Medic 14 is dispatched to a call to a residence for difficulty breathing. On arrival crew members find a 52-year-old male sitting in bed and working a hand pump. He says his left ventricular assist device (VAD) alarm went off, and his device does not appear to be working. He says he has a diseased heart and is on the list for a transplant. He also says the only thing keeping him alive at this point is his hand pump, which circulates his blood. He denies any chest pain or difficulty breathing at this time, but needs a new battery for his device. The patient is transported to the hospital where he received his device for evaluation and placement of a new battery.
Just recently, VADs were in the news when former Vice President Dick Cheney was released from a suburban Washington hospital following surgery to install what media described as a "pump that helps his failing heart work." Cheney, 70, has had five heart attacks since he was 37 and suffers from congestive heart failure. He disclosed in a statement last July that he had undergone surgery the previous week after what he called "entering a new phase of the disease when I began to experience increasing congestive heart failure." Cheney said the pump, a left ventricular assist device, would allow him to resume an active life.
The left ventricle is the large, muscular chamber of the heart that pumps blood out to the body. A ventricular assist device (VAD) is a battery-operated mechanical pump-type device that's surgically implanted. It helps maintain the pumping ability of a heart that can't effectively work on its own. This device is sometimes called a "bridge to transplant."
People awaiting heart transplants often must wait a long time before suitable hearts become available. During this wait, patients' already-weakened hearts may deteriorate and become unable to pump enough blood to sustain life. A VAD can help a weak heart and buy time for a patient.
A common type of VAD has a tube that pulls blood from the left ventricle into a pump. The pump then sends blood into the aorta (the large blood vessel leaving the left ventricle). This effectively helps the weakened ventricle. The pump is placed in the upper part of the abdomen. Another tube attached to the pump is brought out of the abdominal wall to the outside of the body and attached to the pump's battery and control system. VADs are now portable and are often used for weeks to months to years. Patients with VADs can be discharged from hospitals and have an acceptable quality of life while waiting for donor hearts to become available.
VADS are used in three clinical situations:
- As a "bridge to transplant" in people with severe chronic heart failure. That is, they can help ease the work of the heart in people waiting for transplantation.
- In some patients with heart failure, insertion of a VAD can allow a damaged left ventricle to "rest" and repair itself. Examples in which the underlying cardiac problem can often improve include heart failure after cardiac surgical procedures, major acute heart attacks and acute myocarditis.
- VADs can be used as "destination therapy" in people with severe end-stage heart failure who are not candidates for transplantation (because of other factors such as age, kidney disease or lung disease), and who have an extremely poor prognosis without mechanical support. In these patients, the VAD is the treatment; there is little reasonable expectation that it can ever be removed.
In a study published in Circulation in 2005, VADs restored failing hearts in some patients with heart failure, eliminating the need for transplant. According to an abstract presented at the American Heart Association's 2005 Scientific Sessions, VADs reduced the risk of death in end-stage heart failure patients by 50% at six and 12 months and extended the average lifespan from 3.1 months to more than 10. These devices are becoming more ubiquitous, and EMS systems will be encountering them on a more frequent basis.