Critical Care Medicine-Neurologic Disorders>>>>>Imaging and Diagnostic Modalities
Question 1#

A 35-year-old-patient with no past medical history comes to the Emergency Department with complaints of several days of fatigue and constant chest pain that is substernal but not radiating, “sharp,” and worsened with inspiration, but seems to improve with sitting forward. He has noticed a 10 lbs unintentional weight gain over the past 2 weeks and significant fatigue. He reports only local travel in the last 2 months and otherwise had a “cold a few weeks ago.” His family history is negative for ischemic heart disease, and he is a nonsmoker and has never used any substances such as cocaine, marijuana, or amphetamines. Examination in the Emergency Department reveals tachycardic heart without gallop or rub, and symmetric 2+ pitting edema to his calves. Initial laboratory test results are notable for an elevated troponin-T and the following ECG:

Which of the following is the BEST imaging modality to diagnose the etiology of his underlying disease?

A. CT Coronary Angiography
B. Cardiac MRI
C. Transesophageal Echocardiogram
D. Cardiac catheterization with ventriculography

Correct Answer is B

Comment:

Correct Answer: B

The presentation is most consistent with viral myocarditis. Diagnosis of myocarditis is multimodal, though the gold standard is considered to be endomyocardial biopsy (EMBx). However, because of the morbidity associated with an EMBx, the diagnosis is typically a combination of noninvasive diagnostic imaging, serology, and clinical presentation. The patient is a young male with no risk factors for premature coronary artery disease and his clinical presentation is more consistent with a viral myopericarditis, with low concern for coronary ischemia, and thus would be a good candidate for Cardiac MRI. CT Coronary Angiography would not be the most appropriate test given low concern for coronary artery disease and a clinical picture highly consistent with viral myocarditis. Echocardiography would definitely provide information about cardiac function, but Cardiac MRI is a superior test for this scenario because it can provide ancillary information about findings suggestive of myocarditis such as myocardial edema and gadolinium enhancement. Transesophageal echocardiography as a test is rarely indicated in myocarditis. Invasive ventriculography can be performed with a left heart catheterization but should be reserved for when left ventricular function is unknown, and there is an indication for invasive catheterization. Thus, cardiac MRI would be the best first choice. 

References:

  1. Friedrich MG, Sechtem U, Schulz-Menger J, et al. Cardiovascular magnetic resonance in myocarditis: a JACC white paper. J Am Coll Cardiol. 2009;53(17):1475-1487.
  2. Goenka AH, Flamm SD. Cardiac magnetic resonance imaging for the investigation of cardiovascular diss. Part 1: current applications. Tex Heart Inst J. 2014;41(1):7-20.