Frequency of Acute Coronary Syndrome in Patients with Normal Electrocardiogram Performed during Presence or Absence of Chest Pain

The presences of chest pain during EKG does not improve its negative predictive value.

The authors detail the findings of 387 consecutive patients with normal electrocardiograms admitted for a chief complaint of chest pain. The authors report that 17% (67/387) of patients had acute coronary syndrome ACS). However, the authors define ACS as:

• Unstable angina. Either:
  
  
  • 70% stenosis (38 patients)
  • positive stress test (1 patient)
• NSTEMI.
  
  
  • Positive troponin (28 patients)

The definition of unstable angina is unusual, differs from the definitions of the American Heart Association, and may include patients without acute ischemia who have a stable stenosis. Focusing on the patients with NSTEMI, the authors found:

• Among 261 patients with electrocardiogram taken during pain, 18 (7%) had NSTEMI.
  
• Among 126 patients with electrocardiogram not taken during pain, 10 (8%) had NSTEMI.
  

This study independently confirms the findings of an earlier study (PMID 16973638) that the presence of chest pain during a normal electrocardiogram does not adequately exclude NSTEMI among a group of patient that physicians chose to admit the hospital and had a 7% prevalence of NSTEMI.

This does not mean the electrocardiogram cannot help exclude acute coronary syndrome, but means that whether the electrocardiogram is taken during pain is not important.

This does not mean the electrocardiogram cannot exclude acute coronary syndrome in patients at lower risk such as those with unusual pain and no history of ischemic heart disease (PMID 3970650).

This has been added to http://en.citizendium.org/wiki/Acute_coronary_syndrome#Electrocardiogram

Citation:

Turnipseed, S., Trythall, W., Diercks, D., Laurin, E., Kirk, J., Smith, D., Main, D., & Amsterdam, E. (2009). Frequency of Acute Coronary Syndrome in Patients with Normal Electrocardiogram Performed during Presence or Absence of Chest Pain Academic Emergency Medicine, 16 (6), 495-499 DOI: 10.1111/j.1553-2712.2009.00420.x