People tend to confuse the terms heart attack and cardiac arrest, and it’s easy to see why. Both come on suddenly, and both can be fatal. They can also sometimes trigger similar symptoms, like chest pain, shortness of breath and fatigue.
But these cardiac events are distinct from each other and have very different causes. A heart attack is often referred to as a “plumbing” problem, because blood flow to the heart is interrupted, causing heart tissue to die. Cardiac arrest, on the other hand, is most commonly an electrical malfunction inside the heart, triggering an irregular heartbeat that can cause the heart to stop beating.
For National Sudden Cardiac Arrest Awareness Month, learn more about the differences between a heart attack and cardiac arrest, why knowing the risk factors of each can help lead to early intervention, plus the innovations Johnson & Johnson is working on to help improve the lives of people with heart disease.
What is a heart attack?
A heart attack happens when the supply of blood to the heart is severely restricted or totally cut off, explains Rachel Keever, M.D., Medical Executive, Health Systems Integration at Johnson & Johnson Innovative Medicine’s Cardiovascular therapeutic area in the U.S. Though it’s rare for the heart to stop beating during a heart attack, the lack of blood flow leaves heart tissue damaged, and it begins to die. A person’s life is at risk unless there’s immediate medical intervention.
The leading cause of a heart attack is coronary heart disease, a condition whereby the heart’s major blood vessels become clogged with plaque—which is made up of fat deposits and other substances. When the plaque grows to a point where it impedes normal blood flow, it results in a heart attack.
Coronary heart disease is brought on by many risk factors that tend to build over time, says Dr. Keever. These include preexisting medical conditions contributing to plaque buildup like diabetes, high blood pressure, high cholesterol and obesity. Smoking, which can cause arteries to narrow, and a family history of coronary heart disease also increase a person’s odds, she says.
No one can change their genes, but there are ways to reduce heart attack risk—like quitting smoking, exercising regularly and limiting ultra-processed foods and saturated fats (both of which are linked to plaque buildup). Dr. Keever says it’s also vital to manage diabetes, high blood pressure and other medical conditions with the help of a healthcare professional.
Warning signs of a heart attack include chest pressure or pain, lightheadedness, nausea, vomiting, shortness of breath and discomfort or pain in the jaw, neck or arms. These signs can come on slowly and mimic other conditions, which is why Dr. Keever urges patients to call 911 even if they’re not sure it’s a heart attack, since time is of the essence.
ER doctors typically diagnose a heart attack via an electrocardiogram; they’ll confirm the diagnosis by ordering other tests including a blood test, chest X-ray and echocardiogram. Medication and surgery, such as a bypass or stent placement, are common treatments that, if administered in time, can help a patient recover completely.
What is cardiac arrest?
Cardiac arrest typically happens when an electrical malfunction in the heart causes the heart to stop effectively pumping. As a result, the heart no longer delivers blood to the brain and other organs, says Dr. Keever. Without normal blood flow to the brain and vital organs, cardiac arrest can ultimately be fatal.
Several factors may cause the heart to suddenly stop beating, says Dr. Keever. A heart attack can sometimes lead to an erratic heartbeat and in turn bring on cardiac arrest. Some people are born with a heart problem that can result in a condition known as arrhythmia, which triggers an abnormal heartbeat. One type of arrhythmia, atrial fibrillation (AFib), is the most common cause of an abnormal heartbeat and a risk factor for cardiac arrest.
Heart palpitations and a racing heart can be signs of an arrhythmia, as can fatigue, shortness of breath and anxiety. But often, people don’t know they have these conditions or that they’re at risk for sudden cardiac arrest until it happens.
A noncardiac health issue can also cause cardiac arrest. A pulmonary embolism (PE), for example, has been estimated to account for 4 to 10% of cardiac arrest cases. A pulmonary embolism is a blockage in the lungs from a blood clot that has traveled through the bloodstream from another part of the body. The clot can block the normal flow of blood and put additional strain on the heart, after which heartbeat ceases. PE is reportedly responsible for 2 to 9% of all out-of-hospital and 5 to 6% of all in-hospital cardiac arrests. But these figures are likely an underestimate, as PE is significantly underdiagnosed in clinical practice.
“Sudden cardiac arrest is a little less predictable” than a heart attack, says Dr. Keever, so knowing your family history is crucial. Anyone who’s had family members die suddenly of a heart problem should talk to their doctor, who might recommend a heart test like an electrocardiogram. Some people have fatigue, chest pain, dizziness or shortness of breath while doing an activity leading up to a cardiac arrest, Dr. Keever says, so recognizing these potential warning signs is important.
Most people who experience cardiac arrest die suddenly. Survival usually depends on getting immediate treatment with CPR and an automated external defibrillator. For patients who go into cardiac arrest due to PE, additional potential treatments include administering specific clot-busting medication (thrombolytic drugs such as tPA) or even clot removal surgery (thrombectomy).
Treating cardiovascular disease to save lives
Johnson & Johnson has long focused on developing technology that prevents or treats heart conditions like a heart attack or cardiac arrest. “We’re determined to improve the outlook and empower those living with complex cardiovascular disease to live fuller, more vibrant lives,” says Dr. Keever.
Earlier this year, the company showcased clinical and real-world evidence from its cardiovascular portfolio at the American College of Cardiology 73rd Annual Scientific Session & Expo in Atlanta. This includes a blood thinner medication that’s used to treat coronary artery disease, as well as a clinical trial of a heart pump that’s been shown to improve survival rates for heart attack patients.
Johnson & Johnson has developed medical technology to treat some arrhythmias. One treatment is cardiac (or catheter) ablation, which involves inserting a catheter into the heart and using radiofrequency or pulsed field energy to create scars that block abnormal electrical impulses and restore a regular heartbeat. These advancements are helping doctors treat AFib quickly and effectively.
“Cardiovascular medicine moves very quickly,” says Dr. Keever, emphasizing Johnson & Johnson’s dedication to innovation in heart disease. “To improve both the quantity and quality of human life is part of Our Credo-based commitment to continue our impact.”
