Question

The nurse reviews a clients ECG and notes P waves. With regard to the cardiac cycle, what does the P wave indicate?

A. atrial depolarization
B. ventricular repolarization
C. ventricular depolarization
D. Atrial repolarization

Answer 1

The P waves on an ECG represent atrial depolarization, which is the phase in the cardiac cycle when the atria contract and pump blood into the ventricles.

Step-by-step explanation:

The nurse observes P waves on the client's ECG (electrocardiogram) which indicate atrial depolarization. This phase of the cardiac cycle is when the atria's muscle cells become electrically charged, leading to atrial contraction (systole) and the subsequent pumping of blood into the ventricles. The other phases of the ECG are represented by the QRS complex, which signifies ventricular depolarization, and the T wave, which corresponds to ventricular repolarization. It is crucial to note that atrial repolarization is not individually represented on the ECG as it occurs simultaneously with the QRS complex and is therefore masked by the electrical activity of the ventricular depolarization.