New Mitral Regurgitation Unveiling Infective Endocarditis in an Adolescent With Mitral Valve Prolapse

Background: Infective endocarditis (IE) is a potentially life-threatening condition, possibly occurring in overlap with preexisting structural cardiac abnormalities. The Duke Criteria represent a cornerstone in the diagnosis of IE, and the detection of new regurgitation represents a major criterion that may be overlooked. Case Summary: We present a case of a 14-year-old girl with mitral valve prolapse (MVP) who developed IE. Despite initial negative echocardiographic findings for vegetations, thorough analysis revealed the presence of a new regurgitation jet at P3 scallop, thereby distinguishing it from the mild preexisting central mitral regurgitation. Discussion: This case highlights the diagnostic challenges of IE when vegetations are absent on echocardiography. In this setting, recognizing a new jet from a preexisting regurgitation is crucial in making the diagnosis. Take-Home Messages: Echocardiography represents the cornerstone for diagnosing IE. Indeed, in patients with MVP, careful assessment of new regurgitation, even in the absence of visible vegetations, should raise suspicion for IE.