Question 15.3

The ECG shown on page 15 (ECG 15.3) is from a 47 year-old female with breast cancer who presented with shortness of breath.

a)    Describe the abnormalities. (20% marks)

b)    What is the likely underlying diagnosis? (10% marks)



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College answer


  1. Low voltage QRS complexes
  2. Electrical alternans
  3. Tachycardia
b) Pericardial effusion


This ECG was stolen from the LITFL page on ECG changes in massive pericardial effusion. The alternans is most clearly visible in the rhythm strip, which is V1. 


Usher, Bruce W., and Richard L. Popp. "Electrical alternans: mechanism in pericardial effusion." American heart journal 83.4 (1972): 459-463.