Which of the following conditions causes angina pectoris?

Angina pectoris is primarily caused by ischemia, which refers to insufficient blood flow to the heart muscle, resulting in a lack of oxygen. When the heart muscle does not receive enough oxygenated blood, it can lead to pain or discomfort in the chest, typically experienced as pressure or squeezing. This condition often arises due to underlying coronary artery disease where narrowed arteries restrict blood flow during increased demands, such as physical exertion or emotional stress.

While excessive exercise can be a trigger for angina in individuals with coronary artery disease, it does not directly cause the condition. High blood pressure can contribute to heart issues in the long term but is not a direct cause of angina pectoris. Similarly, valve malformation may affect heart function but does not directly lead to angina without the presence of oxygen deprivation to the heart muscle. Thus, ischemia or lack of oxygen is the essential factor leading to angina pectoris.