Medical Treatment for Mitral Regurgitation
The only proven treatment for mitral regurgitation is surgery, although medication may temporarily decrease symptoms. There are two symptoms that predicate mitral valve surgery: falling ejection fraction and dilation (increased diameter) of the left ventricle.
Patients with mitral regurgitation in which the left ventricle has already decompensated or who cannot undergo surgery for other reasons (e.g., severe lung disease, advanced cancer) may be treated with several medications to decrease symptoms. These medications may include the following:
Diuretics. By decreasing the amount of salt and fluid in the body, diuretics decrease the amount of fluid that accumulates in the lungs and causes breathing problems. The diuretic most commonly prescribed for mitral regurgitation is furosemide (Lasix). Furosemide is usually taken one or two times a day at doses of as little as 20 mg daily to doses up to 200 mg twice a day or more. A newer diuretic, indapamide (Lozol), is usually prescribed at a dose of 2.5-5 mg daily. Sometimes, two diuretics are prescribed simultaneously. Together, they may have a synergistic effect on the kidney, increasing salt and fluid excretion.
Besides causing frequent urination, the main side effect of these medications is excretion of potassium in the urine, which may lower the level of potassium in the blood. Because of this, the doctor may periodically check potassium level; if it is low, he or she may prescribe a potassium supplement.
ACE inhibitors. In very simplified terms, ACE inhibitors help "open up" (dilate) the arteries of the body, making it easier for the heart to pump blood forward into the aorta and throughout the body, thus decreasing the amount of blood that regurgitates across the leaky mitral valve back into the left atrium.
There are many ACE inhibitors available, including benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec), fosinopril (Monopril), lisinopril (Prinivil , Zestril), quinapril (Accupril), ramipril (Altace), and trandolapril (Mavik). Most of the ACE inhibitors need only be taken once dailyseveral are taken two or three times daily.
The ACE inhibitors are usually tolerated well. In approximately 10 percent of patients, a chronic, nonproductive cough develops. Hypotension (too low blood pressure) may occur. Because the ACE inhibitors can affect kidney function and raise the potassium level, kidney function and potassium levels are monitored during the first several weeks of therapy and then periodically thereafter. Though it is rare, ACE inhibitors may produce a sudden swelling of the lips, face, and cheek areas; this is due to an allergic reaction that can occur at any time during therapy. If this occurs, the patient's physician should be contacted immediately.
Angiotensin Receptor Blockers. The angiotensin receptor blockers (ARBs) are a new class of medications that are similar in some respects to ACE inhibitors. Angiotensin receptor blockers act to help "open up" (dilate) the arteries of the body, making it easier for the heart to pump blood throughout the body.
Currently available ARBs include candesartan (Atacand), irbesartin (Avapro), losartin (Cozaar), telmisartin (Micardis), and valsartan (Diovan). The ARBs generally are taken once a day and do not commonly produce significant side effects. Rarely, ARBs may interfere with or worsen kidney function.
Digoxin. Digoxin (Lanoxin) acts to help the heart pump a little more vigorously, which leads to a modest increase in the ejection fraction (the percentage of blood pumped out of the left ventricle with each contraction). Occasionally, digoxin is prescribed for patients with mitral regurgitation and a left ventricle that no longer contracts normally in an effort to decrease symptoms. Digoxin is taken once a day, usually at a dose ranging from 0.125-0.375 mg daily. Unless the blood levels of digoxin get too high, no noticeable side effects are produced.
The turbulent blood flow across the leaky mitral valve makes the valve predisposed to developing an infection. Infection of a heart valve is called endocarditis. Therefore, patients with mitral regurgitation who are to undergo any type of procedure in which there is the potential for bacteria to enter the bloodstream and to then infect the mitral valve are treated with antibiotics at the time of the procedure to decrease the chances of valve infection. This practice of administering antibiotics to prevent valve infection is called endocarditis prophylaxis.
Procedures for which endocarditis prophylaxis is usually administered include but are not limited to:
- Certain dental procedures
- Certain invasive imaging procedures (e.g., bladder cystoscopy)
Patients with mitral regurgitation who undergo a dental or medical procedure should inform their doctors of their condition and should ask whether antibiotic endocarditis prophylaxis is necessary.