Review Question - QID 109582

A 27-year-old woman who is an immigrant from Bolivia presents to the emergency department with cough and shortness of breath. She immigrated to the United States 5 months ago and does not present with any medical records. The patient also complains of nausea and vomiting. Her temperature is 99.5°F (37.5°C), blood pressure is 90/65 mmHg, pulse is 140/min, respirations are 18/min, and oxygen saturation is 98% on room air. A cardiac exam reveals an apical murmur. A pulmonary exam reveals mild bibasilar crackles. On abdominal exam, you note increased abdominal girth without any tenderness. Neurological and musculoskeletal exams are within normal limits. Laboratory values are ordered as seen below.

Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 4,500/mm^3 with normal differential
Platelet count: 100,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.4 mEq/L
HCO3-: 24 mEq/L
BUN: 20 mg/dL
Glucose: 220 mg/dL
Creatinine: 1.1 mg/dL
Ca2+: 10.2 mg/dL
ß-hCG: 175,000 mIU/mL
AST: 12 U/L
ALT: 10 U/L

An ECG is performed as seen in Figure A. The patient is started on IV fluids. Which of the following is most likely present in this patient's past medical history?