atrioventrikulaaristen

Atrioventrikulaariset (literally atrioventricular things) refers to structures and functions that connect the atria—the upper chambers of the heart—to the ventricles—the lower chambers. In human physiology the key atrioventricular components are the atrioventricular node (AV node), the bundle of His, and the right and left bundle branches. These elements form the only electrical conduction pathways that allow impulses generated in the sinoatrial node to reach ventricular muscle.

The AV node is located in the interatrial septum near the tricuspid valve. It receives impulses from the atria, briefly delays them, and then passes the signals down through the bundle of His. The His bundle divides into two branches that run within the interventricular septum and give rise to Purkinje fibres that spread excitation throughout the ventricles. This cascade ensures that the atria contract first, filling the ventricles, and then the ventricles contract, essential for efficient blood pumping.

In clinical cardiology atrioventricular pathology is common. Atrioventricular block occurs when conduction between the atria and ventricles is impaired, and can be classified into first‑degree (prolonged PR interval), second‑degree (Mobitz I or II), and third‑degree (complete block) forms. Electrocardiographic changes associated with such blocks are characterized by abnormal PR intervals and QRS morphology. Managing atrioventricular disorders often involves medications, pacemaker implantation, or ablation procedures.

The study of atrioventricular electrophysiology has led to advances in cardiac resynchronization therapy, catheter ablation of supraventricular tachycardias, and the development of modern pacemakers that emulate the natural sequence of AV conduction. Understanding these atrioventricular mechanisms is essential for diagnosing rhythm disturbances, guiding interventional therapy, and improving patient outcomes.