What does the T wave indicate in an EKG?

The T wave in an EKG represents ventricular repolarization. This is a crucial phase of the cardiac cycle where the ventricles, after having contracted to pump blood out to the body and lungs, undergo a process to restore their electrical charge to a resting state. It follows the QRS complex, which corresponds to ventricular depolarization (the actual contraction of the ventricles). During repolarization, the muscle fibers in the ventricles reset their electrical state in preparation for the next heartbeat. A normal T wave is typically upright in most leads, indicating proper ventricular repolarization, while abnormalities in the T wave can suggest underlying cardiac issues such as ischemia or electrolyte imbalances.