A 37-year-old man with type 1 diabetes had a 2-day history of worsening nausea, vomiting, malaise, and abdominal pain that began shortly after intentionally stopping his insulin regimen. He denied chest pain, shortness of breath, and recent illness. Initial vital signs were significant for tachycardia and tachypnea, and results of the physical exam were normal except for diffuse abdominal tenderness. Initial laboratory testing revealed a serum pH of 7.09, a blood glucose level of 850 mg/dL, an anion gap of 50 mEq/L (serum bicarbonate level of 6 mEq/L), and a serum troponin I (TnI) concentration of 0.33 ng/mL (normal range, 0-0.5 ng/mL). There was no evidence of ischemia on ECG. The urine drug screen result was negative for illicit substances, including cocaine. Other relevant laboratory values are noted in Table 1.
Table 1—Laboratory Values During Two Admissions for Diabetic Ketoacidosis*
His past medical history included a prior ST-elevation myocardial infarction (MI) 16 months earlier during a prior episode of diabetic ketoacidosis (DKA), hypertension, hyperlipidemia and poorly controlled type 1 diabetes (hemoglobin A1c = 12.2% on prior admission, four prior hospitalizations for DKA). The patient never reported chest pain during his prior admission for MI, but ST segment elevation was observed in the inferior and precordial leads (Fig 1). Transthoracic echocardiogram showed an ejection fraction of 40% with mild global hypokinesis, and cardiac catheterization revealed normal coronary arteries during that admission.
Figure 1. ECG from 2006 admission for DKA (corresponding troponin I level approximately 4 ng/mL).
Over the next 2 days of treatment, the patient’s anion gap and hyperglycemia resolved, but his TnI concentration increased to 21.3 ng/mL. Serial ECGs remained unremarkable (Fig 2), although the patient began to complain of intermittent chest discomfort on hospital day three. Transthoracic echocardiogram findings were unchanged from the previous findings, and repeat cardiac catheterization showed no significant coronary artery disease.
Figure 2. ECG from 2007 admission for DKA (corresponding troponin I level approximately 20 ng/mL).
What is the diagnosis?
Submitted by:
CPT Leslie A. Jette, MC, USA
CPT Jason D. Heiner, MC, USA
MAJ Jeremy C. Pamplin, MD
Departments of Medicine and Emergency Medicine
Madigan Army Medical Center
Tacoma, WA
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