Junctional rhythm is a type of heart rhythm disturbance where the electrical impulses that regulate the heartbeat originate from the atrioventricular (AV) node, rather than from the normal pacemaker, which is the sinoatrial (SA) node located in the right atrium. This can occur due to various reasons, such as damage to the heart's conduction system, electrolyte imbalances, or certain medications. The heart rate during junctional rhythm is typically between 40 and 60 beats per minute, which is slower than the normal sinus rhythm. The term "junctional" refers to the location of the impulse's origin, which is at the AV node, the junction between the atria and ventricles. In a normal sinus rhythm, the electrical activity originates from the SA node and depolarizes the atria before the signal is conducted to the ventricles. In contrast, with a junctional rhythm, the electrical signals start at the AV node and can cause the ventricles to contract before the atria, leading to a different sequence of heart muscle contractions. read more >>

Junctional rhythm describes an abnormal heart rhythm resulting from impulses coming from a locus of tissue in the area of the atrioventricular node, the "junction" between atria and ventricles. ... The electrical activity of sinus rhythm originates in the sinoatrial node and depolarizes the atria.read more >>