How can the P waves be affected during a junctional escape rhythm?

How can the P waves be affected during a junctional escape rhythm?

• A. P waves are absent
• B. P waves appear upright
• C. P waves are inverted
• D. All P waves follow the QRS complex

Answer: (C)

In a junctional escape rhythm, the P waves can indeed be inverted. This occurs because the escape rhythm originates from the AV junction, which is situated near the atrioventricular node. When the heart's electrical impulses are initiated at this junctional region instead of the sinoatrial (SA) node, the depolarization wave moves in an abnormal direction.

As a result, when the atria are activated after the junctional focus has fired, the direction of the depolarization is such that it moves away from the electrode recording the EKG. This is why the P waves appear inverted on the EKG. It is important to note that while there can be instances where P waves are absent, they can also appear after the QRS complex when there is an escape rhythm. However, if they are present, the typical expectation is for them to be inverted, reflecting the change in the origination point of the electrical impulse.

Thus, the correct identification of the P waves in this context emphasizes the unique characteristic of the junctional escape rhythm compared to rhythms originating from the SA node.