Heart Attack

A heart attack, also called a myocardial infarction, occurs when a part of the heart muscle doesn’t get enough blood because a coronary artery has become partially or fully blocked. A heart attack should not be confused with cardiac arrest, when the heart’s electrical system malfunctions and the heart suddenly stops beating.

In the United States, someone has a heart attack every 40 seconds. Every year, about 805,000 Americans have heart attacks, 75% of which are first-time attacks. In early middle age, men have a greater risk of heart attack than women. However, a woman’s risk increases after menopause.


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What are the symptoms of a heart attack?

Recognizing the signs and symptoms of a heart attack can help you get immediate emergency care. Prompt treatment can save your life and limit heart muscle damage.

The most common symptom of a heart attack is chest pain, usually described as crushing, squeezing, pressing, heavy, or occasionally, stabbing or burning. Patients often describe it as more discomfort than pain. The chest discomfort tends to be focused either in the center of the chest or just below the center of the rib cage, and it can spread to the arms, abdomen, lower jaw, or neck.

Other signs can include sweating, nausea, vomiting, shortness of breath, and lightheadedness, sudden weakness, and fatigue.

In both men and women, the most common heart attack symptom is chest discomfort. Women are more likely to also have other associated symptoms, including nausea and shortness of breath. How long heart attack symptoms last varies from person to person.

About half of people who have a heart attack don’t realize it at the time. These so-called “silent heart attacks” are episodes in which symptoms are so subtle that they go unnoticed or are ignored. Some people mistake symptoms as indigestion or muscle pain. Silent heart attacks are usually discovered when a person undergoes an electrocardiogram or echocardiogram for a different reason, and the test shows abnormalities suggestive of heart damage.

What are the risk factors for a heart attack?

A family history of heart disease can raise a person’s heart attack risk. But most heart attacks result from atherosclerosis, a condition in which fatty deposits (plaques) build up on the inside walls of blood vessels. When plaque ruptures, a blood clot forms and blocks blood flow to the heart, triggering a heart attack.  

The risk factors for heart attacks and atherosclerosis are basically the same and include the following:

  • a high level of “bad” low-density lipoprotein (LDL) cholesterol, triglycerides, and/or total cholesterol. Lipoprotein (a) is another type of “bad” cholesterol that leads to heart attacks and atherosclerosis.
  • a low level of “good” high-density lipoprotein (HDL) cholesterol (although it is not necessarily the HDL level that is the cause, but other factors that lead to low HDL levels).
  • high blood pressure (hypertension)
  • diabetes
  • family history of coronary artery disease at an early age
  • smoking
  • obesity
  • lack of exercise

Less commonly, the risk of a heart attack is increased due to other medical conditions such as congenital abnormalities of the coronary arteries or an abnormally increased tendency to form blood clots.

What causes a heart attack?

The heart needs a supply of oxygen-rich blood in order to pump blood to every part of the body. That pipeline is provided by the coronary arteries. No wider than strands of spaghetti, these arteries deliver blood to heart muscle cells.

A heart attack occurs when one of the heart’s coronary arteries becomes blocked or has extremely limited blood flow. 

How are heart attacks treated?

If you think that you, or someone you are with, is having a heart attack, call 911 right away.

The treatment of a heart attack depends on the type of heart attack and how stable the person’s condition is and their immediate risk of death. An electrocardiogram (ECG) is done, and the degree of blockage of the artery is assessed. As soon as possible, the person will receive medicines that help prevent blood clotting in the coronary arteries.

The person will also be given oxygen, pain medication for chest pain, beta-blockers to reduce the heart’s demand for oxygen, and nitroglycerin to help blood flow into heart muscle cells. The person may be started on heparin, a potent clot-busting drug.

Depending on the ECG findings, the doctor may consider reperfusion therapy to quickly restore blood flow to the injured heart muscle and limit permanent damage. In this procedure, a catheter is threaded through a large blood vessel toward the heart. Dye is injected to locate the blockage in the coronary artery. The next step is percutaneous coronary intervention (PCI). A different catheter with a small, deflated balloon is threaded past the blockage, and the balloon is inflated to crush the clot and plaque. Most balloon catheters also have a wire mesh, called a stent, over the balloon. After the balloon is inflated to open the blocked artery, the stent remains in place to keep the artery open.

Reperfusion therapy for some types of heart attacks can also be done with clot-dissolving drugs called thrombolytic agents, such as tissue plasminogen activator (tPA). This drug is used if it would take too long to transfer a patient to a hospital where an angioplasty could be performed.

All other patients receive medical therapy and many also undergo cardiac catheterization to check for blockages. Depending on how many and the types of blockages, treatment can be one or more stents; if several coronary arteries are blocked, and the blockages are widespread, the doctor may opt for bypass surgery (CABG). During this procedure, the surgeon uses a blood vessel from another part of the body to make a new channel so blood can flow around the blocked area of one or more coronary arteries. Sometimes, no intervention beyond increased medical therapy is needed.

Much of the additional treatment for heart attack depends on whether the patient developed any complications. For example, other drugs may be needed to treat dangerous cardiac arrhythmias (abnormal heartbeats), low blood pressure, or congestive heart failure.

While in the hospital, daily medications usually include aspirin, and a second anti-clotting drug for those with stents. In addition, patients receive a beta-blocker, and an angiotensin-converting enzyme (ACE) inhibitor to help the heart work more efficiently. Lowering cholesterol to get the LDL cholesterol below 70 mg/dl is a key goal. This is usually accomplished with a high-dose statin and often a second cholesterol-lowering medication as well. The doctor will also consider prescribing one of the newer diabetes medications (an SGLT2 inhibitor or GLP-1 receptor agonist) to patients with diabetes.  These drugs have been shown to reduce recurrent heart attacks and cardiac events.   

How can I reduce my risk of having a heart attack?

People can reduce their risk of heart attack by adopting the following heart-healthy lifestyle habits. 

Exercise regularly. Exercise helps with many heart attack risk factors. For example, it helps the heart pump more effectively, lowers blood pressure, and helps a person shed excess weight. Guidelines recommend at least 150 minutes per week of moderate-intensity activity or 75 minutes per week of vigorous-intensity activity (or an equal combination of the two).

Adopt a heart-healthy plant-based diet. The Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH) diet emphasize eating heart-healthy foods like fruits, vegetables, whole grains, low-fat dairy products, legumes, nuts, seeds, olive oil, and fish rich in omega-3 fatty acids. Research has shown these diets are associated with lowering blood pressure and cholesterol levels. 

Get enough sleep. Not getting sufficient sleep and struggling with sleep problems like sleep apnea and insomnia raise the risk of heart attack. Most adults need at least seven hours of sleep.  Some tips that may help you sleep better:

  • go to bed and wake up at the same time every day
  • create relaxation rituals like taking a warm bath or listening to calming music before bed
  • control noise
  • dim bright lights
  • avoid caffeine after 2 pm (earlier if you’re particularly sensitive)

Stop smoking. Cigarette smoke contains more than 7,000 chemicals, which can damage your heart and blood vessels. Even if you quit years ago, your heart health can still be at risk. Ask your doctor about options to help you quit, such as behavioral therapy, support groups, nicotine replacement therapy, and medications. 

Reduce stress. Lowering stress can help manage blood pressure, a risk factor for heart attacks. Stress reduction techniques include deep breathing, mindfulness meditation, guided imagery, yoga, and tai chi.

If lifestyle changes do not adequately manage your blood pressure, cholesterol levels, and other heart attack risks factors, your doctor can prescribe medications that may help.

Often after a heart attack, PCI, or CABG, patients are referred to cardiac rehabilitation to learn and begin adopting these new lifestyle changes.

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