Author: Dylan Luyten, MD Educational Pearls: While certain aspects of the history, exam, and EKG may increase likelihood of ACS, there is no one element that performs well on its own  Elements of the history have been found to have different likelihood ratios, which can increase or decrease the probability of a patient having ACS Likelihood ratios greater than one increase the chance of the patient having the disease. Ratios less than one decrease it   Bilateral arm radiation is one of very few historical features that increases the likelihood of ACS ST depressions are one of the few EKG findings with a high LR for ACS Scoring systems such as the HEART score can be useful to risk stratify your patients   References Fanaroff AC, Rymer JA, Goldstein SA, Simel DL, Newby LK. Does This Patient With Chest Pain Have Acute Coronary Syndrome?: The Rational Clinical Examination Systematic Review. JAMA. 2015 Nov 10;314(18):1955-65. doi: 10.1001/jama.2015.12735. Review. PubMed PMID: 26547467. Backus BE, Six AJ, Kelder JC, Bosschaert MA, Mast EG, Mosterd A, Veldkamp RF, Wardeh AJ, Tio R, Braam R, Monnink SH, van Tooren R, Mast TP, van den Akker F, Cramer MJ, Poldervaart JM, Hoes AW, Doevendans PA. A prospective validation of the HEART score for chest pain patients at the emergency department. Int J Cardiol. 2013 Oct 3;168(3):2153-8. doi: 10.1016/j.ijcard.2013.01.255. Epub 2013 Mar 7. PubMed PMID: 23465250.   From CarePoint PA Academy, 2019