Q. A 61-year-old Indian man comes to the clinic because of a fever of 10 days. The patient immigrated to the United States 10 years ago, and his medical history is unknown. The patient's vital signs show mild tachycardia and a low-grade fever. Cardiac auscultation reveals an accentuated first heart sound with a holosystolic murmur radiating to the axilla. Echocardiography confirms the presence of a cardiac vegetation. Consecutive blood cultures grow Enterococcus faecalis. Which of the following is an expected additional finding in this patient's history?