The situation is further compounded by atypical presentations of myocardial infarction in diabetics, elderly patients and women ( Canto et al., 2000 Deedwania & Carbajal, 1991 Kyker & Limacher, 2002). Another factor needing consideration is that a significant proportion of patients with chest pain may have nonischemic ST elevation (NISTE) ( Birnbaum, 2007 Brady, Perron, Martin, Beagle, & Aufderheide, 2001 Otto & Aufderheide, 1994 Wang, Asinger, & Marriott, 2003). A reasonable assumption would be that if criteria by Thygesen et al are used, reported prevalence of STEMI would be lower. Different cutoffs in interpretation of STE create ambiguity in the mind of ECG interpreters. They recommend STE at J point of ≥ 0.2 mV in men and ≥ 0.15 mV in women in leads V2- V3 and/or ≥ 0.1 mV in all other leads. Thygesen et al, in their expert consensus document recommend different cutoffs for men and women in leads V2- V3 ( Thygesen et al., 2007).

The American College of Cardiology/American Heart Association (ACC/AHA) guidelines for STEMI recommend immediate reperfusion therapy in patients presenting within 12 hours of the onset of symptoms compatible with myocardial infarction (even if resolved) and concomitant STE in 2 or more adjacent leads (> 0.1 mV at J point) ( Antman, et al., 2004). Patients diagnosed with acute STEMI are triaged to receive urgent reperfusion therapy with either primary percutaneous coronary intervention (pPCI) or thrombolytic therapy and those judged not to have ST elevation receive conservative treatment early on ( Antman et al., 2004). The electrocardiogram (ECG) plays an important part in appropriate management of patients presenting with chest pain. More studies need to be done to delineate the criteria to clearly distinguish between ischemic and non ischemic ST elevation. The ability of clinicians to distinguish between ischemic and non ischemic STE varies widely and is affected by prevalence of such changes in patient population.

However, patients with benign STE at baseline (left ventricular hypertrophy, early repolarization pattern) may have ongoing ischemia and present with Non-ST elevation myocardial infarction (NSTEMI) or even STEMI superimposed on the benign pattern. Benign patterns can be easy to find in some cases. Since many patients presenting with ischemic symptoms may have ST elevation (STE) at baseline, not all STE signify transmural ischemia. The American College of Cardiology / American Heart Association guidelines recommend triage decisions are made within 10 minutes of performing initial electrocardiogram (ECG). Benefits of early reperfusion in patients presenting with acute ST elevation myocardial infarction (STEMI) are well known.

Ivcd vs lbbb