Mitral annular disjunction

Overview of Mitral Annular Disjunction

Mitral Annular Disjunction

Diagram of the mitral valve, also known as the bicuspid valve.

Mitral Annular Disjunction (MAD) is a structural abnormality of the mitral valve apparatus, characterized by a separation between the mitral valve annulus and the left atrial wall. This condition is often associated with mitral valve prolapse and can lead to significant clinical implications, including mitral regurgitation and arrhythmias.

Anatomy and Pathophysiology

Anatomical illustration of the mitral valve.

The mitral valve is one of the four valves in the heart, located between the left atrium and the left ventricle. It consists of two leaflets, the anterior and posterior, which are anchored by the mitral annulus. In Mitral Annular Disjunction, there is a detachment or disjunction of the annulus from the left atrial wall, which can lead to excessive leaflet motion and prolapse.

The pathophysiology of MAD involves the abnormal displacement of the mitral annulus, which can result in increased stress on the valve leaflets and the chordae tendineae. This can lead to progressive myxomatous degeneration, a condition where the connective tissue of the valve becomes weakened and thickened.

Clinical Significance

Mitral Annular Disjunction is clinically significant due to its association with mitral valve prolapse and the potential for severe mitral regurgitation. Patients with MAD may present with symptoms such as palpitations, chest pain, and dyspnea. The condition is also linked to an increased risk of arrhythmias, including ventricular tachycardia and ventricular fibrillation, which can be life-threatening.

Diagnosis

The diagnosis of Mitral Annular Disjunction is typically made using echocardiography, which can visualize the separation between the mitral annulus and the left atrial wall. Advanced imaging techniques such as cardiac MRI may also be used to assess the extent of the disjunction and its impact on cardiac function.

Management

Management of Mitral Annular Disjunction involves regular monitoring and treatment of associated conditions such as mitral valve prolapse and mitral regurgitation. In some cases, surgical intervention may be necessary to repair or replace the mitral valve, especially if significant regurgitation or arrhythmias are present.

Histopathology

Histopathological image showing myxomatous degeneration of the mitral valve.

Histopathological examination of the mitral valve in cases of MAD often reveals myxomatous degeneration, characterized by the accumulation of proteoglycans and disruption of the normal collagen architecture. This degeneration contributes to the weakening and prolapse of the valve leaflets.

Related Pages

• Mitral valve prolapse
• Mitral regurgitation
• Echocardiography
• Cardiac MRI