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.

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.
By Mayo Clinic Staff