Congestive Heart Failure 101
By Carl Bianco
Treatment of CHF
- Diuretics (water pills) are medications used to increase the amount of sodium (Na+) and water excreted by the kidneys. This reduces the blood volume and the amount of blood that the heart has to pump, thereby reducing its workload. The goal is to maintain ideal weight by eliminating edema. Diuretics include:
- metalazone (Zaroxolyn)
- furosemide (Lasix)
- bumetanide (Bumex)
- Vasodilators are groups of medications that dilate or enlarge blood vessels. During CHF, the blood vessels are often constricted due to the activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system. When vasodilators are used, they decrease the resistance and blood pressure against which the heart must beat, thus increasing the cardiac output. Angiotensin converting enzyme inhibitors (ACE inhibitors) are very effective vasodilators. This is one of the few medications that have actually been shown to prolong life in CHF patients. ACE inhibitors reduce blood pressure and fluid retention by preventing the renin-angiotensin-aldosterone system from working. ACE inhibitors include:
- captopril (Capoten)
- enalapril (Vasotec)
- lisinopril (Zestril, Prinivil)
- benazepril (Lotensin)
- fosinopril (Monopril)
- quinapril (Accupril)
- Angiotensin receptor blockers block the effects of angiotensin instead of blocking its production. Angiotensin receptor blockers include:
- losartan (Cozaar)
- irbesartan (Avapro)
- valsartan (Diovan)
These medications do not cause the side effect of cough produced by ACE inhibitors.
- Nitroglycerin dilates veins and can be taken under the tongue (Nitrostat), intravenously, by mouth (Isosordil, Sorbitrate, ISMO), or by skin patches (Nitro-Dur, Transderm-Nitro).
- Calcium channel blockers dilate blood vessels and are sometimes used to treat CHF, especially when ischemia is present. These drugs also tend to decrease the force of the heart's contraction, however, and so can worsen CHF. Calcium channel blockers include:
- nifedipine (Procardia XL, Adalat CC)
- diltiazem (Cardizem)
- verapamil (Calan, Isoptin)
- amlodipine (Norvasc)
- felodipine (Plendil)
- nisoldipine (Sular)
- Hydralazine is a vasodilator that acts on arteries. It is used less frequently since ACE inhibitors have been found to be more effective.
- Alpha blockers block the alpha-adrenergic receptors of the sympathetic nervous system, thereby dilating blood vessels. Alpha blockers include prazocin (Minipress) and doxazosin (Cardura). Side effects include rapid heartbeat and low blood pressure.
- Digitalis medications (digoxin, Lanoxin) increase the force of contraction of the heart muscle and also control abnormal heart rhythms, especially atrial fibrillation and atrial flutter. Therefore, digitalis is most useful when someone with atrial fibrillation or atrial flutter has CHF (a fairly common scenario). It improves heart function without increasing mortality. It has many side effects, including nausea, vomiting, many types of abnormal heart rhythms, confusion and negative interactions with other medications.
- Beta blockers have been found to be useful for CHF. By blocking the beta-adrenergic receptors of the sympathetic nervous system, the heart rate and force of contraction are decreased. Of course, this must be done carefully because decreasing these two things can actually worsen CHF. Beta blockers include:
- metoprolol (Lopressor, Toprol-XL)
- atenolol (Tenormin)
- carvedilol (Coreg)
- Sympathomimetic medications act similarly to the sympathetic nervous system and are used when CHF is severe, such as in cardiogenic shock. They treat CHF by increasing the force of the heart's contraction. Sympathomimetic drugs include dopamine (Inotropin) and dobutamine (Dobutrex). Because they must be taken intravenously and are extremely strong, these medications are used mainly when CHF has become life threatening. They can cause abnormal heart rhythms and ischemia.
Occasionally, there are circumstances when surgery can treat CHF. The most common surgical procedures are:
- Heart valve replacement When a heart valve malfunctions, valve replacement can reverse the symptoms. In some cases, this can be a life-saving procedure.
- Congenital heart defect correction Surgical repair of congenital heart defects is frequently used to restore normal functioning as much as possible.
- Coronary artery bypass If Coronary artery disease (CAD) is the cause of CHF, then correcting the CAD with coronary artery bypass grafts can be useful.
- Heart transplant When CHF persists and worsens despite maximum therapy, then a heart transplant can be an option. Patients considered for transplants usually suffer from severe symptoms (Class 4 on the New York Heart Association's scale), have ejection fractions of 15 to 20 percent and have one year survival rates of 50 percent. The improvement in anti-rejection drugs (especially cyclosporine) have increased survival from this procedure. There are also some devices that assist the severely failed heart, such as an intra-aortic balloon pump and a left ventricular assist device. These are used as bridges to keep a person alive until a donor heart can be found.