Post-infectious Myocarditis: A Rare Complication of Campylobacter Gastroenteritis

Acute myocarditis involves inflammatory injury to the myocardium and may develop in association with diverse infectious or non-infectious triggers. Campylobacter jejuni (C. jejuni), a leading cause of bacterial gastroenteritis worldwide, is rarely associated with extraintestinal cardiac manifestations. This report describes a case of C. jejuni-associated myocarditis in a 19-year-old male patient who presented with severe central chest pain, diaphoresis, and fever three days following an episode of acute gastroenteritis. Initial investigations revealed significantly elevated cardiac biomarkers and preserved renal function. Stool polymerase chain reaction confirmed C. jejuni infection. Transthoracic echocardiography demonstrated a reduction in left ventricular (LV) systolic function with an ejection fraction (EF) of 43% and global hypokinesis. Cardiac magnetic resonance imaging (MRI) confirmed the diagnosis, showing widespread edema and late gadolinium enhancement consistent with severe acute myocarditis. The patient was managed conservatively regarding the bacterial infection but received aggressive cardiac support. Treatment included anti-inflammatory therapy with colchicine and ibuprofen, alongside the initiation of guideline-directed medical therapy for heart failure, including bisoprolol, dapagliflozin, eplerenone, and ramipril. The patient showed rapid clinical improvement and was discharged after six days. Follow-up imaging at two months demonstrated normalization of cardiac function with an LVEF of 58%, and cMRI at three months confirmed resolution of the acute inflammation. This case highlights the necessity of considering myocarditis in young patients presenting with chest pain following gastrointestinal infections. It further illustrates the potential benefit of early initiation of the "four pillars" of heart failure therapy in recovering myocardial function in bacterial myocarditis.