emDocs - June 15, 2016 - Author: Simon E - Edited by: Koyfman A and Alerhand S
"What Can We Conclude?
- Cardiac troponins are sensitive in terms of locale – they are found only in the myocardium. Troponin elevation is NOT specific for myocardial infarction or coronary artery pathology. Cardiology literature has identified numerous etiologies of troponin elevation in the absence of coronary angiographic findings. Case reports in the pediatric population have also demonstrated the same.
- Current research regarding the utilization of troponin levels in the evaluation and management of SVT is limited to small cohort studies (low n), case series, and case reports. One Best Evidence Topic Summary published in the Emergency Medicine Journal in 2010 recommends against the routine use of troponin levels in the setting of uncomplicated SVT (a presentation undefined in the BET summary), due to the potential for unnecessary testing and treatments.
- A study out of Johns Hopkins has demonstrated an increased risk of death, MI, and CV re-admission in patients requiring hospitalization following an ED presentation of SVT with elevated troponin (these individuals were more likely to have numerous medical co-morbidities [CAD, DM, COPD, CrCl <60ml/min, etc.]).
Bottom Line
Given this review and the aforementioned findings, it is reasonable to infer that the decision to send a troponin should be based on a thorough H&P – if the history is concerning, anginal equivalents are present, there are cardiac risk factors, major medical comorbidities exist, or there are findings on physical exam concerning for cardiac pathology (new murmurs, signs/symptoms of new onset CHF, etc.), a troponin should be sent.
Is troponin elevation in the setting of SVT significant? In the appropriate clinical setting, yes, it can be."