Complete Atrioventricular Block Revealing Extensive Periannular Destruction in Fulminant Pneumococcal Endocarditis: A Case Report

Streptococcus pneumoniae infective endocarditis is a rare but highly aggressive infection characterized by rapid valvular destruction, extensive periannular complications, and substantial mortality.We report the case of a previously healthy 25-year-old woman presenting with fever, profound asthenia, and complete atrioventricular block with a ventricular escape rhythm of 40 beats/min.Despite initially preserved blood pressure and left ventricular ejection fraction (62%), clinical signs of peripheral hypoperfusion were present.Urgent transthoracic and transesophageal echocardiography revealed extensive aortic valve destruction with severe aortic regurgitation, concomitant mitral valve involvement, and a large aortic root abscess (45 × 27 mm) extending toward the interatrial septum, with an additional vegetation identified in the right atrium.Blood cultures were obtained, and empirical intravenous antibiotic therapy was promptly initiated.Emergency cardiac surgery with planned intraoperative epicardial pacing was indicated.However, approximately one hour after cardiac intensive care unit admission, the patient developed abrupt profound hypotension followed almost immediately by cardiac arrest with documented asystole.Despite advanced resuscitative efforts, she died approximately two hours after admission, before definitive intervention could be performed.Blood cultures subsequently identified S. pneumoniae, with microbiological confirmation becoming available only after death.This case highlights complete atrioventricular block as a critical warning sign of extensive periannular infection and demonstrates that preserved left ventricular systolic function and initially maintained blood pressure do not exclude impending cardiovascular collapse.Early recognition, immediate multidisciplinary coordination, and expedited surgical management are essential, as the therapeutic window in fulminant pneumococcal endocarditis may be exceptionally narrow.