ST segment elevation

Introduction

Elevation of the ECG ST segment.

Also see ST segment elevated myocardial infarction.

Etiology

• myocardial ischemia
  • acute coronary syndrome
  • myocardial infarction (MI)
• transmural or subepicardial injury
  • left ventricular aneurysm
  • cardiomyopathy
    • stress cardiomyopathy (broken heart syndrome)
• pericarditis
  • diffuse, convave upward
  • no reciprocal ST segment depression
• coronary vasospasm
• acute stroke
• severe hypercalcemia
• occasionally in healthy young African-American men

Pathology

• associated with fibrin deposition, thus the indication for fibrinolytic therapy

Diagnostic procedures

• electrocardiogram
  • 1 mm in 2 contiguous leads is considered significant elevation
• ST segment elevation in ECG leads II, III -> inferior wall MI
  • obtain right sided leads to assess right ventricular MI
    • ST segment elevation in right-sided lead V4 (V4R) is the most sensitive indicator for right ventricular MI
• ST segment elevation in ECG leads V1-V4 -> anterior wall MI

* ST segment elevation surrogates:

• new left bundle-branch block (LBBB)
• tall R & ST segment depression in leads V1-V4 (posterior wall MI)

Differential diagnosis

• pericarditis
  • diffuse ST segment elevation
  • diffuse PR interval depression
• left ventricular wall aneurysm
• normal variant

More general terms

• ECG ST segment

Additional terms

• ECG changes in myocardial ischemia
• ST segment depression
• ST segment elevated myocardial infarction (STEMI)