* *Colors correspond to the class of recommendations in the ACCF/AHA Table 1. The algorithms do not represent a comprehensive list of recommenda- tions (see text for all recommendations). CABG indicates coronary artery bypass graft; PCI, percutaneous coronary intervention. Table 5. Clinical Classification of Chest Pain Typical angina (definite) 1) Substernal chest discomfort with a characteristic quality and duration that is 2) provoked by exertion or emotional stress and 3) relieved by rest or nitroglycerin Atypical angina (probable) Meets 2 of the above characteristics Noncardiac chest pain Meets 1 or none of the typical anginal characteristics Adapted from Braunwald et al.6 Fihn et al Stable Ischemic Heart Disease: Full Text e369 (AV) block, or ventricular tachyarrhythmia65; or left ventric- ular (LV) hypertrophy.62,66 2.1.5. Differential Diagnosis Although the symptoms of some patients might be consistent with a very high probability of IHD, in others, the etiology might be less certain, and alternative diagnoses should be considered (Table 7). However, even when angina seems likely to be related to IHD, other coexisting conditions can precipitate symptoms by inducing or exacerbating myocardial ischemia, by either increased myocardial oxygen demand or decreased myocardial oxygen supply (Table 8). When severe, these conditions can cause angina in the absence of signifi- cant anatomic coronary obstruction. Chest pain in women is less often due to IHD than in men, even when the pain is typical. Nevertheless, pain in women can be related to vascular dysfunction in the absence of epicardial CAD. Entities that cause increased oxygen demand include hyper- thermia (particularly if accompanied by volume contrac- tion),67 hyperthyroidism, and cocaine or methamphetamine abuse. Sympathomimetic toxicity, due, for example, to co- caine intoxication, not only increases myocardial oxygen demand but also induces coronary vasospasm and can cause infarction in young patients. 