Review Question - QID 213536

A 33-year-old woman with no prior medical history is brought to the emergency department for severe bilateral lower extremity pain, which began just after completing a marathon. She also reports fatigue and brown urine. On exam, motor strength is 3/5 throughout the left lower extremity, 4/5 throughout the right lower extremity, and 5/5 in both upper extremities. The lower extremities are tender to palpation bilaterally but non-edematous and non-erythematous. Echocardiogram (ECG) is shown below (Figure A). Which of the following abnormalities is most likely to be seen in this patient?