AVklaffene

AVklaffene, or atrioventricular valves, are the heart valves between the atria and ventricles. There are two: the tricuspid valve on the right, between the right atrium and right ventricle, and the mitral valve on the left, between the left atrium and left ventricle. They consist of leaflets (cusps) attached to a fibrous annulus, with chordae tendineae anchored to papillary muscles. Their primary function is to permit one-way blood flow from the atria to the ventricles and to prevent backflow during ventricular systole.

The valves open during ventricular filling (diastole) when atrial pressure exceeds ventricular pressure, and close during systole when ventricular pressure rises, producing the S1 heart sound. The leaflets are supported by the chordae tendineae and papillary muscles to prevent prolapse as the ventricles contract. The valves are largely avascular and rely on the surrounding cardiac structures for nutrition and repair.

Disorders of the AVklaffene include stenosis (narrowing) and regurgitation (incompetence). Mitral stenosis and mitral regurgitation affect the left-sided valve, while tricuspid stenosis and tricuspid regurgitation affect the right-sided valve. Causes include rheumatic disease, calcification, infective endocarditis, degenerative changes, or functional dilation of the ventricles. Symptoms vary but can include shortness of breath, fatigue, edema, or palpitations; auscultation may reveal characteristic murmurs and the S1/S2 sounds.

Diagnosis is primarily via echocardiography, with additional imaging or ECG as needed. Treatment ranges from medical management for symptoms to surgical repair or replacement. Valve repair is preferred when feasible; valve replacement can use mechanical or bioprosthetic prostheses, with transcatheter options available for selected cases.