Normal

• Amplitude: 1/3 - 2/3 of the R wave
• Direction: same as the QRS complex
  • Positive in all leads except the right-sided leads (aVR, III, V1)

Abnormal

• Hyperacute T (> 2/3 of RR)
• TWI
  • Ischemia: NSTEMI (+ ST D), Hypertrophic HOCM - Hypertrophic Cardiomyopathy , Angina (+ST D), STEMI (+ ST E)
  • Brain injury (Cerebral Haemorrhage ECG → surge of catecholamine) - systemic (diffused)
  • Past MI