ECG education

Diagnosing chest pain

Vivienne Miller



Articles in this section are inspired by, but not based on, real cases to illustrate the importance of knowledge about ECGs in relation to clinical situations in general practice. Management is not discussed in detail.

Key Points

  • Chest pain is common, but if an acute cardiac cause or other emergency cannot be excluded then the patient should be assumed to have these until proven otherwise.
  • In acute ST elevation myocardial infarction (STEMI), the first changes are hyperacute T waves, followed by ST elevation within the hour; T waves begin to invert at 12 to 24 hours; the baseline returns to normal at 24 hours, but T wave inversion lasts days to months.
  • Pathological Q waves are seen in the first few hours, evolve over days and are permanent.
  • Normal Q waves typically occur in the trace from the left-sided leads (chest leads V5 and V6 and limb leads 1 and aVL).