What is the rationale for using beta-blockers in managing angina pectoris?

The rationale for using beta-blockers in managing angina pectoris is primarily centered on their ability to decrease myocardial oxygen demand. Beta-blockers work by blocking the effects of adrenaline on beta-adrenergic receptors, which results in a reduction in heart rate and myocardial contractility. By decreasing heart rate, the heart is able to utilize less oxygen, thereby alleviating the stress on the heart during episodes of angina.

Additionally, by lowering the workload on the heart, these medications help prevent episodes of angina that are triggered by activities that demand greater oxygen supply. This is particularly important in patients with coronary artery disease, where angina is often a symptom of inadequate oxygen supply to the myocardium due to narrowed coronary arteries. Thus, the comprehensive effect of beta-blockers in reducing heart rate and contractility directly correlates with their role in managing angina by diminishing myocardial oxygen demand.