Rheumatic Heart Valve Disease Most Commonly Affects These Valves

Rheumatic heart valve disease primarily affects the mitral valve, followed by the aortic valve. These two valves are the most vulnerable due to their structural similarity to certain antigens found in streptococcus bacteria.

Why The Mitral and Aortic Valves Are Frequently Affected

When the body is infected with streptococcus bacteria, it produces antibodies to fight off the infection. However, because the structure of the mitral and aortic valves resembles that of the bacterial antigens, the immune system can mistakenly target these heart valves. This immune response leads to chronic inflammation and damage over time.

The Immune System's Role in Valve Damage

This autoimmune reaction is a key factor in the development of rheumatic heart disease. As the body continues to produce antibodies against what it perceives as foreign invaders, the valves suffer repeated injury. Eventually, this results in scarring, thickening, and narrowing of the valve leaflets, which can lead to serious complications such as stenosis or regurgitation.

Rarity of Tricuspid and Pulmonary Valve Involvement

In contrast, the tricuspid and pulmonary valves are rarely affected by rheumatic heart disease. The reason for this lies in the differences in valve structure—these valves do not share the same antigenic similarities with streptococcus bacteria as the mitral and aortic valves do. Therefore, they are less likely to be targeted by the immune system following a streptococcal infection.

Understanding this pattern of valve involvement is crucial for early diagnosis and management of rheumatic heart valve disease, especially in regions where rheumatic fever remains prevalent.