Acute coronary syndrome

This is a range of conditions that cause sudden low blood flow to the heart. An example is a heart attack. Know the symptoms, causes and treatment.

Update Date: 26.04.2025

Overview
Symptoms
Causes
Risk factors
Diagnosis
Treatment
Lifestyle and home remedies
Preparing for an appointment
Overview
Symptoms
Causes
Risk factors
Diagnosis
Treatment
Lifestyle and home remedies
Preparing for an appointment

Overview

Acute coronary syndrome is a term that describes a range of conditions related to sudden reduced blood flow to the heart. These conditions include a heart attack and unstable angina, a type of chest pain.

When blood flow to the heart is reduced, the heart muscle doesn't get enough oxygen. If heart tissue cells die or are damaged, a heart attack happens. A heart attack also is known as a myocardial infarction.

Unstable angina occurs when blood flow to the heart decreases. It's not severe enough to cause heart tissue cells to die or a heart attack. But the reduced blood flow may increase your risk of a heart attack.

Acute coronary syndrome often causes severe chest pain or discomfort. It is a medical emergency that needs a diagnosis and care right away. The goals of treatment are to improve blood flow and treat and prevent complications.

Heart attack

A heart attack occurs when an artery that sends blood and oxygen to the heart is blocked. A buildup of fats, cholesterol and other substances can make arteries narrow, blocking blood flow. This buildup is called plaque. If plaque bursts, a blood clot may form. The clot can lead to a heart attack. During a heart attack, a lack of blood flow causes the tissue in the heart muscle to die.

Symptoms

The symptoms of acute coronary syndrome usually start suddenly. They include:

  • Chest pain or discomfort. It may feel like aching, pressure, tightness or burning. Chest pain also is called angina.
  • Pain that starts in the chest and spreads to other parts of the body. These areas include the shoulders, arms, upper belly area, back, neck or jaw.
  • Nausea or vomiting.
  • Pain or burning in the upper belly, called indigestion.
  • Shortness of breath, also called dyspnea.
  • Sudden, heavy sweating.
  • Racing heartbeat.
  • Feeling lightheaded or dizzy.
  • Fainting.
  • Unusual fatigue.

Chest pain or discomfort is the most common symptom of acute coronary syndrome. But symptoms may vary a lot depending on age, sex assigned at birth and other medical conditions. Women, older adults and people with diabetes are more likely to have symptoms without chest pain or discomfort.

When to see a doctor

Acute coronary syndrome is a medical emergency. Chest pain or discomfort can be a symptom of many life-threatening conditions. Get emergency help right away for a diagnosis and appropriate care. Do not drive yourself to the hospital.

Causes

Acute coronary syndrome usually is caused by a buildup of fatty deposits in and on the walls of the heart's arteries. The fatty deposits also are called plaque. When a fatty deposit breaks open, a blood clot can form. This clot blocks blood flow to the heart. The heart muscle doesn't get enough oxygen.

The lack of oxygen can cause cells in the heart muscle to die. The damage can lead to a heart attack. When acute coronary syndrome doesn't cause heart muscle cells to die, it is called unstable angina.

Risk factors

The risk factors for acute coronary syndrome are the same as those for other types of heart disease. Risk factors include:

  • Older age.
  • High blood pressure.
  • High blood cholesterol.
  • Smoking or tobacco use.
  • Not enough physical activity.
  • An unhealthy diet.
  • Obesity or overweight.
  • Diabetes.
  • Personal or family history of chest pain called angina, heart attacks or stroke.
  • History of high blood pressure, preeclampsia or diabetes during pregnancy.
  • Early menopause.
  • COVID-19 infection.

Diagnosis

Acute coronary syndrome is an emergency. It's usually diagnosed at a hospital. The healthcare team runs tests to check the heart and determine the cause of symptoms. Some tests may be done while the healthcare team asks you questions about your symptoms or medical history.

Tests

Tests for acute coronary syndrome may include:

  • Electrocardiogram. This quick test, also called an ECG or EKG, shows how the heart is beating. Sticky patches with sensors on them attach to the chest and sometimes to the arms or legs. Changes in the heartbeat may mean the heart is not working as it should. Your healthcare professional can look for patterns in the heartbeat to find the general location of any blockages.
  • Blood tests. Some heart proteins slowly leak into the blood after heart damage from a heart attack. Blood tests can be done to check for these proteins.

Your healthcare team looks at your symptoms and test results to diagnose acute coronary syndrome. This information also can help classify your condition as a heart attack or unstable angina.

Other tests may be done to rule out other possible causes of symptoms. The tests also may help determine treatment.

  • Coronary angiogram. This test looks for blockages in the heart arteries. A doctor places a thin, flexible tube called a catheter into a blood vessel, usually in the groin or wrist. It's guided to the heart. Dye flows through the tube to arteries in the heart. The dye helps the arteries show up more clearly on images taken during the test. Some heart treatments can be done during this test.
  • Echocardiogram. Sound waves create pictures of the beating heart. This test shows how blood flows through the heart and heart valves. An echocardiogram can show whether the heart is pumping as it should.
  • Myocardial perfusion imaging. This test shows how well blood flows through the heart muscle. A tiny, safe amount of radioactive substance is given through a vein. A special camera takes pictures of the substance as it moves through the blood vessels of the heart. The test helps find areas of poor blood flow or damage in the heart.
  • CT angiogram. This test looks at the arteries that supply blood to the heart. It uses a powerful X-ray machine to create images of the heart and its blood vessels. The test can find any buildup of plaque in and on the walls of the coronary artery walls.
  • Exercise stress test. A stress test shows how well the heart works when you exercise. It often involves walking on a treadmill or riding a stationary bike while the heart is checked. If you can't exercise, you might get medicine that affects the heart like exercise does. This test is done only when you have no symptoms of acute coronary syndrome or another life-threatening heart condition when you are at rest. Other tests may be done during the stress test to see how well the heart works.

Treatment

The immediate goals of treatment for acute coronary syndrome are to:

  • Relieve pain and distress.
  • Improve blood flow.
  • Restore heart function quickly and as much as possible.

Long-term treatment goals are to:

  • Help the heart work better.
  • Manage risk factors.
  • Lower the risk of a heart attack.

Treatment may include medicine and heart procedures or surgery.

Medicines

Medicines are given to treat symptoms of acute coronary syndrome and to prevent complications.

  • Clot busters help break up a blood clot that's blocking an artery. These medicines also are known as thrombolytics.
  • Nitroglycerin improves blood flow by temporarily widening blood vessels.
  • Antiplatelet drugs help prevent blood clots from forming. They include aspirin, clopidogrel (Plavix) and prasugrel (Effient).
  • Beta blockers help relax the heart muscle and slow the heart rate. They decrease the demand on your heart and lower blood pressure. Examples include metoprolol (Lopressor, Toprol-XL) and nadolol.
  • Angiotensin-converting enzyme inhibitors, also called ACE inhibitors, widen blood vessels and improve blood flow. This helps the heart work better. Examples include lisinopril (Qbrelis, Zestril), benazepril (Lotensin) and others.
  • Angiotensin 2 receptor blockers, also called ARBs, help control blood pressure. They include irbesartan (Avapro), losartan (Cozaar) and others.
  • Statins lower the amount of cholesterol in the blood. They may stabilize fatty deposits, making them less likely to rupture and form a blood clot. Statins include atorvastatin (Lipitor, Atorvaliq), simvastatin (Zocor, Flolipid) and others.
  • Other cholesterol-lowering medications such as ezetimibe (Zetia).

Surgery and other procedures

Your healthcare professional may recommend a heart procedure or surgery to restore blood flow to the heart:

  • Angioplasty and stenting. This treatment uses a thin, flexible tube and tiny balloon to open clogged heart arteries. A surgeon inserts the tube in a blood vessel, usually in the groin or wrist, and guides it to the narrowed heart artery. A wire with a deflated balloon on the tip goes through the tube. The balloon is inflated, widening the artery. The balloon is deflated and removed. A mesh tube, called a stent, is usually placed in the artery to help keep it open.
  • Coronary artery bypass grafting, also called CABG — pronounced "cabbage." This major surgery involves taking a healthy blood vessel from the chest or leg area. This piece of healthy tissue is called a graft. A surgeon attaches the ends of the graft below a blocked heart artery. This creates a new path for blood to flow to the heart.

Lifestyle and home remedies

Lifestyle changes can help keep the heart healthy. Try these tips:

  • Don't smoke or use tobacco. If you smoke, quit. Talk to your healthcare team if you need help quitting. Also avoid secondhand smoke.
  • Eat healthy foods. Choose fruits, vegetables and whole grains. Limit sugar, salt and saturated fats.
  • Be active. Regular exercise helps improve heart health. Try to get at least 30 minutes of moderate or vigorous physical activity five or more days a week. Talk with your healthcare team about the amount and type of exercise that's best for you.
  • Check your cholesterol. Have your blood cholesterol levels checked regularly at a medical office. Avoid high-fat, high-cholesterol meat and dairy. If you have high cholesterol, your healthcare professional may recommend medicine to lower it.
  • Control your blood pressure. Uncontrolled high blood pressure increases the risk of serious health conditions. Have your blood pressure checked regularly by your healthcare professional. Ask what blood pressure reading is best for you.
  • Keep a healthy weight. Too much weight strains the heart. It also can lead to high cholesterol, high blood pressure, diabetes, heart disease and other conditions. Talk with your healthcare team to set realistic goals for weight.
  • Manage stress. Find ways to help reduce emotional stress. Some tips are to get more exercise, practice mindfulness and connect with others in support groups.
  • Limit alcohol. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and up to two drinks a day for men.
  • Practice good sleep habits. Poor sleep may increase the risk of heart disease and other chronic conditions. Adults should try to get 7 to 9 hours of sleep daily. Go to bed and wake at the same time every day, including on weekends. If you have trouble sleeping, talk to your healthcare team about strategies that might help.

Preparing for an appointment

If you have sudden chest pain or other symptoms of acute coronary syndrome, get emergency care right away or call 911.

How you describe your symptoms helps an emergency medical team make a diagnosis. Be prepared to answer the following questions.

  • When did the symptoms start?
  • How long did they last?
  • What symptoms are you currently having?
  • How would you describe the pain?
  • Where is the pain located?
  • On a scale of 1 to 10, with 10 being the worst, how bad is the pain?
  • Does anything make the symptoms better or worse?

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