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Acute coronary syndrome (ACS) encompasses unstable angina, ST elevation myocardial infarction (STEMI), and non-ST-elevation myocardial infarction (NSTEMI). It is the symptomatic cardiac end product of cardiovascular disease (CVD) resulting in reversible or irreversible cardiac injury, and even death.


The diagnosis of ACS requires two of the following: ischemic symptoms, diagnostic electrocardiogram (ECG) changes, or elevated serum marker of cardiac injury.

A. Symptoms

By themselves, signs and symptoms are not sufficient to diagnose or rule out ACS, but they start the investigatory cascade. Having known risk factors for coronary artery disease (CAD) (Table 20-1) or prior ACS increases the likelihood of ACS. Up to one-third of people with CAD progress to ACS with chest pain. While chest pain is the predominant symptom of ACS, it is not always present. Symptoms include the following:

  • Chest pain

    • Classic: substernal pain that occurs with exertion and alleviates with rest (In a person with a history of CAD, this called “typical” or “stable” angina)

    • Dull, heavy pressure in or on the chest

    • Sensation of a heavy object on the chest

    • Initiated by stress, exercise, large meals, sex, or any activity that increases the body’s demand on the heart for blood

    • Lasting >20 minutes

    • Radiating to the back, neck, jaw, left arm or shoulder

    • Accompanied by feeling clammy or sweaty

    • Associated with sensation of dry mouth (women)

    • Not affected by inspiration

    • Not reproducible with chest palpation

  • Right-sided chest pain, occasionally

    • More common in African-American patients

  • Pain high in the abdomen or chest, nausea, extreme fatigue after exercise, back pain, and edema can occur in anyone, but are more common in women

  • Extreme fatigue or edema after exercise

  • Shortness of breath

    • This can be the only sign in the elderly

    • More common in African-American than white patients

    • More common in women than men

  • Levine’s sign—chest discomfort described as a clenched fist over the sternum (the patient will clench his/her fist and rest it on or hover it over his/her sternum)

  • Angor anami—great fear of impending doom/death

  • Nausea, lightheadedness, or dizziness

  • Less commonly

    • Mild, burning chest discomfort

    • Sharp chest pain

    • Pain that radiates to the right arm or back

    • A sudden urge to defecate in conjunction with chest pain

Chest pain that is present for days, is pleuritic, is positional, or radiates to the lower extremities or above the mandible is less likely to be cardiac in origin.

Table 20–1.Risk factors for coronary artery disease.

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