Abstract
Bilateral multivalvular infective endocarditis (MIE) involving two or more cardiac valves of both the left and right sides of the heart is an extremely rare disease with a high mortality rate. We present a rare case of left- and right-sided MIE caused by Streptococcus mitis/oralis in a 36-year-old immunocompetent woman. The patient, with a past medical history of heart murmur since childhood, presented with left upper quadrant (LUQ) pain, fever, and chills. In the emergency department (ED), the patient's mental status deteriorated. On a physical examination, a holosystolic heart murmur was heard at the apex. The abdomen was tender in the LUQ. Neurological examination showed new right lower and upper extremity weakness. Laboratory results were significant for neutrophilic leukocytosis. The electrocardiogram (EKG) showed the right bundle branch block. Chest computed tomography (CT) of the abdomen and pelvis revealed splenomegaly with a splenic infarct. Magnetic resonance imaging (MRI) of the brain showed acute ischemic infarction of the left middle cerebral artery distribution. The patient underwent a mechanical thrombectomy. A repeat MRI of the brain showed a hemorrhagic conversion; thus, the patient was on hemicrania watch for five days. Transthoracic echocardiography (TTE) revealed left- and right-sided infective endocarditis (IE) with mobile 14 mm and 20 mm vegetations on the mitral and tricuspid valves and a left-to-right shunt through a patent foramen ovale (PFO). Blood culture grew Streptococcus mitis/oralis. Six-week antibiotic therapy was initiated. Surgical intervention for infective endocarditis was recommended, and the patient was transferred to the tertiary center for valve replacement surgery. However, the patient refused surgery despite understanding the risks and decided to return to her home country. In conclusion, bilateral multivalvular infective endocarditis is a rare and complex condition with a high burden of complications. This case underscores the importance of early diagnosis, prompt initiation of antimicrobial therapy, and timely surgical intervention to optimize outcomes.