Cardiac Arrest | Heart and Vascular

Heart and Vascular Care

Cardiac Arrest

As leaders in cardiac care and emergency medicine, we treat hundreds of patients who present with cardiac arrest each year. Our team has the skill and technology to rapidly address any life-threatening heart condition.

Medically reviewed by Jeffrey Southard, M.D. on Aug. 17, 2023.

Man on the phone while another man lays on the ground grasping his chest.

What Is Cardiac Arrest?

Your heart has its own electrical system that controls your heartbeat. Cardiac arrest occurs when this electrical system malfunctions and your heart suddenly stops beating.

Cardiac arrest is not a heart attack. Most heart attacks happen when a blood clot or plaque buildup blocks blood flow to your heart. A heart attack can cause cardiac arrest, but many cases of cardiac arrest occur without a heart attack.

Cardiac arrest is a life-threatening emergency. At UC Davis Health, we're always prepared to provide the most advanced care for patients who suffer a cardiac arrest. Our Emergency Department and cardiovascular teams work together to provide critical care for the most serious heart problems. 


Cardiac Arrest Symptoms

Cardiac arrest symptoms are sudden and unexpected. Many people don’t feel any symptoms before the cardiac arrest occurs. If they do, these symptoms often last only a few seconds before the person collapses.

Any sign of cardiac arrest is a medical emergency. If you see someone with symptoms of cardiac arrest, act fast. Call 911 and have someone begin cardiopulmonary resuscitation (CPR) while you wait for first responders to arrive. If you have access to an automated external defibrillator (AED), use it right away. 

First Symptoms

People who notice symptoms right before their cardiac arrest might feel:

  • Dizzy or faint
  • Short of breath
  • Sick to their stomach
  • Weak

Emergency Symptoms

Symptoms of cardiac arrest are always an emergency. Call 911 immediately if someone:

  • Suddenly collapses
  • Cannot wake up or respond to others
  • Is not breathing
  • Doesn’t have a pulse (but don’t take extra time trying to find a pulse)

Causes of Cardiac Arrest

Half of all cardiac arrests happen to people with no known heart problems. But certain factors can lead to cardiac arrest, including:


An arrhythmia is an abnormal heart rhythm. Common arrhythmias that lead to cardiac arrest are ventricular tachycardia and ventricular fibrillation. These conditions cause an irregular rhythm in your heart's ventricles (lower chambers).

Blood Vessel Abnormalities

A congenital heart defect can affect your aorta or coronary artery and may trigger sudden cardiac arrest. Often, cardiac arrest happens during intense exercise.


Cardiomyopathy is a condition caused by thickened heart muscles. This condition makes it harder for the heart to pump blood normally and the fibers of the heart might not be normal, which can lead to sudden cardiac arrest.

Coronary Artery Disease (CAD)

Coronary artery disease happens when plaque builds up in your arteries, the pipes that bring oxygen and nutrients to your heart muscle. The plaque can block blood flow to your heart and cause a heart attack. When some of the heart muscle is damaged, this can lead to cardiac arrest.

Heart Failure

If you have heart failure, your heart isn’t pumping enough blood for your body’s needs. This condition can disrupt your heart’s rhythm, leading to cardiac arrest.


Some medications, such as narcotic painkillers, can cause cardiac arrest. Talk to your provider about any medications you take, and don’t stop taking medications without your provider’s advice.

Recreational Drug Use

Cocaine, methamphetamines and ecstasy are a few examples of drugs that can cause cardiac arrest. Opioid overdose is also a leading cause of cardiac arrest and death.

Scarring of the Heart

A previous heart attack can cause scarring of the heart, which can lead to abnormal electrical activity and cause cardiac arrest. Long-term high blood pressure can also cause scarring of your heart and lead to cardiac arrest.

Structural Heart Problems

You can be born with differences in your heart’s shape and structure. These abnormalities can lead to sudden cardiac arrest in some cases.


A forceful hit to the chest can cause sudden cardiac arrest. Other trauma, such as serious vehicle accidents or electrocution, can also cause the heart to suddenly stop.


Risk Factors for Cardiac Arrest

People of all ages and ethnicities can experience cardiac arrest, but certain people may have a higher risk. Cardiac arrest risk factors include:


People over age 30 experience cardiac arrest more frequently than younger people.

Heart Disease

If you have any type of heart disease or a family history of heart problems, you may have a higher risk of cardiac arrest.

Other Health Conditions

Cardiac arrest tends to occur more often in people with other health problems like diabetes or chronic kidney disease.

Race or ethnicity

People who are Black or African American experience cardiac arrest more often than people of other races.


Diagnosing Cardiac Arrest

Cardiac arrest occurs without warning, so first responders and emergency medical teams often diagnose it. They check your vital signs, including your pulse and breathing, and begin lifesaving care if they suspect cardiac arrest.

UC Davis Emergency Department staff are ready for these life-threatening situations. As a level 1 trauma center, we handle hundreds of cases of cardiac arrest each year. We combine our expertise and experience with advanced technology to provide rapid care.

Once you are stable, we guide your follow-up care with our leading heart and vascular specialists. To find the cause of cardiac arrest, we perform a thorough evaluation, which may include:

Blood tests

A sample of your blood can identify electrolyte imbalances or toxic substances that can cause cardiac arrest.

Cardiac catheterization

This test uses a catheter (thin tube) with a camera to see inside your heart.

Electrocardiogram (EKG)

This noninvasive imaging test shows how your heart’s electrical system is working.

Genetic tests

If our providers suspect you could have a genetic condition, we may run genetic tests. Then, our genetic counselors explain your results.

Imaging tests

A cardiac CT scan, MRI or echocardiogram provides detailed images of your heart and can reveal structural heart disease.

Cardiac Arrest Treatments at UC Davis Health

Our highly trained emergency department team is always ready for the most serious health conditions. If you are experiencing cardiac arrest, our team takes immediate action. Your treatment may include:


Our staff uses specialized defibrillation equipment with the goal of restarting your normal heart rhythm.


In some cases, medications can treat irregular electrical activity, called an arrhythmia, or restore electrolyte levels. If you have an opioid overdose, we provide Naloxone, which reverses the opioid’s effects if you receive it soon after the overdose.

Surgery and Procedures

You may need a heart procedure or surgery to remove a blockage that is stopping blood flow to your heart. We also perform advanced trauma surgery if you have been in an accident.


Preventing Cardiac Arrest

You cannot always prevent cardiac arrest. But you can lower your risk by seeing your health care provider regularly. During checkups, your primary provider listens to your heart and can refer you to a specialist if anything seems abnormal. They also screen you for diabetes, high blood pressure and other conditions that raise your risk of cardiac arrest.

If you have any heart disease in your family, ask your provider whether you need tests or treatments. Talk with them about ways you can prevent types of heart disease that can lead to cardiac arrest, such as heart attack or high blood pressure.  

"What Is Cardiac Arrest?" National Institutes of Health (NIH),

"Association of Cardiac Arrest With Opioid Overdose in Transport," NIH, 

Who does it affect?

436KU.S. adults and children die from cardiac arrest each year

Early CPR gives a person

3XMore chances for survival after cardiac arrest

Source: American Heart Association: CPR Facts and Stats

Request an Appointment

As Sacramento's No. 1 hospital, you'll benefit from unique advantages in primary care and specialty care. This includes prevention, diagnosis and treatment options from experts in 150 specialties.

Referring Physicians

To refer a patient, you can submit an electronic referral form or call.



For questions and appointment information

Awards and Recognitions
USNWR Best Hospital badge

Ranked among the nation’s best hospitals

A U.S. News & World Report best hospital in cancer, cardiology, heart & vascular surgery, diabetes & endocrinology, ENT, geriatrics, neurology & neurosurgery, obstetrics & gynecology, and pulmonology & lung surgery.

Learn more
US News & World Report best Children’s Hospital badge

Ranked among the nation’s best children’s hospitals

A U.S. News & World Report best children’s hospital in diabetes & endocrinology, nephrology, and orthopedics*. (*Together with Shriners Children’s)

Learn more
USNWR best regional hospital badge

Ranked Sacramento’s #1 hospital

Ranked Sacramento’s #1 hospital by U.S. News, and high-performing in COPD, colon cancer surgery, diabetes, heart attack, heart failure, hip fracture, hip replacement, kidney failure, leukemia, lymphoma & myeloma, lung cancer surgery, ovarian cancer surgery, pneumonia, prostate cancer surgery, stroke, TAVR, uterine cancer surgery, gastroenterology & GI surgery, and orthopedics.

Learn more
Magnet designation badge

The nation’s highest nursing honor

UC Davis Medical Center has received Magnet® recognition, the nation’s highest honor for nursing excellence.

Learn more
Chime acute badge

“Most Wired” for acute care

UC Davis Health has been recognized as a level 10 out of 10 in the Digital Health “Most Wired” program from the College of Healthcare Information Management Executives (CHIME). The honor recognizes excellence in using technology to improve the delivery of care.

Learn more
Chime ambulatory badge

“Most Wired” for ambulatory care

UC Davis Health has been recognized as a level 10 out of 10 in the Digital Health “Most Wired” program from the College of Healthcare Information Management Executives (CHIME). The honor recognizes excellence in using technology to improve the delivery of care.

Learn more
NCI badge

World-class cancer care

One of ~56 U.S. cancer centers designated “comprehensive” by the National Cancer Institute.

Learn more

A leader in health care equality

For the 11th consecutive year, UC Davis Medical Center has been recognized as a “Leader in LGBTQ+ Healthcare Equality.”

Learn more
See more