Tuesday, October 19, 2010

HUMAN HEART WHICH IS ARTIFICIAL


Hi I read about a interesting article that Human being lives without heart. Don't get shocked he can live with a man made Artificial Heart. Read this you can learn more.

What is an artificial heart?
An artificial heart is an extra ventricle (pumping chamber) capable of pumping blood around the body of a person whose own heart is failing. The pump itself is made of a combination of metal and plastic and consists of a small pumping chamber lined by a special material that prevents blood clots from forming. The pumping chamber may be implanted within the body itself or may lie outside the body depending on the type of artificial heart being used. An artificial heart may be connected to a person in various ways to support the
left heart, the right heart or both sides of the heart ; it may be

• attached to the left atrium/ventricle and the aorta (called a “left ventricular assist device” or LVAD), or

• attached to the right atrium and pulmonary artery (called a “right ventricular assist device” or RVAD), or

• attached in both ways described above (called a “biventricular assist device” or BiVAD).

The device may bypass the weakened ventricle(s) either partially or totally.

Another type is the” total artificial heart” (TAH) which is a mechanical substitute for the entire heart. It is implanted after the person’s heart has been removed. This type is rarely used at present.


How does an artificial heart work?
Blood enters the artificial heart from the left or right atrium and is then pumped into the aorta or pulmonary artery, depending on which side of the heart is being supported.

The device is powered by either compressed air or electricity. A thin cable connects the pumping chamber to a control console from which the pump function is regulated. The control console may be a large box on wheels that stays beside the person and can move with the person when he or she walks around in the hospital. More recently, a much smaller controller with attachable batteries has been designed which can be worn by the person on a belt or vest. This allows the
person much greater freedom and mobility compared with the large console.

Who needs an artificial heart?
A person may require an artificial heart when his or her own heart fails and is unable to pump blood to meet the body’s needs. These people may have symptoms such as persistent tiredness, lethargy, shortness of breath on exertion or at rest, poor appetite, and swelling of their ankles. Function of other body organs such as the lungs, liver and kidneys may also be impaired as a
result of heart failure.

Reasons why the heart fails include:
• disease of the heart muscle itself (cardiomyopathy)
• disease of the arteries of the heart (coronary heart disease) and its
complications (e.g. a heart attack)
• severe viral infections of the heart (myocarditis)
• other less common diseases.

People with a failing heart are first treated with drugs that take the load off the heart and help it function better. Sometimes the heart failure is so severe that the drugs are ineffective. The other treatment option for these severely ill people is heart transplantation. Heart transplants are performed using hearts donated from people who suffer brain death; for example, as a result of a motor vehicle accident or a brain haemorrhage. These people’s hearts are working well despite brain death. Unfortunately there are not enough heart donors in this country to help all those people who need a heart transplant. Therefore, some of these people will die from their heart failure before a transplant can be performed. Artificial hearts may be used in these very ill people as a temporary measure until a donor heart becomes available, or to allow a person’s damaged heart to rest or recover following damage. Occasionally, artificial hearts are implanted as a last resort in people who are unsuitable for heart transplantation. Between twenty and thirty people receive artificial hearts in Australia each year. Most of these artificial hearts have been implanted as a bridge to heart transplantation. However, recently a small number have been implanted on a permanent basis as an alternative to heart transplantation.

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