Mitral annular disjunction

Mitral valve * Válvula bicúspide

Mitral Valve RK

Histopathology of mitral valve with myxomatous degeneration

Mitral Annular Disjunction (MAD) is a structural abnormality of the heart where there is a separation or disjunction between the mitral valve annulus and the cardiac muscle of the left ventricular free wall. This condition is significant because it can be associated with various cardiac pathologies, including mitral valve prolapse (MVP), cardiomyopathy, and arrhythmias. Understanding MAD is crucial for diagnosing and managing patients with mitral valve disorders and those at risk of sudden cardiac death.

Etiology and Pathophysiology

Mitral Annular Disjunction is characterized by a detachment of the mitral valve's fibrous annulus from the myocardium, specifically the junction where the atrium meets the ventricle. This separation can lead to excessive mobility of the mitral valve leaflets, contributing to the development of mitral valve prolapse. The exact cause of MAD is not fully understood, but it is believed to be related to degenerative changes in the cardiac structure, possibly influenced by genetic predispositions.

Clinical Presentation

Patients with Mitral Annular Disjunction may be asymptomatic or present with symptoms related to associated conditions such as mitral valve prolapse. Symptoms can include palpitations, chest pain, fatigue, and in severe cases, congestive heart failure. MAD is also associated with an increased risk of ventricular arrhythmias and sudden cardiac death, especially in patients with significant mitral valve prolapse.

Diagnosis

Diagnosis of Mitral Annular Disjunction typically involves imaging techniques that can visualize the structural abnormalities of the mitral valve and its apparatus. Echocardiography is the primary tool used, with particular attention to the two-dimensional and Doppler studies that can reveal the presence of disjunction and its effects on mitral valve function. Cardiac magnetic resonance imaging (MRI) can also provide detailed images of the mitral valve and its annulus, offering valuable information for diagnosis and assessment of the condition's severity.

Treatment

The treatment for Mitral Annular Disjunction focuses on managing symptoms and reducing the risk of complications, such as arrhythmias and heart failure. In asymptomatic patients or those with mild symptoms, regular monitoring and conservative management may be sufficient. Pharmacological treatment can include beta-blockers or other medications to manage arrhythmias and heart failure symptoms. In cases where MAD leads to severe mitral valve prolapse or significant mitral regurgitation, surgical intervention, such as mitral valve repair or replacement, may be necessary.

Prognosis

The prognosis for patients with Mitral Annular Disjunction varies depending on the presence and severity of associated conditions like mitral valve prolapse and ventricular arrhythmias. With appropriate management, many patients can lead normal lives. However, those with significant complications may have a poorer prognosis and require more aggressive treatment strategies.