Your heartbeat is made up of electrical impulses that allow your heart to pump in a specific rhythm. This is how blood circulates through the heart and back out to the rest of the body with oxygen and nutrients to support the organs and tissues. But a disruption in the electrical impulses that control the heart’s pumping actions can happen suddenly and can be deadly. An abnormal heart rhythm, called an arrhythmia, can lead to sudden cardiac arrest. In cardiac arrest, a person loses consciousness and stops breathing. A heart attack can lead to cardiac arrest, but it is not the same thing. A heart attack is a circulation problem where blood flow to the heart is blocked, while cardiac arrest is an electrical problem where the heart stops beating.

Heart Attacks and Other Causes of Cardiac Arrest

A heart attack is one cause of cardiac arrest. Heart attacks happens when there is restriction or blockages in an artery or arteries that supply blood to the heart muscle. Without blood flow, the heart’s muscle is damaged and can produce abnormal rhythms.

Data from the Centers for Disease Control and Prevention (CDC) shows 2,000 people under the age of 25 die each year of sudden cardiac arrest. 

“Heart attack due to coronary artery disease (CAD) is a common cause of cardiac arrest in older adults,” said Kiran Kashyap, MD, an interventional cardiologist with the Froedtert & the Medical College of Wisconsin health network. “In young people, the most common causes of cardiac arrest are cardiomyopathy, congenital heart disease, genetic rhythm disorders, heart inflammation and substance abuse. It is unusual for a young person to go into cardiac arrest because of a heart attack.” 

Causes of cardiac arrest:

  • Coronary artery disease: restriction or blockage in an artery or arteries of the heart 
  • Coronary artery spasm: narrowing of the artery that sends blood to the heart
  • Arrhythmia: heart rhythm disorders
  • Congenital heart disease: people who are born with heart defects
  • Genetic disorders of the heart muscle, such as hypertrophic cardiomyopathy, which leads to thickening of the heart muscle
  • Heart failure
  • Structural heart disease: defects or disorders that affect the heart’s valves, muscles, walls or chambers
  • Inflammation of the heart muscle, which can be due to disease, viral infection or substance abuse
  • Blunt chest injury

Recognize a Heart Attack or Cardiac Arrest

During a heart attack, the heart continues to beat but the blockage in the artery prevents blood flow. When a person is in cardiac arrest, the heart stops beating. Cardiac arrests and heart attacks are emergency situations. If you think someone is experiencing one of these heart problems, call 911 immediately.
Heart attack symptoms can seem mild at first, before the situation becomes urgent.

The most common heart attack symptoms are:

  • Chest pain, pressure or discomfort
  • Pain in the arms, jaw, back, neck or stomach
  • Shortness of breath
  • Nausea
  • Breaking out in a cold sweat

Women and men may present with different symptoms. For men, chest pain is the most common symptom. Women often experience other symptoms that don’t always appear heart attack-related, such as fatigue, back or jaw pain and nausea. A person having a heart attack needs to go to the nearest hospital immediately to treat the blocked artery and restore blood flow.

Cardiac arrest can happen very suddenly. Common cardiac arrest symptoms are:

  • Sudden collapse or loss of consciousness
  • Person is unresponsive
  • No pulse
  • Not breathing

If you think a person is in cardiac arrest, call 911 and start chest compressions immediately. CPR uses chest compressions to help keep blood flowing throughout the body while the heart is stopped. 

“The faster the person gets CPR, the more likely they are to survive,” Dr. Kashyap said. “Also, the better the recovery is for heart, brain and other organs. Preventing oxygen deprivation to the brain is critical during a cardiac arrest.”

Hands-Only CPR

According to the American Heart Association, 90% of people who suffer a cardiac arrest outside of a hospital die. If CPR is done immediately, it can double or triple the person’s chances of survival. Hands-only CPR is an easy method to learn that requires very little training and is without mouth-to-mouth breaths. Hands-only CPR has been shown to be just as effective as conventional CPR during the first few minutes of a heart attack outside of a hospital.

After calling 911, immediately begin chest compressions, pushing hard and fast in the center of the chest at a rate of 100 to 120 compressions per minute. Use the beat of a familiar song like “Stayin’ Alive” by the Bee Gees to help you stay in rhythm. Watch these videos by the AHA for a demonstration. 

Treatment for Cardiac Arrest

Cardiac arrest requires emergency medical attention. Doctors will need to diagnose the cause to determine the best treatment.  

“We do a thorough workup,” Dr. Kashyap said. “We gather history of current symptoms, medical conditions the patient has and any medications the patient may be taking. We order blood tests, an electrocardiogram (EKG) and use imaging such as echocardiogram, CT scan and cardiac MRI. We also do a cardiac catheterization procedure to assess blood flow to the heart.”

Interventional cardiologists specialize in procedures to treat blocked blood vessels in the heart. When a blocked blood vessel causes cardiac arrest, minimally invasive, catheter-based techniques are often used to restore blood flow quickly. 

Electrophysiologists are specialists who are experts in the electrical system of the heart and treat heart rhythm disorders. For heart rhythm problems that cause cardiac arrest, a wide range of treatment options is available, from medication to minimally invasive procedures such as ablation, as well as surgery to implant long-term devices like defibrillators. 

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