Discussion
According to previous studies, unrepaired VSD is the most common congenital abnormality associated with the highest risk of infective endocarditis(1), followed by ventricular outflow tract obstruction(2). Both these conditions were present in this patient. Berglund et al. demonstrated that a small and unrepaired VSD could increase the incidence of IE more than 20 times compared with the general population (3).
Based on European Society of Cardiology guidelines, diagnosing right-sided endocarditis is more challenging than the left side due to the lower sensitivity of duke criteria (4), as our patient was diagnosed with right-sided endocarditis with a remarkable diagnostic delay.
It has been shown that renal infarcts and non-immune complex-mediated glomerulonephritis are the most common renal lesions in right-sided IE by renal biopsy or necropsy examination. Septic embolism was the cause of renal infarcts in more than half of the patients (5).
A study in France showed the existence of septic pulmonary emboli (SPE) in up to 70% of right-sided IE(6). Diagnosing SPE can be challenging due to nonspecific presentation and can remain unrecognized.
Subacute bacterial endocarditis (SBE) and ANCA-associated systemic small vessel vasculitis have overlapping clinical manifestations. Awareness of false positive ANCA tests in SBE and possible endocardial involvement in idiopathic ANCA-associated vasculitis is important due to different management(7).
Leukocytoclastic vasculitis can be a rare presentation of IE. A retrospective study of 138 biopsy-proven cutaneous leukocytoclastic vasculitis patients showed bacterial infection as the underlying cause in 4 (2.9%), three diagnosed with IE(8).
In conclusion, IE has a wide variety of presentations, imitating connective tissue disorders and vasculitis, so even subtle symptoms should be considered seriously, especially in patients at high risk for endocarditis.