Certified EkG technician (CET) Practice Exam

What components make up a complete cardiac cycle?

1. P wave, QRS complex, and T wave

2. Atrial contraction and ventricular relaxation

3. Heart rate and blood pressure

4. Diastole and systole

The correct answer is: P wave, QRS complex, and T wave

The components that make up a complete cardiac cycle primarily involve the electrical activity of the heart, which is represented by the P wave, QRS complex, and T wave. This is essential because the cardiac cycle encapsulates the sequence of events that occur during one heartbeat, including the contraction and relaxation phases of the heart chambers, which are driven by electrical impulses. The P wave reflects atrial depolarization, leading to atrial contraction. The QRS complex indicates ventricular depolarization, which corresponds with ventricular contraction. The T wave represents ventricular repolarization, occurring as the ventricles relax. Collectively, these components form the foundation for understanding how the heart beats and maintains circulation. Other options, while relevant to cardiac function, do not define the complete cardiac cycle in terms of its primary electrical and mechanical activities. Atrial contraction and ventricular relaxation describe phases but do not capture the entirety of the cardiac cycle. Heart rate and blood pressure are important physiological parameters but are not components of the cardiac cycle itself. Diastole and systole refer to the phases of movement and pressure within the heart but do not provide the detailed electrical events that characterize the cardiac cycle. Thus, the choice highlighting the P wave, QRS complex, and T wave accurately encompasses