Why does angina occur at rest?

The main causes of angina attacks at rest include increased myocardial oxygen demand, oxygen supply and demand imbalance, endothelial dysfunction, platelet aggregation and other factors. Some angina attacks also occur at rest, mainly due to the following reasons. Increased myocardial oxygen demand: Heart rate is usually slower and blood pressure is lower at rest, but in angina patients, myocardial oxygen demand does not decrease correspondingly, and may even be higher than during daily activities, resulting in insufficient blood supply to the myocardium, causing angina pectoris. Oxygen supply and demand imbalance: In patients with exertional angina pectoris, the supply and demand of myocardial oxygen can be balanced at rest, but when variant angina occurs, coronary spasm can lead to a significant increase in myocardial oxygen demand, and the imbalance between oxygen supply and demand, thus causing angina pectoris. Endothelial dysfunction: Endothelial dysfunction can lead to endothelium-dependent vasodilation dysfunction, so that vasodilation and platelet aggregation are inhibited, resulting in angina pectoris. Platelet aggregation: Platelet aggregation can lead to coronary artery stenosis or occlusion, resulting in angina pectoris. Other factors: anemia, infection, hyperthyroidism, etc., can also increase myocardial oxygen consumption, resulting in angina attack. For angina pectoris attack at rest, patients should rest immediately, while sublingual nitroglycerin or isosorbide dinitrate and other drugs to alleviate symptoms. If conditions permit, should seek medical attention in time, relevant examination and treatment to prevent further deterioration of the disease.