Beta-blockers for systolic heart failure
When your heart begins to fail, your body tries to compensate for decreased blood flow by stimulating the heart to pump faster and more forcefully. Your nervous system does this by releasing a chemical called epinephrine into your blood and by releasing norepinephrine from nerve endings on the heart. At first, these chemicals (epinephrine and norepinephrine) increase the pumping action of your failing heart. Eventually, however, increased levels of epinephrine can actually make your heart failure worse, probably by causing damage to the heart muscle cells over time.
Beta-blockers work by blocking the action of epinephrine and norepinephrine to slow your heart rate and reduce the strength of each contraction. Beta-blockers may actually cause your symptoms to get worse at first. However, in the long term, beta-blockers can prevent worsening of heart failure and, in some cases, improve heart function. These medicines may also block the development of serious irregular heart rhythms and lower the risk of sudden death.
How well do beta-blockers work? Beta-blockers were initially tested in the late 1970s. However, it was not until 15 years later that a major study of one beta-blocker called carvedilol proved that this class of medicines could help people with heart failure. The carvedilol study found that for people with heart failure, the death rate was reduced by 65% in those who took carvedilol compared with those who took a placebo.1 Similar results have been found for several different beta-blockers, including metoprolol and bisoprolol.
Because the beneficial effects of beta-blockers are so clear, doctors are more consistently prescribing them for all types of heart failure. Beta-blockers are considered a first choice in drug treatment for heart failure, along with diuretics and angiotensin-converting enzyme (ACE) inhibitors.
| Author: | Robin Parks, MS | Last Updated: September 1, 2006 |
| Medical Review: | Caroline S. Rhoads, MD - Internal Medicine Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology | |
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