Drug therapies provide the foundation of heart failure treatment at any stage. A physician or cardiologist may prescribe one or more of the following common types of medications to treat the disease and help manage symptoms. As noted, certain types of medication may be prescribed specifically for systolic or diastolic heart failure:
ACE (angiotensin converting enzyme) inhibitors
As the name implies, ACE inhibitors “inhibit” the production of angiotensin II, a chemical in the blood that causes blood vessels to contract. With less angiotensin around, the blood vessel walls relax, causing blood pressure to fall. The lower pressure means that the heart muscle does not have to work as hard to move blood through the body.
The action of ACE inhibitors also appears to inhibit the structural change in the heart associated with heart failure, called remodeling, which undermines the heart’s ability to pump blood.
Through numerous clinical trials, ACE inhibitors have proven generally effective in treating heart failure. Following an initial diagnosis of either systolic or diastolic heart failure, ACE inhibitors are the most-prescribed class of medication and a cornerstone of nearly every treatment regimen.
Currently under research is a class of complementary drugs called angiotensin II receptor blockers, which prevent angiotensin II from reaching receptors in the blood vessels.
Vasodilators cause the blood vessels to open, or dilate, which lowers the blood pressure. By reducing the resistance against which the heart muscle must pump blood, vasodilators enable the weakened heart to produce more blood flow.
ACE inhibitors work this way and can be considered a kind of vasodilator, but other drugs fall into the same category, as well. Nitroglycerin tablets, for example, are prescribed for patients who are unresponsive to ACE inhibitors or who cannot take them.
Diuretics stimulate the kidneys to draw more water and sodium from the bloodstream and remove it from the body as urine. Doing so relieves the backup of fluids in the tissues and lungs caused by heart failure. With less fluid to circulate, the blood on both the inflow and outflow sides of the heart drops in pressure.
Diuretics are prescribed to both systolic and diastolic heart failure patients.
Whereas the drugs described so far target structures outside the heart, such as the blood vessels, inotropes comprise a class of drugs that increase the strength of the contractions of the heart muscle itself.
When circulated in the bloodstream, an inotrope such as digoxin can help regulate the pulse of the heart and increase its output of blood, or ejection fraction, over time. Extracted from the leaves of Digitalis lanata, the foxglove plant, digoxin was once the gold standard in heart failure therapy. It and similar chemicals are sometimes referred to collectively as digitalis.
Beta blockers slow the heart rate by blocking the receptors on heart cells that receive the chemical signal to beat faster. In heart failure patients, the heart beats faster in an effort to make up for its lack of strength. Working faster means working harder, and for the ailing heart, the increased strain can be self-destructive. Beta blockers help patients manage their heart rates and minimize stress on the heart.
Anticoagulants, or blood thinners, reduce the blood’s tendency to form clots. Heart failure patients are more likely to develop clots because their hearts do not move the blood through the bloodstream as vigorously as healthy hearts do. In some patients, an anticoagulant may be prescribed because the patient suffers atrial fibrillation, or uncoordinated contractions of the atria that can allow blood to collect and clot within the heart.
Potassium aids the heart in the transmission of electrical impulses. Excessively low or excessively high potassium levels can lead to irregular heartbeats and dysfunction, so it is important for heart failure patients and their doctors to strike an appropriate balance. Diuretics cause the kidneys to remove potassium from the blood; patients taking diuretics may need to eat potassium-rich foods or take a potassium supplement. ACE inhibitors, on the other hand, cause the body to retain potassium, sometimes rendering a supplement unnecessary.