What mechanism of action is associated with calcium channel blockers in angina treatment?

Calcium channel blockers are commonly used in the treatment of angina due to their ability to decrease myocardial oxygen demand. They achieve this primarily by relaxing the smooth muscles in the vascular system, leading to vasodilation of coronary arteries and peripheral blood vessels. This dilation decreases the resistance against which the heart has to pump, thereby reducing systemic vascular resistance and ultimately lowering the workload of the heart.

By decreasing myocardial oxygen demand, calcium channel blockers can alleviate the symptoms of angina, which is often triggered by an imbalance between oxygen supply and demand in the heart muscle. This response can help to reduce frequency and severity of anginal episodes in patients who experience them due to conditions such as coronary artery disease.

Other choices do not align with the primary actions of calcium channel blockers. For instance, increased heart rate would elevate myocardial oxygen demand rather than decrease it. Enhanced contractility would also lead to increased myocardial workload, worsening angina. Increased vascular resistance contradicts the vasodilative effects that calcium channel blockers are known for, as these agents work to reduce resistance and facilitate better blood flow to the heart muscle.