Understanding Cardiac Arrest

Cardiac arrest is unique and represents the heart-brain connection

Cardiac arrest is a life-threatening condition in which the heart suddenly stops beating normally. In cardiac arrest, the heart cannot pump blood around the body to deliver oxygen and nutrients. This causes loss of normal pulse, difficulty breathing, and unconsciousness because the brain cannot get enough oxygen. Cardiac arrest can happen to anyone at any time, regardless of their age, sex, race, or ethnicity. Even children, teenagers, or seemingly healthy people without any history of heart issues can experience cardiac arrest. 

Over the last 10 years, more people have survived cardiac arrest. The chances of survival triple from 10% to 30% if: (1) the cardiac arrest is witnessed by someone else, (2) if the person experiencing cardiac arrest receives high-quality chest compressions or cardiopulmonary resuscitation (CPR), and (3) if the life-threatening heart rhythm is reversed using an automatic external defibrillator (AED), which is often publicly available. The chain of survival starts with somebody identifying cardiac arrest, calling 911, and starting chest compressions immediately to keep oxygenated blood pumping through the body.

Calling 911 brings additional medical help in the form of trained responders, who may give medications or provide transportation to a hospital, where other important treatments can be given. Once an AED arrives, it can be used to deliver a life-saving shock to stop the heart’s uncoordinated rhythm and allow it to begin pumping effectively again. 

Not everyone has access to an AED, and not everyone in cardiac arrest will need a shock. Continuing good, strong CPR until an AED arrives is the most important action. When a cardiac arrest happens, every second counts! The faster these life-saving measures are provided, the better the chances of survival.

How do I identify cardiac arrest?

Many people are confused about what cardiac arrest looks like. They may be scared they have mixed it up with something else, which prevents them from feeling confident about how to help. 

Someone who is in cardiac arrest will lose consciousness and not respond to touch or sound. Their skin may look pale, blue, or not their normal healthy color, and they will not breathe normally. Within the first few minutes of cardiac arrest, the person will most likely gasp, breathe irregularly, and make strange sounds. Their eyes may open and stare blankly, and they may lose control of their bladder. They might have sudden, jerky movements of their body, which could be mistaken for a seizure.

What causes cardiac arrest?

There are multiple factors that could cause someone’s heart to go into cardiac arrest. Coronary heart disease is the most common cause of cardiac arrest. Most people who had a cardiac arrest outside of a hospital had heart disease, although they may not have known it. The most common type of heart disease — coronary artery disease — is caused by cholesterol, a waxy substance that builds up inside the lining of the arteries feeding the heart and forming plaque. This buildup can partially or totally block blood flow in the large arteries feeding the heart and lead to cardiac arrest.

Cardiac arrest can also occur in children after respiratory arrest (when breathing has stopped) due to choking or drowning. Some people are born with abnormal heart development, rhythm, or function and do not know it until a cardiac arrest occurs. Additionally, severe injuries and blood loss, breathing abnormalities, infections, blood clots, and drug overdoses can lead to cardiac arrest.

Sometimes the cause of cardiac arrest is unknown.

Can it happen to me?

This is a question almost everyone touched by cardiac arrest asks, and with good reason. The short answer is: It depends on the cause. Cardiac arrest can happen to anyone without any warning. However, medical professionals diagnose the cause of cardiac arrest and prevent it from happening again. This might include genetic testing to identify the cause, medications, procedures to remove blockages in the heart, and/or surgeries to place a pacemaker (to correct an abnormally slow heart rhythm) or implantable cardioverter defibrillator (to monitor your heart and, if needed, shock it out of an abnormal heart rhythm).

In cases where the cause of the cardiac arrest can be avoided in the future (for example, choking, drowning, overdose, certain medications), the potential for repeat cardiac arrest is very low.

What is the difference between cardiac arrest and a heart attack?

Cardiac arrest and a heart attack are not the same thing, and the terms are often mistakenly used interchangeably. Compared to cardiac arrest, which is an electrical problem causing the heart to stop beating, a heart attack is a physical blockage in the arteries supplying the heart that disrupts blood flow. A heart attack prevents the heart from receiving oxygen and nutrients, causing parts of the heart muscle to die. If left untreated, a heart attack can cause the heart to stop beating, and the person will then go into cardiac arrest. Someone who is having a heart attack can still be conscious, breathing, and speaking, because their heart has not stopped beating.

What is the difference between cardiac arrest and a stroke?

Cardiac arrest and a stroke are not the same thing. Cardiac arrest is an electrical problem that happens when the heart stops beating, which stops blood flow to the brain and other organs. A stroke happens when blood flow to part of the brain is interrupted, damaging the brain. It is typically caused by either a blockage or blood clot in the brain (ischemic stroke) or by an artery that breaks open and causes a brain bleed (hemorrhagic stroke).

Sources

Cardiac Arrest Causes & Risk Factors: https://www.nhlbi.nih.gov/health/cardiac-arrest/causes

Heart Attack & Cardiac Arrest Differences: https://www.heart.org/en/health-topics/heart-attack/about-heart-attacks/heart-attack-or-sudden-cardiac-arrest-how-are-they-different

About Stroke: https://www.stroke.org/en/about-stroke

Thank you to our contributors

Samantha Fernandez & Katrysha Gellis