When comparing cardiac arrest vs heart attack, it’s important to note that, while the two terms are often used interchangeably, they represent different health conditions with very different causes, symptoms, and treatment requirements.
The main difference between a heart attack and cardiac arrest is that a heart attack results from poor circulation while sudden cardiac arrest (SCA) results from an electrical malfunction. A heart attack is generally triggered by some form of blockage while cardiac arrest causes the heart to stop beating without warning due to a misfire.
These events also vary in their prognoses. Of the approximately one million heart attacks occurring every year in the U.S., only 14% are fatal. Of the estimated 356,000 cardiac arrests, nearly 90% are fatal. There are other important differences as well, which become more apparent when we compare the causes, symptoms, and treatments.
Cardiac Arrest
Sudden cardiac arrest is the nation’s leading cause of death. The American Heart Association states that heart disease is the leading cause of death, but both statements are true. Cardiac arrest falls under the umbrella of heart disease and kills more people than heart attacks.
What is Cardiac Arrest?
Sudden cardiac arrest is the result of an electrical malfunction in the heart, which disrupts the heart’s natural pumping activity and can render it unable to pump blood throughout the body.
Cardiac arrest is often fatal because the disruption inhibits all blood flow from the heart to the other organs. The critical difference between a cardiac arrest vs a heart attack is that the heart shuts down following cardiac arrest (whereas after a heart attack it can still pump). Without oxygen-rich blood to the brain and other organs, those organs will fail within minutes, resulting in death.
What are the Symptoms of Cardiac Arrest?
A heart attack may provide days’ or even weeks’ worth of warning, but cardiac arrest comes on without prior indication in approximately 50% of cases. This is another significant difference between cardiac arrest and heart attack.
With that said, a heart attack can often lead to sudden cardiac arrest if the lack of circulation to the affected portion of the heart continues without treatment, resulting in the electrical malfunction and associated loss of effective heart pumping.
This lack of an effective heartbeat, also known as sudden cardiac arrest, is considered clinical death, although resuscitation is possible with the rapid use of a defibrillator in combination with effective CPR. When symptoms are present prior to a sudden cardiac arrest, they are often similar to those of a heart attack, including:
- Chest pain
- Dizziness
- Shortness of breath
- Fatigue
When SCA sets in, the victim loses consciousness and stops breathing. Because the heart has stopped, the victim will have no pulse. Action must be taken immediately, as the victim’s chance of survival decreases by about 10% with each passing minute. Normal heart function must be restored within about 10 minutes, preferably less.
What Causes Cardiac Arrest?
The primary cause of cardiac arrest is an abnormal hearth rhythm. Common examples of these abnormalities are ventricular fibrillation and pulseless ventricular tachycardia.
Ventricular fibrillation is an abnormal heartbeat originating from the lower chambers of the heart. It leads to erratic electrical impulses that cause the heart’s chambers to twitch rather than effectively pump blood.
Ventricular tachycardia occurs when the electrical activity is targeting the lower chambers of the heart and causing them to beat at an elevated rate—usually over 100 beats per minute. Pulseless ventricular tachycardia happens when the electrical rate transmitting to the ventricles is too rapid for the ventricles to respond. This lack of response means that no blood is circulated to the body.
Other, more immediate causes of SCA include:
- Electrocution
- Drowning
- Choking
- Hypothermia
- Pacemaker failure
A sudden drop in blood pressure can also disrupt heart rhythms and lead to SCA.
Who Is Most at Risk for Sudden Cardiac Arrest?
As with heart attacks, SCA can be triggered by coronary heart disease. In fact, a heart attack can immediately trigger cardiac arrest. This is yet another reason why there’s so much confusion between the two conditions. Anyone living with heart disease is at an elevated risk for both conditions, and many of the same risk factors—like smoking, high blood pressure, and obesity—apply.
People with certain heart abnormalities are also at an elevated risk. These abnormalities include an enlarged heart, irregular heart valves, and electrical impulse problems. In these cases, a doctor may recommend a defibrillation device like an implantable cardioverter defibrillator (ICD) to combat the risk of cardiac arrest.
Many sufferers are people who have previously experienced a heart attack or cardiac arrest. Men are more likely to experience this type of event. Although men over 45 and women over 55 are the most common victims, cardiac arrest can occur at any age. More than 2,000 children and 5,000 adolescents experience SCA every year.
How to Prevent Sudden Cardiac Arrest
Since heart attacks and cardiac arrests both stem from heart disease, and since so many cardiac arrests are triggered by heart attacks, the most important prevention measure you can take is to live a heart-healthy lifestyle. That means:
- Maintaining a healthy weight
- Eating the right foods (reduce sodium, sugar, and saturated and trans fats)
- Avoiding risky lifestyle factors like smoking and excess alcohol consumption.
- Exercising daily
If you have already had a heart attack, talk to your doctor about your risk for sudden cardiac arrest. They may prescribe a type of medication known as a beta-blocker to reduce your risk of SCA. If you have previously experienced cardiac arrest or if you have elevated risk factors like abnormal heart valves, they may recommend an ICD or wearable defibrillator to help prevent a recurrence.
Most importantly, be consistent about getting annual check-ups with your doctor. They can spot the risk factors—like abnormal heart rhythms, prediabetes, and high cholesterol—early on and provide you with a preventative plan of action.
What to Do in the Event of a Cardiac Arrest
Almost all instances of SCA are reversible if treated immediately. If you see someone who is experiencing cardiac arrest, call 911 immediately and express the urgent need for emergency medical services.
There are two steps required to restore the victim’s heart rhythm and save their life:
- Cardiopulmonary resuscitation (CPR)
- Heart defibrillation
If at all possible, get your hands on an automatic external defibrillator. Public environments like offices, hotels, or gyms typically have AED devices for cases of emergency. One person should immediately start administering CPR while another person retrieves the defibrillator.
To perform CPR, push down firmly on the victim’s chest at a rate of 100 to 120 pushes per minute. After each push, wait for the chest to return to its normal position. One common trick is to time your pushes to the beat of the song “Stayin’ Alive.” This will help you to maintain the optimal pace. If no AED is available, continue doing this until emergency services arrive.
If an AED is available, turn it on and follow the audible instructions to provide the necessary heart shocks and restore the rhythm. Contemporary AEDs are designed for ease of use, providing voice—and in some cases visual—instructions to guide you through the entire process.
You’ll have two pads that should be applied to the chest; use the image on the back of each pad as a placement guide. Then activate the AED to administer shock. If done quickly and correctly, there is a high likelihood that the victim’s life will be saved.
Heart Attack
A heart attack is a medical emergency that takes place when a blood clot blocks blood flow to the heart. Without blood, tissue loses oxygen and dies.
Heart attacks are more common than cardiac arrests, but less likely to be fatal. In the U.S. alone, a person suffers a heart attack every 40 seconds. About 68% are first-time heart attacks, and 32% are recurrent.
Like any muscle, the heart needs an oxygen-rich blood supply. Coronary arteries deliver blood to the heart, which then pumps the blood to the brain, lungs, and other organs. If one of those coronary arteries is blocked, the blood is unable to reach the heart muscle. As a result, the heart is unable to function properly and can begin to die without quick treatment. The danger increases for as long as the heart is without a steady blood supply.
Symptoms of a Heart Attack
If a person suffers a heart attack, their heart will usually continue beating. This is one way in which a heart attack differs from sudden cardiac arrest. Whereas cardiac arrest happens all at once and usually results in a stopped heart with no effective heartbeat or circulation, and a resulting loss of consciousness, a heart attack usually emerges gradually and occurs without the victim losing consciousness.
In the hours or days leading up to a heart attack, the victim may experience symptoms like:
- Chest pain
- Shortness of breath
- Coughing
- Dizziness
- Sweating
- Jaw pain
- Heart palpitations
Chest pain is often the most obvious symptom, characterized by tightness in the center of the chest. It’s important to note, though, that not everyone experiences this symptom before a heart attack.
Heart attack symptoms can differ between men and women. While chest pain is common in both women and men, symptoms like coughing, sweating, nausea, and jaw pain are more common among women.
During a heart attack, the person may experience extreme pressure or pain that starts in the center of the chest and expands to the back, neck, arms, and other parts of the body. Some people have described it as feeling like an elephant is sitting on their chest. They may also experience shortness of breath.
Heart Attack Causes
As previously noted, heart attacks are triggered by blockages within the coronary arteries. This type of blockage is known as coronary heart disease (CHD).
Fatty deposits accumulate and harden along the inner-walls of the artery, narrowing the space through which blood travels and inhibiting the flow. This type of buildup is referred to as atherosclerosis. Without a steady supply of oxygen-rich blood, the heart loses its ability to provide blood to the rest of the body.
Who Is Most at Risk for a Heart Attack?
Whereas cardiac arrest can sometimes impact otherwise healthy people, heart attacks are almost always the result of lifestyle factors. There are exceptions, such as if the sufferer has a genetic condition like hyperlipidemia or congenital heart disease. In most cases, though, the risks are connected to lifestyle.
Habits like smoking, poor diet, and lack of exercise can all lead to conditions that increase the likelihood of heart attack. These conditions include obesity, high blood pressure, hypertension, diabetes, and ultimately heart disease. Even a slim person with a healthy weight can develop clogged arteries and heart disease as a result of poor diet.
Even when accounting for the risk factors, certain people are statistically more likely than others to have a heart attack. Men, for example, are more prone than women, possibly because estrogen plays a role in preventing heart disease. However, women with diabetes are more prone to heart disease than men with diabetes. African Americans are also at an elevated risk.
How to Prevent a Heart Attack
Though heart attacks are more common than cardiac arrest, they’re also easier to prevent with certain lifestyle changes. A heart-healthy diet is the best place to start. Mediterranean diets and vegan diets are known for being especially heart-healthy, but the key is to minimize saturated and trans fats, emphasize vegetables and fruits, and keep sodium at a minimum.
The American Heart Association recommends no more than 2,300 milligrams of sodium a day, with a preferred cap of 1,500 milligrams. Saturated fat should be limited to no more than 5-6% of daily calories consumed. In terms of sugar intake, the AHA recommends no more than 150 calories’ worth of sugar per day for men, and no more than 100 calories per day for women.
In addition, every adult should strive for at least 30 minutes of activity every day and avoid harmful habits like smoking and excess alcohol consumption. If you have a condition that exacerbates your heart attack risk, such as diabetes, take steps to keep it under control. Finally, remember that stress can be a trigger for heart attacks. This is an often-overlooked risk factor, but it’s very important to keep stress levels under control. Finally, try to get at least 7 to 8 hours of sleep per night.
Your doctor can be your biggest ally for heart attack prevention. Make sure to have your blood pressure, cholesterol, and triglyceride levels checked at least once a year. These are among the biggest risk factors for heart disease, and your doctor can provide medications or guide any lifestyle changes if needed. Finally, strive to maintain a healthy weight. You can use a BMI calculator to estimate your ideal weight range.
What to Do in the Event of a Heart Attack
If you sense that you’re having a heart attack or you see someone having a heart attack, call 911 or emergency services right away. Ask for emergency medical services, as they can start administering treatment as soon as they arrive.
You may be tempted to drive to the hospital, but it’s better to let emergency services take care of it. They understand the proper protocols and sufferers who arrive by ambulance to the emergency room typically receive treatment faster.
Prevention and Prompt Proper Treatment Save Lives
Though the mechanisms are different, the underlying causes and risk factors share a lot of similarities. Prevention—at least those aspects of prevention within your control—is all about maintaining the kinds of healthy lifestyle habits you learned as a child: eat well, exercise, don’t smoke, and avoid excess alcohol.
The biggest difference is in how to save lives. For instance, using a defibrillator on a conscious heart attack victim is not recommended, but for sudden cardiac arrest, rapid electrical treatment delivered by a defibrillator is the only effective treatment. Since so many more people die from cardiac arrest than a heart attack, AED devices should be available in all public gathering places and in the homes of high-risk individuals and caretakers.
Finally, remember to be good to your heart. Heart disease kills more Americans than any other cause or condition, but you don’t have to become a statistic. Even if some of the damage is already done, you can take steps to improve your heart health and live your longest, fullest life.
