it treated?

CPR plus defibrillation rescues a person from sudden cardiac arrest.

To treat cardiac arrest, first responders will:

1. Perform CPR: This replaces your heart’s pumping action and keeps blood and oxygen circulating.
2. Use an AED (automated external defibrillator): A shock (sometimes more than one) from paddles on your chest travels to your heart and restarts it. This stops the abnormal impulses and restores the normal impulses that make it beat.
3. Give you medications through an IV in your arm: These work to make your heart’s rhythm stable.
4. Get you to a hospital: You need hospital care to protect your brain, treat the cause of cardiac arrest and prevent another one.

Cardiac arrest treatment has to start right away, wherever you are. Brain injury can happen after just five minutes without oxygen. Survival drops sharply after eight to 10 minutes without CPR. Starting CPR in the first few minutes is the most important factor for survival.

What bystanders can do

The biggest difference in survival comes from what happens before first responders arrive. Early action by bystanders is the strongest predictor of better outcomes. If you see someone suddenly collapse and you suspect sudden cardiac arrest, do this:

1. Call 911 (or your local emergency services number) immediately.
2. Start CPR, even if it’s just the hands-only version.
3. Use an AED (which tells you what to do) if there’s one nearby. The sooner someone gets a shock, the higher the chance of survival.

What can I expect if I have cardiac arrest?

Surviving cardiac arrest is a major medical event. What happens next depends mostly on how quickly you get treatment. People who get immediate help have the best chance of returning to their normal lives. Recovery takes time. Steady improvement is common.

After returning home, you may have medical problems related to the arrest or its cause.

These may include:

• Heart issues that need long-term care
• Kidney or liver problems
• Fatigue or weakness that lasts weeks to months
• Thinking or memory problems
• Mood or emotional changes like anxiety or depression
• Speech or swallowing problems

You may need to go back to the hospital for treatments, depending on how your organs and brain recover. Severe cases may lead to a coma or long-term unconscious state. People often need rehabilitation to relearn how to walk or dress. This can take weeks to months.

Be patient with yourself as you slowly get back to doing the things you did every day. Many people improve steadily during the first six months.

When should I see my healthcare provider?

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 cardiac arrest.

Be sure to tell your provider if you’re having any new symptoms or aren’t feeling better during the expected time frame.

Questions to ask your provider may include:

• Do I need an AED to keep at home?
• Are there any programs available to help me get back to my normal activities?
• Is my family at risk for cardiac arrest?
• Should my family members or I undergo genetic testing?

Can a person survive after cardiac arrest?

Yes, you can survive cardiac arrest. But it’s not common. Most people who have sudden cardiac arrest outside of a hospital don’t survive. This is usually because they don’t get help in time.

Still, survival rates are better than they used to be. About 1 in 10 people who have cardiac arrest outside a hospital and get emergency treatment survive and go home from the hospital. About 1 in 4 people who have cardiac arrest inside a hospital survive and go home.

Can this be prevented?

Yes, it’s possible to lower your risk of cardiac arrest. You can do this by managing conditions that strain or damage your heart (like high cholesterol, high blood pressure and diabetes) and living a healthy lifestyle. This includes:

• Avoiding tobacco products and stimulants
• Eating heart-healthy foods
• Staying at a weight that’s healthy for you
• Being physically active on most days of the week
• Managing sleep apnea

If abnormal heart rhythms run in your family, you may want to talk with a genetic counselor. They can tell you who might be at risk or need a blood test to check for an issue that causes arrhythmia.

Checking for coronary artery disease or heart rhythm problems can let you know whether you’re at risk for sudden cardiac arrest.

How to prevent another episode

To prevent future episodes of sudden cardiac arrest, your healthcare provider will suggest tests to figure out why it happened. Tests may include:

• Electrocardiogram (ECG or EKG)
• Heart MRI (magnetic resonance imaging)
• Blood tests to check electrolytes
• Ambulatory monitoring
• Echocardiogram (echo)
• Cardiac catheterization
• Electrophysiology study

Treatments that can prevent cardiac arrest or lower your risk of a second episode include:

• Implantable cardioverter defibrillator (ICD)
• Catheter procedures like ablation
• Medicines like beta-blockers
• Fixing heart artery blockages with either coronary artery bypass surgery (CABG) or angioplasty
• Managing sleep apnea