Case Presentation:
An otherwise healthy, 48-year-old man from Maine presented with URI symptoms and five days of “inability to warm his feet” after a recent kayaking trip. He was afebrile and nontoxic. On exam he had mottling of the fingers and toes, and labs were notable for elevated AST, ALT, LDH, CPK, troponin, acute renal failure, and marked neutrophilia, but no cytopenias. Based on a reported history of tick exposure, he was empirically treated for Lyme disease and transferred to our hospital.
On arrival, the patient was in no distress, appeared well, but noted his cold feet, which were cool and cyanotic on exam. He denied any cardiac symptoms, however he did report a history of early heart disease in his father. Re-evaluation of his EKG showed Q-waves and signs of ischemia. A STAT echocardiogram demonstrated severe systolic dysfunction and he was transferred to the CCU where invasive monitoring demonstrated cardiogenic shock with peripheral vasoconstriction. Coronary angiography showed multi-vessel disease not amenable to PCI or CABG and he was referred for transplant. Unfortunately, his course was complicated by cardiac arrest requiring emergent ECMO, and embolic CVA after LVAD placement. All infectious studies, as well as myocardial biopsy, returned negative. Images of the patient’s feet and presenting EKG will be shown (see attached).
Discussion:
This case demonstrates a number of cognitive errors including confirmation bias and diagnostic anchoring. Due to the initial report of a tick exposure, providers prematurely concluded that he had a systemic infection, and this diagnosis became fixed. His atypical presentation for coronary artery disease lowered its likelihood on the differential for multiple subsequent providers. Once his presentation was recognized to be consistent with post-infarction inflammation and tissue hypoperfusion, the correct diagnosis was made. Unfortunately, his delay in diagnosis and extensive burden of disease led to rapid decompensation.
Conclusions:
The history and physical exam are the foundation of medical decision making. Multiple cognitive biases are usually at play when diagnostic anchoring results. Heart disease remains the number one cause of death in the United States with a small percentage of the population presenting with silent disease.
