Clinical Findings

Symptoms
1. Premonitory pain
One-third of patients give a history of alteration in the pattern of angina, recent onset of typical or atypical angina, or unusual “indigestion” or pressure or squeezing felt in the chest.

2. Pain of infarction
Most infarctions occur at rest unlike anginal episodes, and more commonly in the early morning. The pain is similar to angina in location and radiation but is more severe, and it builds up rapidly or in waves to maximum intensity over a few minutes or longer. Nitroglycerin has little effect; even opioids may not relieve the pain.

3. Associated symptoms
Patients may break out in a cold sweat, feel weak and apprehensive, and move about, seeking a position of comfort. They prefer not to lie quietly. Light-headedness, syncope, dyspnea, orthopnea, cough, wheezing, nausea and vomiting, or abdominal bloating may be present singly or in any combination.

4. Painless infarction
In a minority of cases, pain is absent or minor and is overshadowed by the immediate complications. As many as 25% of infarctions are detected on routine ECG without there having been any recallable acute episode.

5. Sudden death and early arrhythmias
Approximately 20% of patients with acute infarction will die before reaching the hospital; these deaths are usually in the first hour and are chiefly due to ventricular fibrillation.