What does the U wave appear after on an electrocardiogram?

The U wave is a small, typically positive deflection that appears on an electrocardiogram (ECG) after the T wave, which follows the QRS complex. The T wave represents the repolarization of the ventricles after they have contracted. The U wave is thought to be associated with the repolarization of the Purkinje fibers or the ventricular myocardium, although its exact origin and significance are not fully understood.

Understanding the sequence of waves on an ECG is crucial for interpreting cardiac electrical activity. It helps medical professionals analyze heart rhythm and function. In this case, recognizing that the U wave directly follows the T wave is key in identifying the U wave’s morphology and any clinical relevance it may hold in various conditions, such as electrolyte imbalances or ventricular hypertrophy.