When it comes to your heart, every second counts — but not every emergency is the same.
Many people think a heart attack and cardiac arrest are the same thing. A heart attack can sometimes lead to sudden cardiac arrest (SCA), but they are not the same condition. Knowing the difference could help you act fast when it matters most.
What is a heart attack?
A heart attack, also known as a myocardial infarction, is a serious medical emergency that happens when blood flow to part of the heart is blocked. This blockage is often caused by plaque buildup, blood clots or narrowed arteries, and it stops oxygen-rich blood from reaching the heart muscle. During a heart attack, your heart usually keeps beating, but the lack of oxygen can cause dangerous irregular rhythms.
Heart Attack Symptoms
Recognizing the signs of a heart attack can save your life, or even someone else’s. Not every heart attack looks the same. Early warning signs of a heart attack can be mild and build gradually, or they can strike suddenly and severely.
Common heart attack symptoms include:
- Chest pain or pressure (often described as squeezing or heaviness)
- Shortness of breath
- Nausea or vomiting
- Sweating
- Pain that radiates to the arm, jaw or back
“A heart attack can present differently for each person,” said Amit Mehrotra, MD, cardiac electrophysiologist, OSF HealthCare. “Paying attention to your body and acting fast is crucial.”
How is a heart attack treated?
Heart attack treatment is always a medical emergency. Doctors may perform an angioplasty, which uses a stent to reopen the blocked artery. In addition, quick-acting medications can help restore blood flow and protect the heart muscle.
What is the survival rate for a heart attack?
The heart attack survival rate depends on how quickly someone receives treatment. The faster blood flow is restored, the more heart muscle can be saved. That’s why experts often use the phrase, “Time is muscle.”
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What is cardiac arrest?
Sudden cardiac arrest is a life-threatening emergency that happens when the heart’s electrical system malfunctions. Instead of pumping blood normally, the heart suddenly stops beating or begins to quiver. When this happens, blood flow to the brain and body stops within seconds.
Causes of Cardiac Arrest
The causes of cardiac arrest are often linked to electrical problems in the heart, such as:
- Heart rhythm problems: The heart suddenly beats abnormally (ventricular fibrillation), stopping it from pumping blood
- Heart attack: A blocked artery cuts off blood flow to the heart muscle, leading to electrical failure
- Severe trauma, drowning, drug overdose or major blood loss that stops the heart suddenly
Cardiac Arrest Symptoms
Unlike a heart attack, the onset of cardiac arrest is immediate, with symptoms appearing instantly and without warning. Signs of cardiac arrest include:
- Sudden collapse
- No breathing
- No pulse
“A person may be fine one moment and unconscious the next, which is why quick action is critical,” said Dr. Mehrotra.
How is cardiac arrest treated?
Cardiac arrest is a medical emergency that requires immediate action. Treatment involves cardiopulmonary resuscitation (CPR) to keep blood flowing and the use of an automated external defibrillator (AED) to restore a normal heart rhythm.
AEDs are easy-to-use devices that allow bystanders to assist during a cardiac emergency until medical help arrives. Many states require them in public places like schools, gyms, malls and airports.
What is the survival rate for cardiac arrest?
The cardiac arrest survival rate is low without help. When bystanders act fast by performing CPR immediately and using an AED to defibrillate the heart, it can dramatically increase your chance of survival.
What to Do in an Emergency
Knowing how to act fast can save a life. Here’s what to do if someone shows signs of a heart attack or goes into cardiac arrest:
If someone is having a heart attack:
- Call 9-1-1 immediately.
- Have the person sit or rest in a comfortable position.
- Take prescribed medication, like nitroglycerin, if available.
- Chew one adult aspirin (if safe and approved by their doctor).
If someone is in cardiac arrest
- Call 9-1-1 immediately.
- Start CPR right away. Hands-only CPR is effective, even if you’re untrained.
- Use an AED if one is available to help restart the heart.
“Every second matters,” Dr. Mehrotra stressed. “Quick action from bystanders often determines whether someone survives or suffers lasting damage.”
Heart Emergency Prevention and Awareness
You can’t always control when a heart emergency happens, but there are steps you can take to lower your risk.
You can lower your heart attack risk by:
- Staying active
- Eating a heart-healthy diet, including fruits, vegetables, whole grains and lean proteins
- Quitting smoking
- Managing blood pressure and cholesterol
You can lower your risk for sudden cardiac arrest by:
- Managing existing heart conditions, including heart disease or arrhythmias
- Keeping up with regular office visits with your primary care provider or cardiologist
- Knowing your family history
You can also help manage heart emergencies for other people by learning how to perform CPR and how to use an AED.
“Being proactive gives you the best chance of protecting yourself and loved ones,” said Dr. Mehrotra.
Last Updated: November 6, 2025