For someone who has never experienced sudden cardiac arrest, it’s natural to wonder what cardiac arrest feels like. If you have a family history of coronary artery disease, someone in your family had a heart attack or cardiac arrest, or you want to be able to identify and treat heart symptoms early, understanding cardiac arrest and the associated symptoms can help you to be more prepared.
Most People Feel Nothing When Experiencing Cardiac Arrest
Around half of SCA victims don’t feel anything when they go into cardiac arrest. Their heart’s electrical system malfunctions, their heart stops beating, they stop breathing, and they lose consciousness and collapse. Once the person loses consciousness, they feel no pain.
If you’ve ever fainted, you might have some idea of what cardiac arrest feels like. You’re going about your daily business when you start to feel a bit lightheaded or dizzy, and next thing you know, you’re waking up to concerned faces with no memory of what just happened or how long you’ve been out.
Half of Cardiac Arrest Victims Experience Warning Signs
For the other half of cardiac arrest victims, there are warning signs before the collapse.
Immediately before losing consciousness, you might feel:
- Weak, dizzy, or lightheaded
- Heart palpitations or a racing heartbeat
Within the hour before losing consciousness, some people feel:
- Chest pain
- Shortness of breath
- Feeling sick to the stomach (nausea)
Why Do These Cardiac Arrest Symptoms Occur?
When someone goes into sudden cardiac arrest, the heart’s electrical system fires erratically, causing the heart muscle to stop pumping blood around the body. The most common direct cause is often one of two AED-shockable ventricular arrhythmias: ventricular fibrillation and pulseless ventricular tachycardia.
Without a constant flow of oxygen-rich blood, the brain and other organs in the body begin to die. After a few minutes, the heart muscle dies completely. This is referred to as sudden cardiac death.
How Is Sudden Cardiac Arrest Diagnosed?
Medical professionals typically diagnose sudden cardiac arrest after the event—either in the hospital or in a post-mortem examination. To bystanders, the clearest indicators are:
- A person’s sudden collapse
- Not breathing or breathing in gasps
- No pulse
If you see someone collapse and stop breathing or breathe in gasps, don’t wait for a diagnosis—act immediately.
How Is Sudden Cardiac Arrest Treated?
The most important treatments for sudden cardiac arrest should be performed by lay rescuers before emergency medical technicians even arrive on the scene:
- Provide immediate, continuous chest compressions to sustain blood flow to the brain and other vital organs (refer to our CPR guide for more information), and send someone to call 9-1-1 and fetch an automated external defibrillator.
- Attach the AED electrode pads to the victim’s bare chest and follow the voice prompts.
- Press the shock button if and when instructed to do so and continue to provide chest compressions.
When EMS personnel arrive, leave the electrode pads attached. These pads record valuable data about the patient’s heart rhythm and shocks provided to help the medical professionals diagnose any underlying conditions and provide the best possible care.
Once the patient is in the hospital, he or she can receive advanced cardiac life support treatments, including medications and surgery, followed by diagnostic procedures like a cardiac MRI and blood tests. If needed, an implantable cardioverter defibrillator might be placed to control dangerous arrhythmias as they arise and prevent another cardiac arrest.
If no AED is available, continue performing chest compressions until emergency services arrive.
Is It Possible to Survive Sudden Cardiac Arrest?
Your chances of surviving sudden cardiac arrest are directly related to the kind of heart arrhythmia you have and how soon chest compressions and defibrillation are performed.
- If you have ventricular fibrillation, receive immediate chest compressions, and are given an electric shock in less than 3 minutes following the witnessed collapse, your chances of survival are around 74%.
- If you have ventricular fibrillation, receive immediate chest compressions, and are given an electric shock more than 3 minutes following the witnessed collapse, your chances of survival are around 49%.
- If you receive no care before emergency technicians arrive, your chances of surviving are around 4%.
As a general rule, a victim’s chances of surviving sudden cardiac arrest drop by 7-10% for each minute without CPR. That’s why it’s so important for SCA victims to be treated immediately.
Risk Factors for Sudden Cardiac Arrest
While SCA sometimes happens without warning, certain people have an increased risk:
- People with heart disease, including:
- Coronary heart disease (also called coronary artery disease), in which blocked coronary arteries restrict blood flow to the heart
- Heart failure, in which the heart pumps blood less effectively
- Hypertrophic cardiomyopathy, which causes a thickened heart muscle
- Cardiomegaly, or an enlarged heart
- People with a personal or family history of heart disease
- People with structural abnormalities in the heart
- People who have suffered a previous heart attack
- People who are obese
- People who lead a sedentary lifestyle
- People with high blood pressure
- People who smoke or abuse drugs
- People who are under a lot of emotional stress
- People who put their bodies under extreme physical stress, such as athletes
People can also suffer cardiac arrest if they have very low blood levels from major blood loss. This is one reason why it’s essential to treat severe bleeding immediately using direct pressure, and if necessary, applying a tourniquet.
How to Reduce Your Risk of Sudden Cardiac Arrest
There are several things you can do to lead a heart-healthy lifestyle and prevent sudden cardiac arrest:
- Eat a fiber-rich diet with plenty of fruits, vegetables, legumes, and oily fish, and minimize processed sugars, refined grains, and vegetable oils
- Get plenty of exercise, including aerobic exercise, strength training, and stretching
- Quit smoking
- Limit your consumption of alcohol and drugs
- Reduce emotional stress by dealing with any known sources of stress, getting out into nature, and practicing prayer, mindfulness, or meditation
Reduce Your Risk of Dying From Cardiac Arrest
If you already have severe coronary artery disease or multiple risk factors, it’s best to be prepared for the worst while working to reduce your risk.
- Learn the warning signs of sudden cardiac arrest.
- Go for a screening if you have a family history of heart disease.
- Encourage your friends and family members to participate in CPR and AED training.
- Get a user-friendly external defibrillator for your home, such as the Philips HeartStart FRx or Defibtech Lifeline, and place it in a clearly signed, accessible location.
- Notify your employer and colleagues that you have risk factors for cardiac arrest so that they can be on alert in case you have a cardiac event.
Remember, sudden cardiac arrest often occurs without warning and is usually fatal within minutes if life-saving measures aren’t taken straight away. Be informed, be prepared, and take steps today to reduce your risk.