Introduction: Lyme disease and anaplasmosis often present with nonspecific symptoms. We present a case of Lyme and Anaplasma coinfection manifesting as atrial fibrillation, cardiogenic shock, severe thrombocytopenia, and multiorgan failure.
Description: A 70-year-old woman with newly diagnosed atrial fibrillation (not on rate/rhythm control therapy), presented with fever, lethargy, tachycardia and hypotension. Labs showed leukocytosis, mild thrombocytopenia, and lactic acidosis. CT revealed acute cholecystitis and pancreatitis. She was treated for presumed septic shock with norepinephrine and vasopressin and underwent percutaneous cholecystostomy. Despite intervention, she developed worsening shock and atrial fibrillation with rapid ventricular response (RVR). Echocardiography showed severe biventricular dysfunction (EF < 20%). Left heart catheterization revealed normal coronary arteries, while right heart catheter was consistent with cardiogenic shock. The etiology of her cardiogenic shock was attributed to new-onset atrial fibrillation with RVR and stress-induced/tachycardia-mediated cardiomyopathy. She required escalating support with multiple vasopressors and inotropes, including norepinephrine, epinephrine, and dobutamine. Her hospital course was further complicated by worsening cardiogenic shock and multiorgan dysfunction, including ischemic hepatitis, acute renal failure requiring CRRT, and severe thrombocytopenia. Peripheral smear revealed morulae within neutrophils, and testing confirmed Borrelia burgdorferi and Anaplasma phagocytophilum coinfection. She was started on intravenous doxycycline with rapid clinical improvement—vasopressors were weaned, EF normalized, and organ function recovered, though she remained dialysis-dependent but with improving urine output. She completed her course of doxycycline and was subsequently discharged to a rehabilitation center.
Discussion: This case highlights an atypical and severe presentation of tick-borne coinfection lacking hallmark features. The initial misdiagnosis delayed treatment, but the patient improved rapidly after doxycycline initiation—underscoring the importance of considering vector-borne illnesses in cases of unexplained shock, especially in endemic regions.
