Artificial Heart Valves


Artificial heart valve

You've undoubtedly heard it said -- the human body is an amazing machine. But as amazing as it is, there are times when disease, injury or extensive wear and tear leaves it working at a less-than-efficient and even dangerous level. Such is the case with the heart and its valves.

There are four valves of the heart which ensure that blood flows in the right direction at the proper rate and that blood flow is stopped when necessary. The valves are the aortic, mitral, pulmonary and tricuspid valves [source: Mayo Clinic]. If any of the valves in your heart become rigid, fail to completely seal or get stretched out over time, your quality of life will suffer to one degree or another. It could be something as seemingly minor as periodic fainting or it could lead to a life-threatening heart attack. In any case, you may one day find yourself in need of valve replacement surgery [sources: MedlinePlus; HealthGrades]. Artificial valves come in two primary forms -- biological and mechanical. Each option carries its own risks and advantages. Your doctor will take your age and lifestyle into account before determining which choice is best for you [source: Aranki].

Heart valve replacement surgery was first introduced 50 years ago as an option for patients suffering from heart disease [source: Aranki]. As of 2011, in the United States alone, approximately 70,000 to 80,000 valve replacement surgeries are performed each year [source: Harvard]. Heart surgery always carries risks that can range from bleeding to an irregular heartbeat to stroke and heart attack [source: Mayo Clinic]. Today, however, artificial valve replacement surgery has a high rate of success [source: MedlinePlus].

But not all valves are the same. Next, we'll look at different types of mechanical heart valves.

Types of Mechanical Heart Valves

Artificial heart valves can be biological or mechanical. Biological valves are made of human or animal tissue (cow and pig hearts are often used) and usually have a shorter life span than mechanical valves. Mechanical valves, however, require the patient to take anti-coagulant medication continually to prevent blood clots [source: HealthGrades]. If you're a younger patient it's likely your doctor will recommend a mechanical valve because of its durability. The exception to this rule is younger patients who are seeking to get pregnant or are highly active and prone to injuries that could result in bleeding. In either case, the blood-thinning medications used after replacing a valve with a mechanical device could pose problems which would make a biological valve a better choice [source: Harvard].

Mechanical valve options have evolved with time. The first commercially available option was a ball-and-cage design [source: Aranki]. As blood flows, the ball is pushed forward to open the valve, yet the cage restrains the ball from moving too far. Likewise, as blood flow decreases the ball rolls back into place to close the valve and prevent regurgitation. The ball-and-cage structure can be made of ceramic, steel or titanium [source: MedlinePlus].

In recent years, a mechanical valve which uses leaflets has become increasingly popular [source: Aranki]. The leaflets are like flaps that open and close with the beating of the heart. Think of them as windows that open in one direction but not the other. Leaflet valves may come with two or three leaflets per valve, and are named bileaflet or trileaflet valves accordingly.

Mechanical valves are extremely durable, but biological valves need to be replaced after 10 to 15 years [source: Harvard].

As you might guess, swapping out heart valves isn't easy. Next, let's examine several heart valve replacement procedures.

Heart Valve Replacement Procedure

Your doctor will put you through a comprehensive examination prior to surgery which could involve x-rays and a variety of heart imaging tests and catheterization. Your blood will also be tested to ensure your kidneys are working as they should and to make certain you don't have any blood diseases [source: Harvard].

During surgery, your doctor will make a large cut in your chest and saw the breastbone apart to reach your heart. You will be hooked to a heart and lung machine which will keep the proper amount of oxygen in your blood and continue to pump blood throughout your body. Once the heart and lung machine is working, your surgical team will cool your heart and stop it briefly so the muscle can be cut and the diseased valve removed. The new valve will then be stitched into position. Next, your heart will be warmed, allowing it to begin beating again. If it doesn't immediately begin beating, it may need to be electrically shocked. Once your heart is again pumping and it's clear that everything is working properly, the heart and lung machine will be removed and the primary part of the surgery will be complete. That may sound a little frightening, but understand that other, less invasive types of heart replacement valve surgery are currently being tested [source: Harvard].

After surgery, you'll remain in the intensive care unit for two or three days. Your doctor may choose to do further imaging tests on your heart at the hospital or wait until after you have gone home and recovered. This will help ensure that your new valve is operating as designed [source: Harvard]. It'll also be necessary to take blood-thinning medication for the foreseeable future. Your doctor will work to determine the proper amount of blood-thinner for your body.

Heart valve replacement isn't something you encounter every day, but with a little research and preparation, it doesn't have to be so scary. Read ahead for links, resources and lots more information on the next page.

Related Articles

Sources

  • Aranki, Sary, MD. MedscapeEducation. "Heart Valve Surgery." June 30, 2006 (Oct. 7, 2011) http://www.medscape.org/viewarticle/537652
  • Bauder, David. "Barbara Walters' New Heart Surgery Special." Huffington Post. Feb. 2, 2011 (Oct. 9, 2011) http://www.huffingtonpost.com/2011/02/02/barbara-walters-heart-special-drugs_n_817330.html
  • Doheny, Kathleen. "Barbara Walters' Heart Surgery: Heart Specialists Say Procedure is Common, Outlook Good." WebMD. (Oct. 9, 2011) http://www.webmd.com/heart-disease/news/20100511/barbara-walters-heart-surgery
  • Harvard Health Publications. "Heart Valve Replacement." (Sept. 30, 2011) http://www.bing.com/health/article/harvard-1000244402/Heart-Valve-Replacement?q=heart+valve+replacement
  • HealthGrades. "Heart ValveReplacement." (Sept. 30, 2011)
  • Mayo Clinic. "Heart Valve Surgery." (Sept. 30, 2011) http://www.mayoclinic.org/heart-valve-surgery/
  • MedlinePlus. "Heart Valve Surgery." (Sept. 30, 2011) http://www.nlm.nih.gov/medlineplus/ency/article/002954.htm