In cases of IV drug abuse, which valve is most commonly affected by infective endocarditis?

Infective endocarditis in intravenous drug users commonly affects the tricuspid valve due to the route of drug administration and the associated hemodynamics. When drugs are injected, particularly through non-sterile techniques, bacteria can enter the bloodstream, leading to bacteremia. This condition frequently results in the colonization of heart valves, and in the case of IV drug users, the right-sided heart valves, particularly the tricuspid valve, are the most susceptible.

The tricuspid valve is directly connected to venous circulation, making it more exposed to infectious agents introduced via dirty needles. Additionally, the turbulent blood flow associated with injection practices can facilitate the adherence of bacteria to heart valves. This preferential infection of the tricuspid valve can lead to complications such as septic pulmonary emboli since the infected material can easily break off and travel into the pulmonary circulation.

Other valves, like the aortic and mitral valves, are more commonly affected in patients with underlying heart disease or in cases of endocarditis linked to other sources of bacteremia, such as dental procedures or skin infections, rather than in IV drug users. Thus, the tricuspid valve's unique position in relation to venous access and its exposure during IV drug use makes