What is the typical P wave appearance in junctional escape rhythms?

In junctional escape rhythms, the P wave typically appears inverted or may be absent entirely. This occurs because the electrical impulse originates from the junctional tissue, which is located near the atrioventricular node. Since the junctional focus is positioned lower in the conduction pathway, the depolarization wave moves in the opposite direction compared to normal sinus rhythm, leading to inverted P waves when they are present. Additionally, in some cases, the P waves may not show at all because the junctional rhythm can occur below the atrial level, resulting in a situation where the atria are not depolarized by the natural pacing from the SA node. This characteristic feature is crucial for identifying junctional rhythms and distinguishing them from other types of cardiac rhythms.