What are the common symptoms of a posterior myocardial infarction (heart attack)?

Common Symptoms of Posterior Myocardial Infarction

Hypotension, nausea and vomiting, extreme weakness/fatigue, and atypical chest pain or pressure that may radiate to the back are the most common symptoms of posterior myocardial infarction (PMI). 1

Clinical Presentation of Posterior MI

Posterior myocardial infarction presents with a constellation of symptoms that often differ from the "classic" heart attack presentation, making it challenging to diagnose:

Primary Symptoms

• Atypical chest discomfort:

  • Less severe than typical MI pain
  • May radiate to the back or between shoulder blades (interscapular region) 1
  • Can be mistaken for other conditions

• Autonomic symptoms (very common):

  • Nausea and vomiting 1, 2
  • Diaphoresis (sweating) 1, 2
  • Pallor 1

• Hemodynamic changes:

  • Hypotension (a significant clinical sign that should not be overlooked) 1

• General symptoms:

  • Extreme weakness or fatigue 1
  • Shortness of breath/dyspnea (often the predominant symptom) 1
  • Epigastric discomfort (often mistaken for indigestion) 1

Special Populations and Atypical Presentations

The American Heart Association notes that certain populations are more likely to present with atypical symptoms 1:

• Women
• Elderly patients
• Diabetic patients

These groups may experience:

• Unusual fatigue
• Sleep disturbances
• Shortness of breath without chest pain
• Indigestion
• Anxiety
• Generalized weakness
• Confusion or changes in mental status
• Syncope (fainting)
• Stroke-like symptoms 1, 3, 4

Diagnostic Challenges

PMI is often missed because:

1. The standard 12-lead ECG doesn't directly visualize the posterior wall of the left ventricle 1, 5, 6
2. ECG changes may be subtle (ST depression in leads V1-V3 rather than classic ST elevation) 1
3. Additional posterior leads (V7-V9) are required for direct visualization 1, 5

Clinical Pearls

• Don't dismiss gastrointestinal symptoms (nausea, vomiting, epigastric discomfort) without considering cardiac causes, especially in high-risk patients 1
• Don't wait for "typical" chest pain before considering PMI diagnosis 1
• Hypotension is a significant clinical sign that should prompt consideration of PMI 1
• Early recognition and treatment significantly reduce morbidity and mortality 1

Answer to Multiple Choice Question

Based on the evidence, the correct answer is option i. Hypotension, nausea and vomiting, extreme weakness/fatigue, any type of chest pain or pressure. This is pretty individual.

This option most accurately reflects the constellation of symptoms described in the guidelines, acknowledging both the common presentations and the individual variability in symptoms 1, 2.