Rheumatic Endocarditis Most Commonly Affects Which Heart Valve

Rheumatic endocarditis primarily affects the mitral valve, making it the most vulnerable valve in the heart. This condition often leads to mitral valve stenosis, a narrowing of the valve opening that restricts blood flow. The primary pathological changes associated with rheumatic mitral stenosis include fibrosis and contraction of the valve leaflets and chordae tendineae, as well as adhesion between the leaflets. These structural alterations cause the valve to shift downward in position, sometimes forming a funnel-like shape with the wide end facing the left atrium and the narrow end pointing toward the left ventricle.

Pathophysiological Consequences of Mitral Stenosis

As the mitral valve becomes increasingly restricted, its opening area diminishes, leading to significant hemodynamic disturbances. This obstruction hampers the normal flow of blood from the left atrium to the left ventricle, resulting in elevated pressure within the left atrium. Over time, this can lead to left atrial enlargement, pulmonary hypertension, and eventually right heart failure if left untreated.

Prevalence and Coexisting Conditions

Among patients diagnosed with rheumatic heart disease, approximately 25% suffer from isolated mitral stenosis. However, in about 40% of cases, mitral stenosis occurs in conjunction with mitral regurgitation, where blood leaks backward into the left atrium. Additionally, the aortic valve is frequently affected simultaneously, leading to a more complex clinical presentation and potentially requiring more extensive treatment strategies.