Beta Blockers are drugs that slow the heart rate, decrease cardiac output, lessen the force with which the heart muscle contracts and reduce blood vessel contraction. This lessens the work load for your heart, which means there is less energy demand. If your heart has blocked coronary arteries, the regional blood (and thus the energy) supply is limited. Beta blockers lower the work load and thus help match a lower supply of energy to a lower capacity of the heart to do its job (pump blood around your body).
Angina happens when the heart is working harder than the blood (energy) supply allows for. Beta blockers often lessen the severity and frequency of angina attacks, but don’t do anything to correct the problem of blockages and insufficient blood supply.
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Your risks of heart disease:
Hope this helps,