In an EKG, which component is typically seen as a reflection of the atrial contraction?

The P Wave is associated with the electrical activity that occurs during atrial contraction. It represents the depolarization of the atria, which is the first step in the cardiac cycle that leads to atrial contraction. When the atria depolarize, they generate an electrical impulse that spreads across their muscle fibers, causing them to contract and pump blood into the ventricles. This electrical activity is what is visually represented on an EKG as the P Wave.

The QRS Wave corresponds to the depolarization of the ventricles, which is responsible for ventricular contraction and is seen after the P Wave in a normal EKG tracing. The T Wave represents the repolarization of the ventricles, and the U Wave, while not always present, is thought to represent the repolarization of the papillary muscles or the Purkinje fibers, and does not relate to atrial contraction directly. Therefore, the P Wave is the correct answer as it specifically indicates the electrical event that signifies atrial contraction.