What is the real pharmacological rationale for beta-receptor blocking agents?

The intake of beta-receptor blocking agents may result in an improvement in the quality of life by reducing the frequency of angina pectoris attacks. The mode of action is a decrease of MVO2, mostly achieved by a reduction of the heart rate of about 20% during conditions of stress. The minimal oral dosages necessary to achieve this effect have not yet been well defined for the different beta-receptor blocking drugs available. Distinctly lower dosages may be sufficient. Considering these facts, the controversial points of view on the different properties of beta-receptor blocking agents should be re-examined.