Beta-blocking drugs were discussed in the chapter Angina, and the present discussion explains the rationale for their use in patients after a heart attack. Beta-blockers block the action of adrenaline and noradrenaline at receptor sites on the surface of cells. They cause a reduction in heart rate; therefore, less oxygen is required by the weakened heart muscle. They decrease the force of contraction of the heart muscles, and this further decreases the work and the amount of oxygen required by the heart. Most of the effects on the heart and arteries are related to this blocking of the actions of stress hormones. Beta-blockers stabilize the heart rhythm and can prevent premature beats such as those that are precipitated by mental and physical stress. They can prevent some episodes of ventricular fibrillation, which is the cause of sudden death.
Beta-blockers, statins to lower cholesterol, and aspirin are the only oral drugs that are proven by studies to prevent death from heart attacks. When beta-blockers are given to patients from day one after a heart attack and for up to two years, they significantly reduce the incidence of death from heart attack including sudden death. They also reduce the recurrent rate of subsequent heart attacks. About 70 of every 100 heart patients are eligible for treatment with beta-blockers, and these include patients who have angina after the heart attack. In the UK, a survey of actively practicing British consulting cardiologists was carried out to determine their practices when prescribing beta-blockers after a heart attack. Half of the cardiologists reported that they use beta-blockers in all patients who can take the drug starting about one week after the heart attack and continuing for about two years. The other half reported that they gave the beta-blockers to patients at high risk. It is strongly recommended to give a beta-blocker to all post heart attack patients from day seven if there is no contra¬indication to their use.

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