Case Presentation: A 93-year-old African-American male with history of CVA, HTN, and dementia presented with a right femoral neck fracture after a same level fall. Vital signs on admission were unremarkable. Physical examination revealed a cachectic male at his baseline mental status. He was admitted and underwent uncomplicated right hemiarthroplasty. On post-operative days 3-5, patient had three medical response team evaluations called for tachycardia. Each time, patient had sustained heart rates in the 170s. Laboratory studies reviewed show normal electrolytes. Patient had no prior history of arrhythmias, structural heart disease, or heart failure. Electrocardiograms reviewed showed a narrow complex tachycardia consistent with atrioventricular nodal reentrant tachycardia. Cardiology team evaluated the patient, and he was started on amiodarone for rate control. Transthoracic echocardiogram obtained showed new vegetations on the mitral valve concerning for endocarditis. Transesophageal echocardiogram was not pursued due to patient’s underlying dementia. Blood cultures and other infectious work serologies obtained were negative. Patient was treated for six weeks with parenteral antibiotics with resolution of his mitral valve vegetation and recurrent episodes of tachycardia.

Discussion: Supraventricular arrhythmias presenting as infective endocarditis is rare. To our review, only one other case is reported. In both cases, the patients were older men with mitral valve vegetations leading to atrioventricular nodal reentrant tachycardia. Unlike the prior case, our patient did not die from progressive valvular dysfunction due to infective endocarditis.

Conclusions: Unexplained recurrent supraventricular tachycardia can be a sign of underlying infective endocarditis. Transthoracic echocardiogram can identify new vegetations in at-risk patients. Prompt medical therapy can reduce risk for persistent arrhythmias and valvular complications.