T wave abnormalities

The T wave, together with the ST segment, represents ventricular repolarization. T wave abnormalities can be caused by a variety of disorders including:

  • Ischemia, subendocardial and transmural ischemia.
  • Electrolyte disturbances, especially potassium-related
  • Aneurysms (balloon-like malformations) of the blood vessels of heart
  • Hypertrophy, especially left ventricular hypertrophy
  • Intraventricular conduction disturbances: LBBB, RBBB, and non-specific intraventricular conduction disturbances

 

 

 



 

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This ECG tracing shows inverted T waves in leads I, aVL, and in leads V2 to V6 as caused by an anterolateral transmural ischemia.

 

 



 
 

T wave inversion

The finding of inverted T waves in an isolated lead is of little diagnostic value. Left ventricular hypertrophy and conduction abnormalities like LBBB and RBBB are often associated with inverted T waves on the ECG.

When inverted T waves are seen on the ECG of a patient complaining of chest pain, the clinician should presume that these T wave inversions are caused by ischemia until proven otherwise. To rule out or rule in ischemia, previous ECG’s should be analyzed, especially those tracings obtained when the patient had no symptoms or complaints

The finding of T wave inversion in most leads and not localized to a specific region of the heart is suggestive of a systemic disorder like hypoxia, anemia, or electrolyte disturbances or a disease affecting all regions of the heart like pericarditis or myocarditis.