What is the main action of anti-anginal medications?

The primary action of anti-anginal medications is to decrease the oxygen demand on the heart. These medications are designed to alleviate the symptoms of angina, which is primarily caused by an imbalance between the oxygen supply and demand in the heart muscle, often due to coronary artery disease.

By reducing the workload of the heart and the amount of oxygen it requires, anti-anginal drugs help prevent angina attacks. This is achieved through various mechanisms depending on the specific class of medication. For instance, nitrates can relax and dilate blood vessels, thereby decreasing the overall workload and oxygen requirements of the heart. Beta-blockers reduce heart rate and contractility, further lowering oxygen demand. Similarly, calcium channel blockers decrease heart contractility and promote vasodilation, which also helps lessen the heart's need for oxygen.

Overall, the goal of anti-anginal therapy is to manage symptoms and improve the quality of life for patients with angina by ensuring that the heart receives adequate oxygen without exceeding its demand.