Canadian cardiovascular society (CCS) angina grade is a classification system used to grade the severity of exertional angina. Grade and description: I: Angina with strenuous/rapid/prolonged exertion at work or recreation only; no angina with ordinary physical activity, e.g. walking, climbing stairs; II: Ordinary activity slightly limited: angina with walking/climbing stairs rapidly, walking uphill, walking or stair climbing after meals, in cold/wind, under emotional stress, during few hours after awakening, walking >2 blocks on level ground, or climbing >1 flight of stairs at normal pace and normal conditions; III: Marked limitation of ordinary physical activity: angina with walking 1-2 blocks on level ground or climbing 1 flight of stairs at normal pace and normal conditions; IV: Inability to carry on any physical activity without discomfort; anginal syndrome may be present at rest.