A ventricular assist device (VAD) is an implantable mechanical pump that helps pump blood from the lower chambers of your heart (the ventricles) to the rest of your body. VADs are used in people who have weakened hearts or heart failure. Although VADs can be placed in the left, right or both ventricles of your heart, they are most frequently used in the left ventricle. When placed in the left ventricle they are called left ventricular assist devices (LVADs).You may have a VAD implanted while you wait for a heart transplant or for your heart to become strong enough to effectively pump blood on its own. Your doctor may also recommend having a VAD implanted as a long-term treatment if you have heart failure and you're not a good candidate for a heart transplant.The procedure to implant a VAD requires open-heart surgery and has serious risks. However, a VAD can be lifesaving if you have severe heart failure.