急性感染性心內膜炎常伴隨心臟結構組織的損傷及侵犯心臟外其他結構，若未接受適當的治療，病情會在數週內進展到死亡。在臨床上，僧帽瓣心內月莫炎合併傳導異常個案極為罕見，且死亡率高。心內膜炎引發急性主動脈瓣閉鎖不全或急性僧帽瓣閉鎖不全合併失償性心臟衰竭時，需建議接受緊急外科手術治療。我們報告一位八十二歲的男性個案伴有香燒、頭暈及完全房室結傳導阻斷。以暫時性人工節律器來治療完全房室結傳導阻斷。最初的胸前心臟超音波檢查顯示未發現明顯的贅生物及正常的左心室收縮功能。血液培養報告顯示，對oxacillin敏感的金黃色葡萄球菌菌種。在住院中，患者出現急性肺水腫合併急性心因性休克。追蹤胸前心臟超音波檢查發現有大的贅生物附著在前葉僧帽瓣合併瓣膜穿孔，造成僧帽瓣嚴重的血液逆流，立即接受緊急外科手術切除僧帽瓣及置換人工瓣膜。經成功的手術治療後病人得以存活。

Acute infective endocarditis is commonly associated with damage to cardiac structures, seeding of vegetation to extracardiac sites, and progression to death within weeks if left untreated. Conduction abnormalities associated with mitral valve endocarditis are extremely rare and associated with a high mortality. Emergent surgery is recommended for acute aortic or mitral regurgitation with decompensated heart failure. We report a 82-year-old man presented with fever, dizziness and complete heart block (CHB). Temporary pacing was instituted for CHB. Initial transthoracic echocardiography (TTE) showed adequate left ventricular (LV) systolic function without evidence of vegetation. Blood culture was positive for oxacillin-sensitive Staphylococcus aureus. Acute pulmonary edema with cardiogenic shock developed during admission. Follow-up TTE revealed a large vegetation over the anterior mitral leaflet (AML) of the mitral valve with leaflets perforation and severe mitral regurgitation (MR). Emergency surgical resection of the mitral leaflets with mitral valve replacement was performed. The patient survived after successful surgical intervention.