A 29-Year-Old Black Male Presents to the Emergency Department with Chest Pain
A 29-year-old black male presents to the emergency department with chest pain. The symptoms were described as an acute onset of moderate substernal tightness radiating to the upper back. There was associated dyspnea, but no nausea, vomiting, or diarrhea. His symptoms were considered atypical in that they were exacerbated by stretching, deep breathing, and movement. The symptoms were different from his prior sickle cell pain crises. As there was no relief with self-administered Percocet at home, he came to the emergency department.
Social: Smokes one pack per day; no illicit drug use
Family history: Negative for premature coronary disease
Physical exam: Blood pressure 126/60 mm Hg, pulse 87 bpm, respirations 16, afebrile; oxygen saturation 99% on 2 L supplemental oxygen
Head, ears, eyes, nose, throat (HEENT): Mild scleral icterus
Heart: Regular rate and rhythm, 1/6 systolic ejection murmur at left upper sternal border; no rub or gallop
Extremities: No edema
ECG: Normal sinus rhythm, without ischemic changes
Laboratory values: Hemoglobin 8.0, white blood cell count 20.2K, platelets normal, blood urea nitrogen/creatinine 6/0.8
An echocardiogram demonstrated a mid and distal inferior wall motion abnormality with mild hypokinesia with preserved systolic function. No significant valvular abnormalities were observed, and right ventricular (RV) function was normal.
Based on the initial presentation and elevated cardiac markers, the patient was treated for acute coronary syndrome. Enoxaparin, aspirin, intravenous nitroglycerin, and metoprolol were initiated, with subsequent symptom resolution. The next day, a coronary angiography was performed, which showed normal coronary arteries. A left ventriculogram showed distal inferior hypokinesis.
Which of the following is the most likely cause for the patient's troponin elevations?