From the Guidelines
Mitral regurgitation causes blood to regurgitate from the left ventricle into the left atrium. This occurs when the mitral valve, which normally ensures one-way blood flow from the left atrium to the left ventricle during diastole, fails to close properly during systole. As a result, when the left ventricle contracts to pump blood forward into the aorta, some blood flows backward (regurgitates) into the left atrium through the incompetent mitral valve. This backflow reduces cardiac efficiency and can lead to volume overload in the left atrium, pulmonary congestion, and eventually heart failure if severe and untreated. The regurgitation occurs specifically during ventricular systole, when pressure in the left ventricle exceeds that in the left atrium.
Key Points
- Mitral regurgitation is characterized by the backflow of blood from the left ventricle into the left atrium during systole 1.
- The severity of mitral regurgitation is related to the magnitude of the regurgitant volume, which results in left ventricular dilation and increases in left atrial pressure and volume 1.
- Common causes of mitral regurgitation include mitral valve prolapse, rheumatic heart disease, infective endocarditis, and structural abnormalities of the valve apparatus.
- The management of mitral regurgitation depends on the severity of the condition, with surgical intervention recommended for severe cases or those with symptoms or left ventricular dysfunction 1.
Clinical Implications
- Mitral regurgitation can lead to significant morbidity and mortality if left untreated, with potential complications including heart failure, pulmonary congestion, and arrhythmias.
- Accurate diagnosis and assessment of mitral regurgitation are crucial for determining the appropriate treatment strategy.
- Guideline-directed management and therapy, including surgical intervention when necessary, can improve outcomes and reduce the risk of complications in patients with mitral regurgitation 1.
From the Research
Mitral Regurgitation Location
- Mitral regurgitation (MR) is characterized by systolic retrograde flow from the left ventricle into the left atrium 2.
- The mitral valve permits blood to flow from the left atrial (LA) to left ventricle (LV) during diastole and sealing of the LA from the LV during systole, and abnormal function of any component can result in MR 3.
- MR involves the backflow of blood from the left ventricle into the left atrium during systole, indicating that the regurgitation occurs in the left atrium 4, 2, 5.
Pathophysiology of Mitral Regurgitation
- The pathophysiology of MR is complex and involves the interplay between the mitral valve, left ventricle, and left atrium 6.
- Chronic MR typically progresses insidiously over many years and can lead to poor prognosis if left untreated 2.
- The severity of MR can be assessed by various techniques, including Doppler echocardiography, and mitral valve surgery is the only treatment of proven efficacy 2.
Interaction between Mitral Valve and Left Ventricle
- The mitral valve apparatus has anatomical and functional relationships with the left ventricle, and impaired coordination between the two can lead to valvular dysfunction 5.
- The interaction between the mitral valve and left ventricle is crucial in understanding the mechanisms of MR and developing therapeutic strategies 5, 6.