Mitral Regurgitation Quiz

Understanding Mitral Regurgitation: A Comprehensive Guide

Mitral regurgitation (MR) is a common valvular heart disease where the mitral valve does not close properly, causing blood to leak backward from the left ventricle into the left atrium during systole. This guide provides an overview of its causes, diagnosis, and treatment, relevant for medical students, healthcare professionals, and patients seeking to understand the condition.

What is Mitral Regurgitation (MR)?

In a healthy heart, the mitral valve acts as a one-way gate between the left atrium and left ventricle. MR occurs when this valve fails, leading to an inefficient pumping action. The condition can be acute, developing suddenly, or chronic, progressing over many years. The severity is graded from mild to severe based on the volume of blood that leaks backward (regurgitant volume).

Primary vs. Secondary Mitral Regurgitation

It’s crucial to distinguish between two main types of MR:

• Primary (Degenerative) MR: This type involves a structural problem with the mitral valve leaflets or chordae tendineae themselves. The most common cause is mitral valve prolapse (MVP), where the leaflets bulge back into the left atrium.
• Secondary (Functional) MR: Here, the mitral valve is structurally normal, but it fails to close properly due to changes in the left ventricle’s size or shape, often from conditions like ischemic heart disease or dilated cardiomyopathy.

Common Causes and Risk Factors

The etiology of MR is diverse and includes:

• Mitral valve prolapse (most common cause of primary MR)
• Rheumatic heart disease
• Infective endocarditis
• Coronary artery disease leading to papillary muscle dysfunction or rupture
• Cardiomyopathy (dilated or hypertrophic)
• Congenital heart defects

Recognizing the Symptoms of MR

Mild to moderate chronic MR may be asymptomatic for years. As the condition worsens, the left ventricle and atrium must work harder, leading to symptoms such as shortness of breath (dyspnea), especially with exertion or when lying down, fatigue, heart palpitations, and swelling in the legs (edema).

The Diagnostic Process: From Stethoscope to Echocardiogram

Diagnosis begins with a physical exam and listening for the characteristic heart murmur. The gold standard for confirming the diagnosis, assessing severity, and determining the underlying cause is transthoracic echocardiography (TTE). This non-invasive ultrasound provides detailed images of the valve’s structure and function, and Doppler imaging quantifies the regurgitant flow.

Modern Treatment Strategies for Mitral Regurgitation

Management depends on the severity of MR, the presence of symptoms, and the patient’s overall health. Options range from medical management to surgical or percutaneous intervention. For asymptomatic patients with severe primary MR, guidelines recommend intervention if there are signs of left ventricular dysfunction (e.g., LVEF < 60%). For symptomatic patients, mitral valve repair is generally preferred over replacement. Transcatheter edge-to-edge repair (TEER), such as the MitraClip device, offers a less invasive option for high-risk surgical candidates.

This content is for informational and educational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.