How do beta-blockers help in reducing angina symptoms?

Beta-blockers are effective in reducing angina symptoms primarily by decreasing cardiac workload. They achieve this by slowing the heart rate and lowering blood pressure. When the heart beats more slowly, it requires less oxygen, which is particularly important in patients with angina, where oxygen supply to the heart muscle is insufficient due to narrowed coronary arteries.

Additionally, by lowering blood pressure, beta-blockers decrease the force with which the heart has to pump, further reducing overall cardiac workload. This dual action of reducing heart rate and blood pressure helps to alleviate the symptoms of angina by allowing the heart to operate more efficiently, thereby minimizing the incidence of angina attacks.

In contrast, increasing heart rate would exacerbate angina symptoms instead of alleviating them. While dilation of blood vessels is a mechanism associated with other classes of antianginal agents, such as nitrates, it is not the primary action of beta-blockers. Reducing blood volume is also not the main effect of beta-blockers; this is more pertinent to diuretics. Thus, the most accurate description of how beta-blockers assist in managing angina is by decreasing workload through their effects on heart rate and blood pressure.