Which of the following is true regarding the P wave in premature atrial contraction?

In premature atrial contractions (PACs), the P wave is typically present, which distinguishes PACs from other types of ectopic beats. The P wave may be normal in appearance or it might be hidden within the preceding T wave of the previous heartbeat, depending on the timing of the contraction. This can occur because the PAC happens early in the cardiac cycle, potentially overlapping with the T wave of the preceding beat.

A common feature of PACs is that their P wave characteristics can vary; they may be similar to normal sinus P waves or may appear different if the ectopic focus is in a particular region of the atria. However, it's crucial to note that P waves are always present in PACs but may not be easily visible in every case. This understanding underscores the importance of careful observation in rhythm analysis.