Acute Myocarditis Associated with Escherichia coli Bacteremia Secondary to Complicated Cholecystitis: A Case Report of Diagnostic Challenges Beyond Sepsis-Related Myocardial Injury

Acute myocardial injury during sepsis is common, but distinguishing sepsis-related myocardial injury, type 2 myocardial infarction, septic cardiomyopathy, and inflammatory myocarditis can be difficult. We report the case of a 46-year-old man who presented with epigastric and retrosternal pain, dyspnea, fever, electrocardiographic abnormalities, and marked high-sensitivity troponin elevation. Initial management included cardiac monitoring and treatment for suspected non-ST-segment elevation acute coronary syndrome with antiplatelet therapy, anticoagulation, and high-intensity statin therapy, while an infectious and inflammatory cause of myocardial injury was also considered. Transthoracic echocardiography showed a normal-sized left ventricle with mildly reduced systolic function, a left ventricular ejection fraction of 48%, reduced global longitudinal strain (-15%), grade I diastolic dysfunction, and mild hypokinesia. Blood cultures and a molecular sepsis panel identified Escherichia coli. Abdominal imaging and surgery confirmed complicated calculous cholecystitis with pyocholecyst, liquefactive necrosis of the gallbladder wall, and an adjacent abscess. Coronary angiography showed no significant obstructive epicardial coronary disease. Cardiac magnetic resonance demonstrated myocardial edema and subepicardial/mid-myocardial late gadolinium enhancement in a nonischemic distribution, supporting acute myocarditis. The patient improved after broad-spectrum antibiotic therapy, cardiac-directed initial management, and laparoscopic cholecystectomy with abscess drainage. This case broadens the clinical contexts of E. coli-associated myocardial inflammation and highlights the value of cardiac magnetic resonance when myocardial injury during Gram-negative bacteremia cannot be explained solely by coronary disease presenting as acute coronary syndrome, type 2 myocardial infarction, or sepsis-related mechanisms, including sepsis-associated cardiomyopathy or septic myocarditis. This distinction is especially relevant when clinical, electrocardiographic, and biomarker findings overlap in patients without classical cardiovascular risk factors.