Ehrlichia Perimyocarditis: A Rare Culprit in Biventricular Systolic Heart Failure

Description of Clinical Presentation: A 23 year old female with history of Crohn’s disease on immunosuppression with upadacitinib and sulfasalazine presented with fevers, nausea and headache. She was tachycardic and hypotensive refractory to fluid resuscitation and started on vasopressors. She recently noticed a tick bite and started course of doxycycline as an outpatient which she had not completed. Inflammatory markers (CRP 37) and high sensitivity troponin I (257) were elevated. Lumbar puncture and other initial labs were unrevealing. She was started on empiric meningitis treatment and doxycycline.

Diagnostic Techniques and Their Most Important Findings: An echocardiogram revealed ejection fraction (EF) of 45-50% with moderate pericardial effusion without tamponade. Cardiac magnetic resonance imaging (CMR) noted biventricular global systolic dysfunction (LVEF 28%, RVEF 24%) with diffusely increased native myocardial T1 of 121 ms and T2 values of 71 ms with patchy late gadolinium enhancement (LGE) and ECV 45%. There was a large pericardial effusion with pericardial inflammation. She was diagnosed with perimyocarditis and started on ibuprofen and hydrocortisone. She underwent a right heart catheterization with biopsy and pericardiocentesis with removal of 300mL of seosanguinous fluid revealing acute and chronic inflammation without intracytoplasmic organisms. Right ventricular biopsy demonstrated acute and chronic lymphocytic inflammation with myocyte necrosis and interstitial fibrosis consistent with myocarditis and was negative for giant cells, granulomas, or eosinophilia; steroids were stopped. A Monospot test was positive for Epstein–Barr virus felt to be reactive. Ehrlichia chaffeensis Polymerase Chain Reaction was positive with morula seen on peripheral smear suggestive of severe Ehrlichia perimyocarditis. She was continued on treatment with doxycycline and initiated on guideline directed medical therapy for heart failure. Repeat echocardiogram showed recovery of biventricular function prior to discharge and follow up CMR one month later revealed LVEF 55% and RVEF 57% with improved native T1(135 ms), T2 (52ms) and ECV (36%) consistent with resolving perimyocarditis.

Learning Points from this Case: Human ehrlichiosis is a rare, potentially fatal disease with annual incidence of 0.08 cases/1 million in the United States and geographical prevalence in southeastern and south-central states. Perimyocarditis due to Ehrlichia is exceedingly rare with few reported cases. Pathogenesis may relate to myocardial dysfunction induced by dysregulation of the inflammatory response against the pathogen. High index of suspicion should be applied to patients with cardiac manifestations and appropriate risk factors. CMR is invaluable in reaching the appropriate diagnosis and surveillance in recovery. Treatment with doxycycline can result in successful outcomes and recovery of cardiac function in conjunction with initiation of heart failure neurohormonal blockade.

Figure 1: Cardiac MRI Imaging demonstrating evidence of perimyocarditis with Panel 1 showing increased native and post contrast T1 mapping values, Panel 2 showing patchy areas of increased T2 mapping values, and Panel 3 demonstrating patchy areas of late gadolinium enhancement.
Figure 2: Myocardial biopsy slides demonstrating mononuclear inflammation infiltrating the cardiomyocytes with focal myonecrosis. Nonspecific findings suggestive of either disseminated endothelial infection of the small vessels or secondary immune mediated mononuclear inflammatory reaction.
Figure 3: Peripheral blood smear demonstrating morula within the white blood cell’s cytoplasm- diagnostic of ehrlichia infection.