What does "atrioventricular (AV) dissociation" refer to in cardiac physiology?

Atrioventricular (AV) dissociation refers to a condition where the atria and ventricles of the heart beat independently of each other. This occurs when there is a disruption in the normal conduction pathway that usually coordinates the contractions of the atria and ventricles. In a healthy heart, electrical impulses travel from the atria to the ventricles through the AV node, resulting in synchronized contractions. However, in AV dissociation, the atria may generate impulses that the ventricles do not respond to, often due to a block or dysfunction in the conduction system.

The consequences of AV dissociation can result in different rates of contraction between the atria and ventricles, leading to inefficient heart function and potentially serious clinical implications. This phenomenon is commonly observed in certain arrhythmias, pacing malfunction, or following a heart attack that affects the electrical conduction pathways.

Therefore, the identification of AV dissociation is critical for understanding the underlying issues in cardiac physiology and for determining the appropriate management strategies for patients experiencing this condition.