A heart attack (medically known as a myocardial infarction) is a deadly medical emergency where your heart muscle begins to die because it isn’t getting enough blood flow. This is usually caused by a blockage in the arteries that supply blood to your heart. If blood flow isn’t restored quickly, a heart attack can cause permanent heart damage and death.
How a blocked artery can cause a heart attack. A myocardial infarction (commonly called a heart attack) is an extremely dangerous condition caused by a lack of blood flow to your heart muscle. The lack of blood flow can occur because of many different factors but is usually related to a blockage in one or more of your heart’s arteries. Without blood flow, the affected heart muscle will begin to die. If blood flow isn’t restored quickly, a heart attack can cause permanent heart damage and death. A heart attack is a life-threatening emergency. If you suspect you or someone you're with is having a heart attack, do not hesitate to call 911 (or your local emergency services phone number). Time is critical in treating a heart attack, and a delay of even a few minutes can result in permanent heart damage or death. How common are heart attacks?New heart attacks happen to about 635,000 people in the U.S. each year. About 300,000 people a year have a second heart attack. About one in seven deaths in the U.S. is due to coronary heart disease, which includes heart attacks. What happens during a heart attack?When a heart attack happens, blood flow to a part of your heart stops or is far below normal, which causes that part of your heart muscle to die. When a part of your heart can’t pump because it’s dying from lack of blood flow, it can disrupt the pumping sequence for the entire heart. That reduces or even stops blood flow to the rest of your body, which can be deadly if it isn’t corrected quickly. What are the symptoms of a heart attack?Heart attacks can have a number of symptoms, some of which are more common than others. The symptoms you have are also influenced by your sex, as with men and women being more likely to have different heart attack symptoms. Common heart attack symptomsSymptoms most often described by people having a heart attack:
Heart attack symptoms in womenMedical research in recent years has shown that women may have the above symptoms, but also have a higher chance of experiencing symptoms different from those listed above.Women are less likely to describe the following:
Women are more likely to describe the following:
Is acute coronary syndrome the same as a heart attack?Acute coronary syndrome is a life-threatening condition that requires emergency medical care and can result in a heart attack. Acute coronary syndrome is a name given to three types of coronary artery disease associated with a sudden rupture of plaque inside the coronary artery:
The location of the blockage, the length of time that blood flow is blocked and the amount of damage that occurs determine the type of acute coronary syndrome.*See the Electrocardiogram description in the Diagnosis & Tests section for an explanation of STEMI and non-STEMI heart attacks.
The vast majority of heart attacks occur because of a blockage in one of the blood vessels that supply your heart. This most often happens because of plaque, a sticky substance that can build up on the insides of your arteries (similar to how pouring grease down your kitchen sink can clog your home plumbing). That buildup is called atherosclerosis. Sometimes, plaque deposits inside the coronary (heart) arteries can break open or rupture, and a blood clot can get stuck where the rupture happened. If the clot blocks the artery, this can deprive the heart muscle of blood and cause a heart attack. Heart attacks are possible without a blockage, but this is rare and only accounts for about 5% of all heart attacks. This kind of heart attack can occur for the following reasons:
Who is most at risk for a heart attack?Several key factors affect your risk of having a heart attack. Unfortunately, some of these risk factors aren't things you can control.
Age and sexYour risk of heart attack increases as you get older, and your sex also influences when your risk of a heart attack starts to increase:
Family historyIf you have a parent or sibling with a history of heart disease or heart attack — especially at a younger age — your risk is even greater. That risk increases with the following:
LifestyleThe lifestyle choices you make can also affect your risk of having a heart attack. The following lifestyle factors increase your risk of heart attack:
Other diseases and health conditionsThe following health conditions can increase your risk of heart attack:
Heart attacks are usually diagnosed in an emergency room setting. A healthcare provider will diagnose a heart attack using the following:
What tests will be done to diagnose this condition?Anyone with heart attack symptoms should undergo a physical examination, including checking pulse, blood oxygen levels, blood pressure, and listening to heart and lung sounds. Other tests used to diagnose heart attack include:
STEMI and non-STEMI heart attacksThe wave of your heart's electrical signal is divided into sections using letters of the alphabet starting at P and ending at U. One particular section of the wave, the ST segment, shows activity in the heart's lower two chambers. Those chambers are the left ventricle and right ventricle. Normally, the ST segment is very flat, but a heart attack that affects the ventricles will often cause the ST segment to be much taller than normal. Healthcare professionals call this kind of heart attack an ST-Elevation Myocardial Infarction, or STEMI. Heart attacks, in general, are broadly split into STEMI and non-STEMI categories, with STEMI heart attacks typically being more severe.
Certain kinds of tests can provide pictures or computer-generated images of the heart. These include:
Treating a heart attack means restoring blood flow to the affected heart muscle as soon as possible. This can happen in a variety of ways, ranging from medication to surgery. It's extremely likely that treatment will use several of the following methods. Supplementary oxygenPeople having trouble breathing or with low blood oxygen levels will often receive supplementary oxygen along with other heart attack treatments. You can breathe the oxygen either through a tube that sits just below your nose or a mask that fits over your nose and mouth. This increases the amount of oxygen circulating in the blood and reduces the strain on your heart. Medications
Percutaneous coronary interventionRestoring circulation to the affected heart muscle is usually done with a procedure called percutaneous coronary intervention. Often called PCI for short, this procedure uses a catheter-based device inserted into a major blood vessel (usually one near your upper thigh). Once the catheter is inserted into the blood vessel through a small incision, the provider threads it up to the blocked artery on your heart. Once it reaches the location of the blockage, the provider will inflate a small balloon on the end of the device to widen the blood vessel and clear the blockage. PCI is a critical tool in restoring blood flow, and the sooner that happens, the better the chance of a good outcome. Hospitals use a metric called “door-to-balloon time” to measure their ability to treat a heart attack. This is the average time it takes for patients to undergo PCI after they first come into the Emergency Room. PCI often includes the placement of a stent at the site of the blockage. Stents are made of metallic mesh and look like tube-shaped scaffolds. They help hold the artery open so another blockage doesn’t happen in the same spot. Some stents are coated with a medication that prevents clotting or tissue growth on the stent itself (either of which could cause another blockage). Patients who have severe blockages of their coronary arteries may undergo coronary artery bypass grafting. This surgery is often called open-heart surgery, bypass surgery or CABG (the acronym is pronounced the same as “cabbage”). CABG involves taking a blood vessel from elsewhere in the body (usually your chest, arm or leg) and using it to construct a detour for blood to use. This reroutes blood around the blocked artery section (or more than one artery; a double bypass goes around two arteries, three is a triple, and so on).
In general, there are many things that you can do that may prevent a heart attack. However, some factors beyond your control — especially your family history — can still lead to a heart attack despite your best efforts. Still, reducing your risk can postpone when you have a heart attack and reduce the severity if you have one. How can I reduce my risk of having a heart attack?Although there are several risk factors that you can’t control, there are many ways you can help yourself and reduce your risk of a heart attack. These include:
Being an active contributor to your health doesn't mean you have to make lifestyle changes all on your own. Ask your primary care provider and other providers on your healthcare team for help. They can provide the information and resources you need, and point you to services from which you might benefit. If you've already had a heart attack, your healthcare provider will recommend a cardiac rehabilitation program. This program's goals are to reduce your chance of a second heart attack. These medically supervised programs provide counseling and focus on the same healthy living goals listed above.
After you've had a heart attack, you're at a higher risk of a similar occurrence. Your healthcare provider will likely recommend follow-up monitoring, testing and care to avoid future heart attacks. Some of these include:
How soon after treatment will I feel better?In general, your heart attack symptoms should decrease as you receive treatment. You will likely have some lingering weakness and fatigue during your hospital stay and for several days after. Your healthcare provider will give you guidance on rest, medications to take, etc. Recovery from the treatments also varies, depending on the method of treatment. The average hospital stay for a heart attack is between four and five days. In general, expect to stay in the hospital for the following length of time:
When can I resume my usual activities?Recovery from a heart attack after you’re released from the hospital depends on the severity of the heart attack, how soon treatment began, methods used and the health conditions you had — if any — before your heart attack. Your healthcare provider can explain the next steps for your recovery and what you can expect. In general, most people can return to work or resume their usual activities anywhere between two weeks to three months after their heart attack.
Complications associated with heart attacks include:
Do women fare better or worse than men after a heart attack?Younger women (pre-menopause) under age 45 have a better outcome than men of a similar age. Scientists believe this is because of estrogen's heart-protective effects. However, after menopause ends the protective benefits of estrogen, women fare worse than men. More specifically:
If you have any symptoms of a heart attack, it’s best to call 911 for multiple reasons:
A note from Cleveland Clinic A blocked artery needs immediate care to prevent permanent heart damage. You may think that if your symptoms are not intense and severe, you’re not having a heart attack. However, it’s best to get your symptoms checked. Calling 911, rather than driving yourself or having someone else drive you, can be even more life-saving than you think. Time saved is heart muscle saved, and that means you have a better chance of a good outcome.
Last reviewed by a Cleveland Clinic medical professional on 08/11/2021. References
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