Fast Five Quiz: Myocardial Infarction Clinical Keys

Yasmine S. Ali, MD


November 13, 2020

Patients with typical acute MI usually present with chest pain and may have prodromal symptoms of fatigue, chest discomfort, or malaise in the days preceding the event; alternatively, typical STEMI may occur suddenly without warning.

The typical chest pain of acute MI is usually intense and unremitting for 30-60 minutes. It is retrosternal and often radiates up to the neck, shoulder, and jaw and down to the left arm. The chest pain is usually described as a substernal pressure sensation that is also perceived as squeezing, aching, burning, or even sharp. In some patients, the symptom is epigastric, with a feeling of indigestion or of fullness and gas. This may be the only reported symptom of MI in some patients.

MI occurs most often in the early morning hours. Mechanisms that may explain this circadian variation include the morning increase in sympathetic tone leading to increases in blood pressure, heart rate, coronary vascular tone, and myocardial contractility; the morning increase in blood viscosity, coagulability, and platelet aggregability; and the increased morning levels of serum cortisol and plasma catecholamines leading to sympathetic overactivity, thereby resulting in increased myocardial demand.

A high index of suspicion for MI should be maintained, especially when evaluating women, patients with diabetes, older patients, patients with dementia, patients with a history of heart failure, cocaine users, patients with hypercholesterolemia, and patients with a positive family history for early coronary disease. A positive family history includes any first-degree male relative aged 45 years or younger or any first-degree female relative aged 55 years or younger who experienced an MI or required coronary revascularization.

Symptoms of MI include the following:

  • Anxiety, commonly described as a sense of impending doom

  • Pain or discomfort in the arms, left shoulder, back, neck, jaw, or stomach

  • Lightheadedness, with or without syncope

  • Cough

  • Nausea, with or without vomiting

  • Profuse sweating

  • Shortness of breath

  • Wheezing

  • Rapid or irregular heart rate

  • Fullness, indigestion, or choking feeling

Read more about the presentation of MI.


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