Which of the following waveforms comes after the T wave and is visible on an EKG strip?

The U wave is indeed the waveform that follows the T wave on an electrocardiogram (EKG) strip. It represents the repolarization of the Purkinje fibers or the papillary muscles in the ventricles, although its precise origin is still a subject of study. The U wave can sometimes be seen in normal individuals, especially at slower heart rates. It typically appears as a gentle upward deflection following the T wave.

Understanding the U wave's presence is crucial in interpreting an EKG, as it can provide insights into the heart's electrical activity following ventricular repolarization. In certain situations, particularly when there is electrolyte imbalance or other cardiac conditions, the U wave can be more pronounced or altered in appearance, which can be significant for diagnosing potential issues.

The other waveforms, such as the P wave and Q wave, occur at different times during the cardiac cycle: the P wave represents atrial depolarization, while the Q wave is part of the QRS complex, which signifies ventricular depolarization. Therefore, these waves would not be found after the T wave on an EKG strip.