(694) Myopericarditis in a Pediatric Patient With Typical Hemolytic Uremic Syndrome

Introduction: Hemolytic uremic syndrome (HUS) due to Shiga toxin-producing Escherichia coli (E. coli) is a known cause of pediatric acute kidney injury (AKI). Common signs of HUS include microangiopathic hemolytic anemia, thrombocytopenia, and uremia. Extrarenal sequelae can occur including neurologic, pancreatic, and pulmonary disease [1]. Cardiac complications in HUS are rare (6.1 %) [2] with evidence limited to case reports.

Description: Four-year-old previously healthy female presented with bloody diarrhea, fever, tachycardia, hemolytic anemia, and renal failure. Stool pathogen polymerase chain reaction (PCR) testing revealed E coli O157:H7 infection and she was diagnosed with typical HUS. She required hemodialysis because she was unresponsive to intravenous fluid resuscitation and diuretics. Patient developed profound bloody diarrhea leading to hemorrhagic shock requiring blood products.

After transition off hemodialysis, she acutely decompensated on hospital day (HD) 10 with worsening tachycardia, tachypnea, and acute hypoxic respiratory failure. Work up was notable for electrocardiograms with diffusely flattened T waves. Transthoracic echocardiogram showed a moderate pericardial effusion, moderate mitral valve regurgitation, depressed left ventricular systolic function (EF 46%), abnormal diastolic function, and biatrial dilation. She had elevated central venous pressures (15-20 mmHg) and cardiac biomarkers with a peak troponin of 71 ng/L and peak NT-proBNP of 60,565 pg/mL. She was diagnosed with myopericarditis and treated with colchicine and NSAIDs, infusions of clevidipine and nicardipine (6 days), milrinone (7 days), and furosemide (3 days). Evaluation prior to discharge on HD 21 revealed resolved pericardial effusion, normal biventricular function, and down-trending cardiac biomarkers.

Discussion: HUS is an infectious and inflammatory process primarily affecting the kidneys, however, extra-renal manifestations can occur. Cardiac complications are rare with mortality as high as 19.5% [2,3]. The most common cardiac conditions include pericardial disease (42.8%), congestive heart failure (19.3%) and myocarditis (14.2%) [1]. Cardiovascular sequelae must be considered in patients with persistent tachycardia and hemodynamic instability despite adequate volume resuscitation.