Streptococcus constellatus Left Ventricular Apical Mural Infective Endocarditis With Acute Stroke, Septic and Cardiogenic Shock.

Infective endocarditis (IE) is a severe infection of the endocardium and cardiac valves by multiple etiologic agents. Clinical presentation can be acute or subacute based on the host immunity and the causative agent's virulence. Although Streptococci are responsible for most community-acquired native valve bacterial IE, Streptococcus constellatus is an infrequent cause. S. constellatus can rarely infect prosthetic cardiac valves. A middle-aged white male with poorly controlled type 2 diabetes mellitus was transferred to our facility for suspected stroke with an initial presentation of acute encephalopathy of uncertain duration. Transthoracic echocardiogram revealed a left ventricular apical mural vegetation, and brain imaging displayed multiple white matter hypodensities indicative of numerous small strokes. Blood cultures were positive for S. constellatus. Clinical presentation was unusual with an acute encephalopathy due to multiple septic emboli and primary mural IE with high-grade bacteremia due to S. constellatus. PubMed medical literature review reveals this to be a rare clinical presentation by an uncommon etiological agent with an infrequent echocardiogram finding.