Infective endocarditis can progress to an intracardiac abscess in 20% to 30% of cases, with interventricular septal abscess (IVSA) being one of the rare complications usually presenting with sepsis. We present a case of IVSA presenting with a new-onset second-degree heart block, which rapidly progressed to a complete heart block.
A 80-year-old Caucasian female with a past medical history of hypertension and hyperlipidemia presented with exertional chest pain, lightheadedness, and shortness of breath with telemetry and electrocardiogram revealing persistent Mobitz type II second degree atrioventricular block. The rest of the vitals were normal. As she was being planned for a pacemaker placement, she spiked a temperature of 103F. Blood cultures grew methicillin-sensitive Staphylococcus aureus, and appropriate antibiotics were initiated. Transthoracic echocardiogram was grossly normal. However, transesophageal echocardiogram revealed a heterogeneous extension of an echodensity from the aortic root, along the aorto-mitral cushion and into the interventricular septum, indicating an interventricular septal abscess. Her course was complicated by altered mental status, with computed tomography of the brain revealing hypodense regions in the left lentiform nucleus and anterior caudate nucleus representing acute/subacute stroke. Surgery was deferred as she was deemed a poor candidate. She succumbed to her illness on day 6 of hospitalization.
Intracardiac abscesses should be considered a possible initial differential in patients with progressive heart block despite aseptic presentation and no risk factors.

© 2023. The Author(s).