Myocardial Infarction

EKG in myocardial infarction (MI):

· ST elevation > 1 small box in two contiguous leads

· > 2 small boxes for leads V2- V3

· Reciprocal ST depression in opposite leads

· Contiguous leads:

· STEMI evolution:

Tall, peaked T waves

↓

ST segment elevation

(first concave, then convex and finally merging with T wave)

↓

ST returns to baseline with development of Q waves

and T wave inversions

· Old MI: Persistent Q waves that are deep (> 1 small square) and broad (> 1 small square) with or without T wave inversions

Miscellaneous:

EKG in Hyperkalemia: Tall, peaked T waves (diffuse) → prolonged PR interval → widened QRS →disappearance of P waves → QRS merges with T wave to form sinewave pattern