CAMRT Radiography Practice Exam

What ECG wave signifies the period of cardiac systole?

1. T wave

2. P wave

3. QRS complex

4. R wave

The correct answer is: P wave

The wave that signifies the period of cardiac systole is the QRS complex. This complex represents the electrical activity associated with the depolarization of the ventricles, which is crucial for the contraction of the heart muscle during systole. When the ventricles depolarize, they contract and pump blood out of the heart, marking the active phase of the cardiac cycle known as systole. The P wave, which was indicated as the correct choice, actually corresponds to the depolarization of the atria, leading to atrial contraction, not the ventricles. The T wave represents ventricular repolarization and occurs after systole when the heart is in the diastolic phase. The R wave is a component of the QRS complex and specifically pertains to the upward deflection, but does not encompass the entire process of cardiac systole. Thus, the QRS complex is the accurate answer for identifying when the heart is actively pumping blood.