What does the term "junctional rhythm" refer to?

The term "junctional rhythm" specifically refers to a heart rhythm that originates from the atrioventricular (AV) node. In a junctional rhythm, the electrical impulses that typically begin at the sinoatrial (SA) node are either absent, blocked, or fail to reach the heart due to certain conditions. Consequently, the AV node takes over as the primary pacemaker of the heart. This results in distinctive characteristics observed on an EKG, including a regular rhythm, often a lower heart rate, and P waves that may be absent or appear inverted.

The absence of proper SA node functioning leads to the AV node initiating contractions, which is why junctional rhythms are classified under rhythms originating specifically from the AV area of the heart. This understanding emphasizes the critical role of the AV node when higher pacemaker sites fail, showcasing how the heart can adapt to ensure continued function even when its primary system is compromised.