Table 1.4. Coronary Artery Surgery Study angina classification system.

Definitely anginal pain	Retrosternal pain due to exertion, radiating to the shoulder, neck or left arm and attenuated by rest or nitrates in <10 min
Probably anginal pain	Most of the characteristics of definite angina pain
Probably not anginal pain	Atypical pain that does not meet the criteria for anginal pain
Definitely not anginal pain	Pain uncorrelated with physical activity (suggestive of non-cardiac origin) that is unmitigated by nitrates

Source: Adapted from the National Heart Lung and Blood Institute's Coronary Artery Surgery Study.²²