Wednesday, 10 January 2018

ECG of the Week - 8th January 2018 - Interpretation

The following ECG is from a 31 yr old female who is 5 days post-partum she was brought to the Emergency Department following a episode of collapse. On arrival to the Emergency Department she was hypotensive ( Systolic BP ~80 mmHg) with an altered conscious level complaining of chest pain and headache.



Click to enlarge
Rate:
  • 60 bpm
Rhythm:
  • Regular
  • Sinus rhythm
Axis:
  • Normal
Intervals:
  • PR - Normal
  • QRS - Normal
Additional:

  • ST Elevation in leads aVR & aVL (<1mm font="">
  • Upsloping ST depression in leads V2-6 
    • Maximal in leads V3-4
  • Flat ST depression in the inferior leads
  • Prominent T waves in leads V2-4 

Interpretation:

  • Features consistent with a De Winter's pattern
    • Suggesting potential LAD pathology
    • DDx Demand ischaemia / perfusion mismatch

Given the patients age and medical history broader differentials for shock and ischaemic ECG features would be:

  • PE
  • Sepsis
  • Endocrine - Sheehan's Syndrome


What happened ?



The patient was initially treated with iv fluid, analgesia and broad spectrum iv antibiotics ( as initial broad DDx included sepsis). Following review of the initial ECG urgent cardiology input was obtained and an emergent CTPA was performed to exclude PE as a potential cause. On return from a negative CTPA the patient complained of further chest pain, repeat ECG below:
Click to enlarge
Clear anterolateral ST elevation and inferior ST depression. The patient was transferred for urgent angiography which showed a 90% mid LAD lesion treated with bioresorbable stent. Subsequent CTPA revealed a coronary artery dissection as the cause for the acute LAD lesion.

Coronary Artery Dissection
This is a rare phenomena occurring in ~4% of all acute MI's. Approximately 90% of cases occur in females and it accounts for 1/4 of MI's in the under 50 yr old age group. Recurrence rate is between 13-18%.

There are multiple risk factors including:

  • Fibromuscular dysplasia
  • Pregnancy
  • Connective tissue disorders
  • Systemic inflammatory conditions
  • Intense exercise
  • Intense emotional stress
  • Labour and delivery
  • Valsalva-like events
  • Sympathomimetic use

References / Further Reading

Life in the Fast Lane

Textbook
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.