Beta-blockers, such as metoprolol (Lopressor, Toprol-XL), were used to treat high blood pressure for years before their benefit to patients with heart failure was discovered. The drugs make the heart beat more slowly and less forcefully by preventing adrenaline from causing the coronary arteries to constrict. Studies showed beta-blockers reduce the number of deaths from heart failure by 50 percent. The drugs also slow the progression of the disease, improve the measure of heart failure severity, and reduce hospitalizations. Beta-blockers reduce the size of the heart and increase the hearts pumping ability, helping return the organ to normal functioning.