Final answer:
A complete cardiac cycle in a healthy heart on an ECG is described by the P wave, QRS complex, and T wave, signifying atrial depolarization, ventricular depolarization, and ventricular repolarization respectively.
Step-by-step explanation:
The question pertains to a complete cardiac cycle as represented on an electrocardiogram (ECG). A complete cardiac cycle includes several key components which are visible as waves and complexes on an ECG reading. The correct description that denotes a complete cardiac cycle in a healthy heart among the given options is: P wave, QRS complex, and T wave. The P wave signifies the atrial depolarization, the QRS complex represents the ventricular depolarization, and the T wave indicates the ventricular repolarization. The repolarization of the atria is not visible on the ECG because it is masked by the QRS complex during ventricular depolarization.