Which valve is the most commonly affected in infective endocarditis?

The mitral valve is the most commonly affected valve in infective endocarditis, particularly in cases where the condition occurs in individuals with pre-existing heart conditions, such as rheumatic heart disease or mitral valve prolapse. In these instances, the abnormal valve structure creates a conducive environment for bacterial colonization, leading to infection.

In general, the left-sided heart valves, specifically the mitral and aortic valves, are frequently involved due to their higher pressure environment compared to the right-sided valves. The mitral valve is particularly susceptible because of its anatomy and positioning. During infective endocarditis, bacteria can enter the bloodstream, either from dental procedures or through skin and mucosal breaches, and settle on damaged or prosthetic valves. Once attached, they can proliferate and form vegetations, which is characteristic of the disease.

To sum up, the mitral valve's common involvement in infective endocarditis is attributed to its anatomical and physiological predispositions, alongside the typical risk factors associated with this infection.