HisPurkinjesystemet

The His–Purkinje system (His-Purkinje system) is the heart's specialized conduction network that coordinates the timing of ventricular contraction. It comprises the atrioventricular (AV) node, the bundle of His, the right and left bundle branches, and the Purkinje fibers that spread through the subendocardial ventricular myocardium.

Electrical impulses typically begin in the sinoatrial node and travel through the atria to the AV node, which inserts a brief delay to allow atrial systole. From the AV node, impulses pass into the His bundle in the upper interventricular septum, then divide into the right and left bundle branches and finally into Purkinje fibers that rapidly distribute the impulse to the ventricles, enabling near-simultaneous activation.

Functionally, this system ensures coordinated, efficient ventricular contraction and maintains stable heart rate. Pathologies affecting it—such as ischemia, infarction, fibrosis, or degenerative disease—can cause conduction blocks (e.g., AV block, bundle-branch block) and arrhythmias. Electrical disturbance is often reflected on the ECG by prolonged PR interval, widened QRS, or complex ventricular rhythms. Treatments such as pacemakers or strategies that directly engage the His-Purkinje pathway aim to restore or preserve physiologic conduction.

Anatomically, the His-Purkinje network is predominantly located within the endocardium of the ventricles, with the bundle branches crossing the interventricular septum and Purkinje fibers terminating beneath the ventricular endocardial surface.