Which class of angina pectoris is characterized by pain only with strenuous activity?

The correct classification of angina pectoris that is characterized by pain only with strenuous activity is Class I. In this classification, episodes of angina occur only with intense physical exertion that goes beyond typical daily activities. Individuals in this class are generally able to engage in normal activities without experiencing angina, and the pain is typically resolvable with rest or the use of nitroglycerin.

This classification system, known as the Canadian Cardiovascular Society (CCS) grading system, helps in understanding the severity and impact of angina on a patient's lifestyle. Class II would involve angina with moderate exertion, while Class III occurs with minimal exertion. Class IV, on the other hand, is characterized by angina at rest or with any physical activity, indicating a much more severe limitation in activity due to heart-related pain.