What elements of a patient's chest pain history are the best predictors for ruling in/out acute myocardial infarction (MI)?
The most useful element for ruling in acute MI is chest pain with radiation to both arms, followed by radiation to the right arm. The most useful elements for ruling out acute MI are pleuritic chest pain, sharp pain, and pain reproduced by palpation. (Strength of Recommendation = A, based on two systematic reviews and one cohort study.)
A systematic review of 64 published studies and one unpublished study (N not reported) reviewed bedside diagnosis of MI in adults presenting to the emergency department with chest pain unrelated to trauma and unexplained by radiography.1 The diagnosis of acute MI was determined by elevated cardiac isoenzymes and electrocardiography (ECG) changes. Factors that most reliably predicted acute MI were pain radiation to the right arm or shoulder (sensitivity = 15% to 41%; specificity = 94% to 95%; positive likelihood ratio [LR+] = 4.7; 95% confidence interval [CI], 1.9 to 12) and radiation to the left arm (sensitivity = 34% to 55%; specificity = 76%; LR+ = 1.8; 95% CI, 1.1 to 2.8). Factors associated with a decreased likelihood included pleuritic pain (sensitivity = 3% to 6%; specificity = 74% to 82%; LR+ = 0.2; 95% CI, 0.2 to 0.3), sharp pain (sensitivity = 8% to 16%; specificity = 59% to 70%; LR+ = 0.3; 95% CI, 0.2 to 0.5), and positional pain (sensitivity = 3% to 11%; specificity = 75% to 87%; LR+ = 0.3; 95% CI, 0.2 to 0.5).
A systematic review of 14 studies (N = 32,241) compared elements of acute chest pain in patients presenting to the emergency department or admitted to the hospital for suspected MI.2 The diagnosis was determined by cardiac enzymes, ECG changes, or discharge diagnosis. Characteristics that most reliably predicted acute MI were pain radiation to both arms (LR+ = 7.1; 95% CI, 3.6 to 14), radiation to the right shoulder (LR+ = 2.9; 95% CI, 1.4 to 6.0), pain in the chest or left arm (LR+ = 2.7; CI not reported), and radiation to the left arm (LR+ = 2.3; 95% CI, 1.7 to 3.1). Factors associated with decreased likelihood included pleuritic chest pain (LR+ = 0.2; 95% CI, 0.2 to 0.3), pain reproduced by palpation (LR+ = 0.2 to 0.4; CI not reported), sharp or stabbing pain (LR+ = 0.3; 95% CI, 0.2 to 0.5), and positional pain (LR+ = 0.3; 95% CI, 0.2 to 0.4).
A prospective observational cohort study (N = 893) examined clinical features of acute MI in patients presenting to the large urban emergency department of a teaching hospital.3 The characteristic that most reliably predicted acute MI was pain radiation to both arms or shoulders (sensitivity = 38.2%; specificity = 90.6%; LR+ = 4.1; 95% CI, 2.5 to 6.5). The factor associated with a decreased likelihood was a tender chest wall (sensitivity = 92%; specificity = 28%; LR+ = 0.3; 95% CI, 0.1 to 1.1).
Copyright Family Physicians Inquiries Network. Used with permission.
Overview
What is a heart attack?
A myocardial infarction (commonly called a heart attack) is an extremely dangerous condition that happens because of 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, 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.
What does a heart attack feel like?
When a heart attack happens, blood flow to a part of your heart stops or is far below normal, which causes injury or death to that part of your heart muscle. 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 your 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. Men and people assigned male at birth (AMAB) are likely to have different heart attack symptoms than women and people assigned female at birth (AFAB).
Symptoms of a heart attack that people describe most often include:
- Chest pain (angina). This can be mild and feel like discomfort or heaviness, or it can be severe and feel like crushing pain. It may start in your chest and spread (or radiate) to other areas like your left arm (or both arms), shoulder, neck, jaw, back or down toward your waist.
- Shortness of breath or trouble breathing.
- Fatigue.
- Trouble sleeping (insomnia).
- Nausea or stomach discomfort. Heart attacks can often be mistaken for indigestion or heartburn.
- Heart palpitations.
- Anxiety or a feeling of “impending doom.”
- Sweating.
- Feeling lightheaded, dizzy or passing out.
Heart attack symptoms in women and people AFAB
Medical research in recent years has shown that women and people AFAB are less likely to have chest pain or discomfort that feels like indigestion. They’re more likely to have shortness of breath, fatigue and insomnia that started before the heart attack. They also have nausea and vomiting or pain in the back, shoulders, neck, arms or abdomen.
What causes a heart attack?
The vast majority of heart attacks occur because of a blockage in one of the blood vessels that supplies 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:
- Coronary artery spasm.
- Rare medical conditions: An example of this would be any disease that causes unusual narrowing of blood vessels.
- Trauma: This includes tears or ruptures in the coronary arteries.
- Obstruction that came from somewhere else in your body: A blood clot or air bubble (embolism) that gets trapped in a coronary artery.
- Electrolyte imbalance.
- Eating disorders: Over time, these can damage your heart and ultimately result in a heart attack.
- Takotsubo or stress cardiomyopathy.
- Anomalous coronary arteries (a congenital heart defect you’re born with where the coronary arteries are in different positions than normal in your body. Compression of these causes a heart attack).
Who is most at risk for a heart attack?
Several key factors affect your risk of having a heart attack. Unfortunately, some of these heart attack risk factors aren’t things you can control.
| Age and sex | Your risk of heart attack increases as you get older. Your sex influences when your risk of a heart attack starts to increase. | Men and people AMAB: The risk of heart attack increases greatly at age 45. Women and people AFAB: The risk of heart attack increases greatly at age 50 or after menopause. |
| Family history of heart disease | If 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 because your genetics are similar to theirs. | Your risk increases if: Your father or a brother received a heart disease diagnosis at age 55 or younger. Your mother or a sister received a heart disease diagnosis at age 65 or younger. |
| Lifestyle | Lifestyle choices you make that aren’t good for your heart can increase your risk of having a heart attack. | These increase your risk of heart attack: Lack of physical activity. A diet high in sodium, sugar and fat. Smoking or tobacco use (including smokeless or chewing tobacco and vaping). Drinking too much alcohol. Drug use (especially in younger people). |
| Certain health conditions or diseases | Some health conditions put stress on your heart. | Having these health conditions can increase your risk of heart attack: Diabetes. Obesity. High blood pressure (hypertension). High cholesterol (hyperlipidemia). History of preeclampsia during pregnancy. Eating disorders (especially in younger people). |
Diagnosis and Tests
How are heart attacks diagnosed?
Healthcare providers usually diagnose heart attacks in an emergency room setting. Anyone with heart attack symptoms should undergo a physical examination, including checking pulse, blood oxygen levels and blood pressure and listening to heart and lung sounds.
A healthcare provider will diagnose a heart attack using the following:
- History and symptoms: The provider will ask you about the symptoms you experienced. They might also ask someone who was with you to describe what happened.
- Blood tests: During a heart attack, the damage to heart muscle cells almost always causes a chemical marker, a cardiac troponin, to appear in your bloodstream. Blood tests that look for that marker are among the most reliable methods to diagnose a heart attack.
- Electrocardiogram (EKG or ECG): This is one of the first tests you get when you come to an ER with heart attack symptoms.
- Echocardiogram: Using ultrasound (high-frequency sound waves), an echocardiogram generates a picture of the inside and outside of your heart.
- Angiogram: This test shows areas with little or no blood flow.
- Heart computed tomography (CT) scan: This creates a highly detailed scan of your heart.
- Heart MRI: This test uses a powerful magnetic field and computer processing to create an image of your heart.
- Nuclear heart scans: Similar to angiography, these scans use a radioactive dye injected into your blood. What sets them apart from an angiogram is that they use computer-enhanced methods like computed tomography (CT) or positron emission tomography (PET) scans.
Management and Treatment
How are heart attacks treated?
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 oxygen
People having trouble breathing or with low blood oxygen levels 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
- Anti-clotting medications: This includes aspirin and other blood-thinning medicines.
- Nitroglycerin: This medicine relieves chest pain and causes blood vessels to widen so blood can pass through more easily.
- Thrombolytic (clot-busting) medications: Providers use these only within the first 12 hours after a heart attack.
- Anti-arrhythmia medications: Heart attacks can often cause malfunctions in your heart’s normal beating rhythm called arrhythmias, which can be life-threatening. Anti-arrhythmia medications can stop or prevent these malfunctions.
- Pain medications: The most common pain medication given during heart attack care is morphine. This can help alleviate chest pain.
Percutaneous coronary intervention
Providers restore circulation to your affected heart muscle with a procedure called percutaneous coronary intervention (PCI). This uses a catheter-based device inserted into a major blood vessel (usually one near your upper thigh or your wrist).
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 people 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 to help hold the artery open so another blockage doesn’t happen in the same spot.
Coronary artery bypass grafting
People 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 using a blood vessel from elsewhere in your body (usually your chest, arm or leg) to construct a detour for blood. This reroutes blood around one or more blocked artery sections and brings blood to your heart muscle.
Prevention
Can I prevent having a heart attack?
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:
- Schedule a checkup: Find a primary care provider and see them at least once a year for a checkup or wellness visit. An annual checkup can catch many of the early warning signs of heart disease, including signs that you can’t feel. These include your blood pressure, blood sugar levels, cholesterol levels and more.
- Quit tobacco products: This includes smokeless tobacco and all vaping products.
- Exercise regularly: Aim for 30 minutes of moderately intense physical activity five days a week.
- Eat a healthy diet: Examples include the Mediterranean or Dash diets. A plant-based diet approach is an excellent alternative.
- Maintain a weight that’s healthy for you: Your primary care provider can advise you on a healthy goal weight and provide you resources and guidance to help you reach that goal.
- Manage your existing health conditions: This includes high cholesterol levels, high blood pressure and diabetes.
- Reduce your stress: Consider techniques such as yoga, deep breathing and meditation.
- Take your medications as prescribed: Don’t just take medications when you remember to or when you have a doctor’s appointment coming up.
- Keep all your medical appointments: Seeing your healthcare providers regularly can help uncover heart-related issues or other medical problems you didn’t know you had. This can also help treat problems sooner rather than later.
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.
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.
Outlook / Prognosis
What can I expect if I have this condition?
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:
- Heart scans: Similar to the methods used to diagnose a heart attack, these can assess the effects of your heart attack and determine if you have permanent heart damage. They can also look for signs of heart and circulatory problems that increase the chance of future heart attacks.
- Stress test: These heart tests and scans that take place while you’re exercising can show potential problems that stand out only when your heart is working harder.
- Cardiac rehabilitation: These programs help you improve your overall health and lifestyle, which can prevent another heart attack.
Additionally, you’ll continue to take medicines — some of the ones you received for immediate treatment of your heart attack — long-term. These include:
- Beta-blockers.
- ACE inhibitors.
- Aspirin and other blood-thinning agents.
How soon after treatment will I feel better?
In general, your heart attack symptoms should decrease as you receive treatment. You’ll 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:
- Medication only: People treated with medication only have an average hospital stay of approximately six days.
- PCI: Recovering from PCI is easier than surgery because it’s a less invasive method for treating a heart attack. The average length of stay for PCI is about four days.
- CABG: Recovery from heart bypass surgery takes longer because it’s a major surgery. The average length of stay for CABG is about seven days.
When can I resume my usual activities?
Recovery from a heart attack after leaving the hospital depends on the severity of the heart attack, how soon treatment began, the 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. Cardiac rehab can help people gradually and safely increase their physical activity back to its prior level.
Living With
What are the complications of a heart attack?
Complications associated with heart attacks include:
- Arrhythmias (abnormal heart rhythms).
- Heart failure.
- Heart valve problems.
- Sudden cardiac arrest.
- Depression andanxiety.
- Mechanical complications of a heart attack, such as a ventricular septal defect or free wall rupture. These are more likely to happen with delayed treatment of a heart attack.
Who fares better after a heart attack?
Younger women (pre-menopause) and people AFAB under age 45 have a better outcome than men and people AMAB 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:
- Women between the ages of 45 and 65 who’ve had a heart attack are more likely to die within a year of the event compared with men of this same age.
- Women over age 65 are more likely to die within weeks of their heart attack than men over age 65.
Frequently Asked Questions
Why should I call 911 if I can drive myself to the hospital (or have someone drive me)?
If you have any symptoms of a heart attack, it’s best to call 911 for multiple reasons:
- First responders can do some of the early testing and treatment for a heart attack on the way to the hospital. This can speed up the overall diagnosis and treatment process.
- If you come into the hospital by ambulance, you usually have more immediate access to care. When you’re having a heart attack, every second matters.
- Heart attacks can cause your heart to beat irregularly or stop entirely, either of which could cause you to pass out. If you’re in an ambulance when that happens, first responders can react immediately to stabilize you. You also won’t have to worry about passing out behind the wheel and causing a crash that could have devastating consequences for yourself or others.
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 1 in 7 deaths in the U.S. is due to coronary heart disease, which includes heart attacks.
A note from Cleveland Clinic
A blocked artery needs immediate care to prevent permanent heart damage. You may think that if your symptoms aren’t 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 a heart muscle saved, and that means you have a better chance of a good outcome.