Case 413 -- A 12 year-old boy presented with substernal chest pain

Contributed by Kenichi Tamama, MD, PhD and Mohamed A. Virji, MD, PhD
Published on line in January, 2005
PATIENT HISTORY:
12 year-old boy without significant past medical history presented with substernal chest pain. He was diagnosed to have left lower lobe pneumonia and was receiving oral antibiotics for 2 days prior to this referral. His chest pain subsided after albuterol nebulizer treatment in a local hospital, but he was found to have elevations of cardiac troponin I (cTnI) and creatine kinase (CK)-MB with ST changes on electrocardiogram (ECG), and was referred for further evaluation.
Family History
- Strong history of hypertension
- Paternal great grandfather died suddenly of heart attack at 26 years of age. His maternal great grandmother has a history of heart problems and died at 40 years of age.
Lab Results
- cTnI 20.5 ng/mL (<0.1), total CK 229 U/L (0-200), CK-MB 30 U/L (CK-MB relative index 13.1) in initial presentation
- cTnI 6.99 ng/mL (<0.1), total CK 86 U/L with CK-MB 4.7 U/L (CK-MB relative index 5.5) 12 hs after the initial laboratory results
- Na 142 mEq/L, K 4.3 mEq/L, Cl 109 mEq/L, CO2 23 mmol/L, BUN 13 mg/dL, Creatine 0.6 mg/dL, Glu 82 mg/dL
- Total Cholesterol 158 mg/dL (144-173), HDL-Cholesterol 18 mg/dL (46-61), LDL-Cholesterol 110 mg/dL (82-109), VLDL-Cholesterol 30 mg/dL (7-12), Triglycerides 185 mg/dL (46-74)
- Viral titers and blood counts: Not obtained
Chest X-ray

- There is increased air space opacity present within the left lung base (Figure 1)
It is consistent with left basilar pneumonia
Electrocardiogram:
- ST segment elevations in leads I, II, III and V6 It is consistent with myocardial ischemia/infarction involving the right coronary artery.
Echocardiogram
- Low normal LV systolic function with ejection fraction of 59%
- No pericardial fluid
- The origins of the coronary arteries in the proximal branches were normal.
- No wall motion abnormality and These echocardiogram findings are not consistent with myocardial infarction or Kawasaki disease.
In summary, 12 year-old boy presented with chest pain with elevations of troponin and CKMB, and ST changes on ECG. These findings are consistent with acute myocardial infarction. But, the diagnostic challenge was to determine if the elevations in cardiac markers for ischemic heart damage did represent myocardial infarction in this very young patient, or whether the pattern indicated other cause for the increase in the markers.
DIAGNOSIS and DISCUSSION


