Heart failure is a condition in which the heart can't pump blood effectively to the lungs or the rest of the body.
This can be because the person has developed a weakened heart muscle or because the heart muscle has thickened, making it difficult to fill the heart and backing up blood into the lungs.
With heart failure, the weakened heart pumps less blood than usual, causing the kidneys and adrenal glands to produce chemicals that help the body to hold onto salt and water.
In addition, the blood...
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
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
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.