The electrocardiogram (ECG) complex represents the electrical events occurring in which timeframe?

The electrocardiogram (ECG) complex represents the electrical events occurring during one cardiac cycle. A cardiac cycle encompasses all the electrical and mechanical events that occur from the beginning of one heartbeat to the beginning of the next. This includes the depolarization and repolarization of the atria and ventricles, which are reflected as specific waves on the ECG, namely the P wave, QRS complex, and T wave.

Understanding this timeframe is crucial because it allows healthcare professionals to interpret the electrical activity of the heart accurately. Changes in the normal pattern of these waves can indicate various cardiac conditions. The other options relate to different physiological processes or measurements that do not specifically correlate to the representation of the heart's electrical activity as seen on an ECG.