Clinical presentation and early hazards of acute coronary syndrome
THE CONTEXT
Acute coronary syndrome may present with central chest pain, breathlessness, vomiting or collapse; myocardial infarction may also be painless.
Pain and breathlessness
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Chest pain at rest is the cardinal symptom. It occurs at the same sites as angina but is usually more severe and lasts longer.
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Pain is often described as tightness, heaviness or constriction. In acute myocardial infarction, it may be excruciating and accompanied by pallor.
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Most patients are breathless, and breathlessness may be the only symptom.
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Painless or silent myocardial infarction is particularly common in older patients and those with diabetes mellitus. Infarction may occur without physical signs.
Collapse and gastrointestinal symptoms
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Syncope is usually caused by an arrhythmia or profound hypotension.
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Vagal stimulation often causes vomiting and sinus bradycardia, particularly in inferior myocardial infarction.
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Opiates given for pain relief may cause or aggravate nausea and vomiting.
Early arrhythmic risk
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Ventricular fibrillation or asystole may cause sudden death immediately, often within the first hour.
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After this critical stage, dangerous arrhythmias remain possible, but the risk diminishes with each passing hour. Patients should avoid delaying calls for help when symptoms occur.
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Complications can occur in all forms of acute coronary syndrome but have become less frequent with immediate or early coronary revascularisation.