atrioventriculaire

Atrioventriculaire is an adjective used in anatomy and cardiology to describe structures, pathways or processes that involve the atria and the ventricles of the heart, or the elements located between them. It is commonly applied to the atrioventricular (AV) conduction system, the atrioventricular valves, and disorders affecting communication between the atria and ventricles.

The atrioventricular conduction system includes the atrioventricular node (nœud atrioventriculaire) and the conducting pathways that connect the atria to the ventricles, such as the bundle of His and the Purkinje fibers. The AV node provides a physiologic delay that coordinates atrial and ventricular contraction, allowing adequate ventricular filling. The atrioventricular valves, namely the mitral and tricuspid valves, separate the atria from the ventricles and prevent backflow during systole.

Physiologically, an electrical impulse typically originates in the sinoatrial node, spreads through the atria, reaches the AV node where a delay occurs, then travels via the His-Purkinje system to stimulate the ventricles. The atrioventricular interval is reflected on the electrocardiogram as the PR segment or PR interval.

Clinical relevance includes disorders of atrioventricular conduction, such as atrioventricular block of varying degrees, which can cause bradycardia or syncope. Arrhythmias related to the AV pathway include atrioventricular nodal reentrant tachycardia and other AV accessory-pathway tachycardias. Pathologies may also involve the structure or function of the atrioventricular valves, contributing to valvular disease. Diagnosis and management depend on the specific mechanism and severity.