Sudden Cardiac Arrest vs. Heart Attack: Understanding the Difference


Old woman laying in bed holding her chest

Sudden cardiac arrest and heart attacks are both serious medical emergencies, but it’s important to recognize that they are two distinct conditions.

Understanding the key differences will help you respond appropriately during an emergency.

In this article, we’ll take an in-depth look at both cardiovascular events to help you learn about the differences, how you should respond, and what you can expect afterwards.

Key Differences Between Heart Attacks and Sudden Cardiac Arrest

Sudden cardiac arrest

Heart attack

Development

Occurs when a person’s heart stops pumping blood. Can also develop because of an irregular heart rhythm (arrhythmia).

Occurs when the coronary arteries become blocked, and the blood supply to the heart is cut off.

Onset of symptoms

Sudden, intense, and life-threatening. Warning signs rarely precede the event.

May be sudden or develop gradually over a few minutes or hours. Warning signs typically precede the event.

Emergency response

Immediate CPR and defibrillator use are essential. Immediately dial 911.

Immediately dial 911.

An Overview of Heart Attacks

What is a heart attack?

A heart attack — also known as a myocardial infarction — occurs when the flow of oxygen-rich blood to the heart is severely reduced or cut off completely.

This often happens due to blocked or narrowed arteries that cause blood clots to form. It’s these clots that block the flow of blood to the heart.

If left untreated, the heart will begin to die because of a lack of oxygen, leading to a heart attack.

Symptoms of a heart attack

Common signs and symptoms of a heart attack may include:

  • Chest pain — described as a feeling of pressure, tightness, or squeezing — that lasts for a few minutes

  • Pain or discomfort in the upper body, including one or both arms, the back, shoulders, neck, jaw, and part of the stomach

  • Shortness of breath

  • Nausea or vomiting

  • Feeling lightheaded or dizzy

  • Unexplained fatigue

It’s important to note that heart attack symptoms vary between individuals, especially men and women.

For example, women are more likely to experience back or jaw pain, nausea, heartburn, and flu-like symptoms when a heart attack occurs.

If you experience any of these symptoms, seek immediate emergency medical care. Heart attacks can be fatal if left untreated, so prompt action is essential.

What causes a heart attack?

Heart attacks are typically caused by coronary artery disease (CAD), which involves the blockage and narrowing of the arteries that supply blood to the muscle.

Blockages causing heart attacks are often due to atherosclerosis, which is the accumulation of fatty plaque on the inner walls of the arteries.

This plaque is composed of fat, cholesterol, calcium, and other substances found in the body.

When these plaques rupture, it can cause a blood clot to form that can obstruct the flow of oxygen to the heart and cause a heart attack.

A coronary artery spasm can also cause a heart attack, although this is rare. The artery can spasm due to illicit drug use or it may occur spontaneously without an obvious cause.

Heart attack risk factors

There are several factors that may increase your risk of having a heart attack.

While some of these can be prevented with the right strategies, some risk factors may be unavoidable.

Preventable risk factors

These risk factors can be mitigated with the correct lifestyle changes and taking medication to improve your overall well-being. They include:

  • High blood pressure (hypertension)

  • High cholesterol levels

  • Smoking and tobacco use

  • Diabetes

  • Obesity

  • Living a sedentary lifestyle

  • Following an unhealthy diet high in saturated fats, sodium, and cholesterol

  • Excessive alcohol consumption

  • Stress

Unavoidable risk factors

These risk factors can’t be changed or prevented, and may include:

  • Age: Men over 45 and women over 55 are at a higher risk of experiencing cardiovascular events.

  • Gender: Men are generally more likely to suffer from heart attacks.

  • Family history of heart disease: A genetic predisposition to heart disease can significantly increase your risk of a heart attack.

  • Ethnicity: African Americans may be more likely to experience cardiovascular events like heart attacks.

  • Personal history of heart disease or stroke: Individuals who have had a heart or stroke in the past are more likely to have another one.

Prevention and treatment methods

Depending on your specific risk factors, your doctor may recommend an individual treatment plan to help you manage them.

Generally, preventing a heart attack may involve the following:

  • Getting more regular physical activity

  • Maintaining a healthy weight

  • Following a healthy diet rich in fruits, vegetables, whole grains, and lean proteins

  • Managing your blood pressure and cholesterol

  • Getting regular checkups for conditions like diabetes

  • Minimizing your stress and practicing stress management techniques

  • Limiting alcohol

  • Quitting smoking

If you’ve already suffered a heart attack, there are various steps your doctor may recommend to help you recover and get back to living a normal life. This may include:

  • Using various medications to prevent or dissolve blood clots, such as thrombolytic and antiplatelet agents

  • Taking pain relievers, beta blockers, ACE inhibitors, or statins

  • Undergoing surgical procedures to open or bypass blocked arteries

  • Following a cardiac rehabilitation program designed to improve your heart health

While these treatment options may not guarantee the prevention of a second heart attack, they can substantially lower your risk of a recurrence.

An Overview of Sudden Cardiac Arrest

What is sudden cardiac arrest?

Sudden cardiac arrest (SCA) is a medical emergency that occurs when the heart suddenly and unexpectedly stops beating.

It differs from a heart attack, which is caused by a blockage in the arteries that prevents blood flow to the muscle.

SCA is primarily an electrical issue in the heart that disrupts its pumping action and stops blood flow to the body.

What are the symptoms of sudden cardiac arrest?

The onset of SCA is usually very rapid, and symptoms are immediate and severe. They may include:

  • Sudden collapse due to loss of consciousness

  • No detectable pulse

  • Unresponsiveness

  • No signs of movement

In rare cases, there might be other symptoms that develop just before a person collapses, including:

  • Chest discomfort

  • Weakness

  • Rapid or irregular heartbeats

  • Feeling faint

If you or someone around you seems to be experiencing SCA symptoms, call 911 immediately.

This condition can be fatal if prompt action isn’t taken to access professional medical care. You may also administer hands-only CPR if you are an untrained bystander.

Key Point: How Do You Perform Hands-Only CPR?

This lifesaving technique involves performing chest compression without mouth-to-mouth breathing. It’s administered as follows:

  • Position the heel of your one hand in the center of the person’s chest, on the lower half of the breastbone. Place your other hand on top and interlock your fingers.

  • Position your body and shoulders directly over your hands. Keep your arms straight.

  • Press down hard and fast, compressing the chest at least two inches deep. Let the chest rise completely before pressing down again.

  • Aim for a compression rate of 100 to 120 compressions per minute. A widely recommended medical guideline suggests compressing to the rhythm of the Bee Gees' song "Stayin' Alive," which has a tempo of 103 beats per minute.

  • Keep performing chest compressions without interruption until emergency help arrives or a defibrillator is ready to use.

If you’re not trained in CPR, this hands-only approach is still better than doing nothing and can significantly increase a person’s chances of survival.

Why does sudden cardiac arrest happen?

There are various causes of SCA, which may include any of the following:

  • Ventricular fibrillation (VF)

  • Structural heart disease

  • Heart attack

  • Severe physical stress

  • Electrolyte imbalances

  • Substance use, including medications, drugs, and alcohol

  • Other factors like a severe blow to the chest, extreme emotional stress, or underlying conditions like valve disease

It’s important to note that cardiac arrest can also occur without warning, even if you haven’t been diagnosed or you don’t have a history of heart disease.

Risk factors for sudden cardiac arrest

Similar to heart attacks, SCA risk factors can also be divided into preventable and unavoidable groups.

Preventable risk factors

These risk factors can be managed with medication and by implementing various lifestyle changes aimed at reducing the likelihood of suffering cardiac events.

Preventable factors may include:

  • Coronary artery disease (CAD)

  • History of a heart attack or heart failure, especially if it was recent

  • Cardiomyopathy

  • Poorly controlled heart disease

  • Electrolyte imbalances

  • Recreational drugs use

  • Chronic kidney disease

  • Obesity

  • Diabetes

  • Sleep apnea

Unavoidable risk factors

Unavoidable risk factors are those that can’t be prevented and may include:

  • Age: The risk of SCA increases with age, particularly in men over 45 and women over 55.

  • Gender: Men are usually at a higher risk of SCA compared to women.

  • Family history: A family history of CAD, heart attacks, or SCA elevates the risk.

  • Genetic factors: Certain inherited or genetic conditions — like long QT syndrome or hypertrophic cardiomyopathy — increase your risk of SCA.

  • Ethnicity: African Americans may have a higher risk of SCA, possibly due to higher rates of high blood pressure and heart disease in this group.

Can sudden cardiac arrest be prevented or treated?

Preventing and treating SCA involves a combination of lifestyle changes and medical intervention to help you lead a normal life.

Common preventative strategies may include:

  • Managing heart disease through regular monitoring and treatment

  • Following a heart-healthy diet rich in fruits, vegetables, whole grains, and lean proteins

  • Increasing physical activity

  • Avoiding smoking

  • Limiting alcoholic beverages

  • Managing high blood pressure and cholesterol

  • Maintaining a healthy weight

  • Getting regular checkups

If you’ve already suffered from SCA, your doctor may recommend various long-term treatment options to reduce your risk of recurrent events. These options typically include:

  • Undergoing surgery for an implantable cardioverter-defibrillator (ICD)

  • Using medications such as beta blockers, ACE inhibitors, or anti-arrhythmics

  • Following a cardiac rehabilitation program aimed at improving your overall heart health

Depending on your specific circumstances, your doctor will also recommend lifestyle changes to help you manage your condition more effectively.

Where Can You Learn More About Managing Cardiovascular Conditions?

If you’re concerned about your symptoms or want to know more about cardiovascular conditions, LifeMD is here to help.

LifeMD can connect you to a team of medical professionals who can provide information and guidance on managing your condition while avoiding further complications.

Make an appointment today to get started.

Jennifer McMillan, APRN, FNP-BC

Jennifer is a board-certified, multistate licensed Nurse Practitioner with over 25 years experience in healthcare. She specializes in Women and Men’s Health, Psychiatry, and Urgent Care. She enjoys including her patients in the decision-making process regarding their care to help them reach and maintain their health goals. In her free time, Jennifer enjoys doing volunteer work at the American Heart Association.

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This article is intended for informational purposes only and should not be considered medical advice. Consult a healthcare professional or call a doctor in the case of a medical emergency.

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