Estimation of Level of Risk At initial presentation, the clinical history, anginal symptoms and equivalents, physical examination, ECG, renal function, and cardiac troponin measurements can be integrated into an estimation of the risk of death and nonfatal cardiac ischemic events (Table 3 and Figure 2).42,78 3.3.2.1. History: Angina Symptoms and Angina Equivalents In patients with or without known CAD, clinicians must deter- mine whether the presentation is consistent with acute isch- emia, stable ischemic heart disease, or an alternative etiology. Factors in the initial clinical history related to the likelihood of acute ischemia include age, sex, symptoms, prior history of CAD, and the number of traditional risk factors.99 105 The characteristics of angina include deep, poorly localized chest or arm pain that is reproducibly associated with exertion or emotional stress.106 Angina is relieved promptly (ie, in <5 minutes) with rest and/or short-acting nitroglycerin. Patients with NSTE-ACS may have typical or atypical anginal symp- toms, but episodes are more severe and prolonged, may occur at rest, or may be precipitated by less exertion than the patient previously experienced. Some patients have no chest pain but present solely with dyspnea or with arm, shoulder, back, jaw, neck, epigastric, or ear discomfort.107 109 Features not characteristic of myocardial ischemia include: Pleuritic pain (sharp or knifelike pain provoked by res- piration or cough); Primary or sole location of discomfort in the middle or lower abdomen; Pain localized by the tip of 1 finger, particularly at the LV apex or costochondral junction; Pain reproduced with movement or palpation of the chest wall or arms; Brief episodes of pain lasting a few seconds or less; Pain that is of maximal intensity at onset; and Pain that radiates into the lower extremities. 