T wave

Overview of the T wave in electrocardiography

Overview

The T wave is a component of the electrocardiogram (ECG) that represents the repolarization of the ventricles in the heart. It follows the QRS complex and precedes the U wave, if present. The T wave is an important indicator of the electrical activity and health of the heart.

Characteristics

The T wave is typically upright in most leads of a standard 12-lead ECG, except in lead aVR where it is normally inverted. The shape, amplitude, and duration of the T wave can provide valuable information about the cardiac condition.

Normal T Wave

Normal T wave in an ECG

A normal T wave is asymmetrical, with a gradual ascent and a more rapid descent. The amplitude of the T wave is usually less than 5 mm in the limb leads and less than 10 mm in the precordial leads.

Abnormal T Waves

Abnormalities in the T wave can indicate various cardiac conditions:

• Inverted T waves: May suggest myocardial ischemia, myocardial infarction, or ventricular hypertrophy.
• Peaked T waves: Often associated with hyperkalemia.
• Flattened T waves: Can be a sign of hypokalemia or myocarditis.

Clinical Significance

The analysis of the T wave is crucial in diagnosing and managing cardiac conditions. Changes in the T wave can indicate electrolyte imbalances, ischemic heart disease, and other cardiac pathologies.

Related pages

• Electrocardiography
• QRS complex
• U wave
• Myocardial ischemia
• Hyperkalemia