What is an abnormal T wave?

An abnormal T wave is a deviation from the normal shape, amplitude, or polarity of the T wave in an electrocardiogram (ECG). The T wave represents the repolarization, or the recovery phase, of the ventricles after they have contracted to pump blood. It is typically upright and follows the direction of the preceding QRS complex, which represents ventricular depolarization. Abnormal T waves can indicate various cardiac conditions, electrolyte imbalances, or the effects of certain medications. Key points to consider: 1. Shape: Normally, the T wave is rounded and symmetrical. An abnormal T wave might be notched, slurred, or have a different shape. 2. Amplitude: Low-amplitude T waves can be a sign of conditions like ischemia or electrolyte disorders. 3. Polarity: Inversion of the T wave, where it is inverted relative to the QRS complex, can be seen in various heart diseases, such as coronary artery disease, or may be a side effect of certain drugs. 4. Leads: The direction of the T wave should be consistent with the QRS complex in most leads, except for lead V2 where a T wave inversion can be normal in some individuals. It's important to note that the interpretation of T wave abnormalities requires a comprehensive approach, taking into account the patient's history, physical examination, and other ECG findings.

The T wave is the most labile wave in the ECG. T wave changes including low-amplitude T waves and abnormally inverted T waves may be the result of many cardiac and non-cardiac conditions. The normal T wave is usually in the same direction as the QRS except in the right precordial leads (see V2 below).