**4. Clinical features**

Right-sided infective endocarditis usually presents with fever, persistent bacteraemia and septic emboli to the lungs. Initial presentation may comprise haemoptysis, cough or chest pain. Peripheral embolization must alert one to the presence of concomitant left-sided endocarditis or a shunt. Right heart failure is a result of both pressure and volume overload from pulmonary hypertension or organic tricuspid regurgitation or rarely obstruction of the tricuspid orifice by a vegetation [17, 18].

Pulmonary septic emboli may be complicated by pulmonary infarction, abscess, pneumothorax, and purulent pulmonary effusion [17] (**Figures 1** and **2**).

It is important to note that patients with RSIE do not always have an audible murmur of tricuspid regurgitation [13]. Other features unique to this group of patients with IE are the presence of co-infections with HIV, hepatitis C and hepatitis B infections, which complicate their clinical management and adversely affect their outcomes. A high degree of suspicion of IE must be maintained in IVDA as their clinical assessment can be quite challenging, especially in those who do not manifest the classic clinical features.

Additionally, the sensitivity and specificity of the modified Duke's criteria in right-sided endocarditis has not been studied. Inclusion of septic pulmonary infarcts as a minor criteria in the modified Duke's criteria may therefore be inappropriate [19].

#### **Figure 1.**

*An anterior-posterior chest X-ray showing increased cardiothoracic index with areas of alveolar opacification involving both lung fields likely representing septic embolization and abscess formation in the lungs.* 

#### **Figure 2.**

*Multiple areas of consolidation suggestive of infarction and dilated right heart chambers on a CT scan of the chest of a patient with history of right-sided infective endocarditis due to intravenous drug abuse.* 
