How Nitrates Treat Systolic Heart Failure
Topic Overview
Nitrates are
medicines that act as vasodilators because they mimic the effect of one of the
body's own natural chemicals called nitric oxide, which causes arteries and
veins to widen (dilate).
Nitrates can improve
heart failure symptoms by:
- Dilating the coronary arteries. These are the arteries that carry blood to the heart itself.
If your heart failure is caused by coronary artery disease, increasing the
width of these arteries may help deliver more blood to your heart and may help
it pump more efficiently.
- Dilating the veins. The large veins of the body, particularly in the legs, have the
ability to hold a lot of blood. By dilating these veins, nitrates reduce the
amount of blood returning to the heart, thereby reducing the buildup of fluid
in your lungs.
- Dilating the systemic arteries. Systemic arteries are blood vessels that carry blood to the
rest of the body (excluding the heart and lungs). The blood pressure in these
arteries determines how hard your heart needs to pump. By dilating these
arteries, nitrates may relieve some of the work your heart needs to
do.
- Dilating the pulmonary arteries. Dilating the arteries of the lungs (pulmonary arteries) also reduces the
amount of work your heart needs to do. This effect is particularly helpful for
the right side of your heart, which is often weakened along with the left side
of the heart in some forms of heart failure.
How well do nitrates work?
For heart failure, hydralazine is
typically used along with a nitrate. But nitrates may be used alone, without
hydralazine, if you are taking it to relieve
angina symptoms.
If you take hydralazine
with a nitrate, you will also take other medicines for heart failure such as
ACE inhibitors and beta-blockers. This combination of medicines may help
relieve symptoms and lower the risk of early death. This benefit has been shown
in African Americans but has not been shown in other groups of people.1
Vasodilators are often combined with
other medicines to treat
heart failure. Hydralazine taken with a nitrate may be
used as an alternative to angiotensin-converting enzyme (ACE) inhibitors if ACE
inhibitors cannot be tolerated.
References
Citations
- Hunt SA, et al. (2009). 2009 focused update
incorporated into the ACC/AHA 2005 guidelines for the diagnosis and management
of heart failure in adults. A report of the American College of Cardiology
Foundation/American Heart Association Task Force on Practice Guidelines.
Circulation, 119(14): e391–e479.
Credits
| By | Healthwise Staff |
|---|
| Primary Medical Reviewer | E. Gregory Thompson, MD - Internal Medicine |
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| Specialist Medical Reviewer | Theresa O'Young, PharmD - Clinical Pharmacy |
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| Last Revised | August 9, 2010 |
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Last Revised:
August 9, 2010
Hunt SA, et al. (2009). 2009 focused update
incorporated into the ACC/AHA 2005 guidelines for the diagnosis and management
of heart failure in adults. A report of the American College of Cardiology
Foundation/American Heart Association Task Force on Practice Guidelines.
Circulation, 119(14): e391–e479.
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