What is a ventricular assist device (VAD)? When should patients with heart failure be considered for a VAD?

A ventricular assist device (VAD) is a mechanical pump device that is surgically implanted to help maintain the pumping ability of a heart that has become so severely weakened that it is unable to effectively function on its own. In patients who have very severe heart failure and are eligible, these mechanical heart pumps can significantly improve their symptoms and their survival rate.

Most VADs that are implanted support the left side of the heart (left ventricle), because this is the main pumping chamber of the heart. These pumps are referred to as left ventricular assist devices (LVAD). There are also other pumps, used less frequently, that help both the left and right ventricles pump blood, known as biventricular assist devices (Bi-VAD).

The typical LVAD involves a tube that is surgically connected to the left ventricle and directs the blood from the ventricle into the pump (Figure 15). The pump then sends blood out into the aorta (the large blood vessel leaving the left ventricle, delivering blood to the entire body). This effectively bypasses the weakened ventricle but delivers a full amount of blood and oxygen to the body and all the vital organs.

The VAD is connected to a “system controller,” which is connected to the tube that exits from the abdomen (the “driveline”). This is powered by an external battery pack.

A VAD must always be connected to its power source, either the portable battery pack or to the power base console, which is plugged into an electric wall socket.

The battery pack can be worn in a small holster, making it easy to move around without being “plugged” into the wall. Technologic advances in the portable battery pack have improved the quality of life and independence of patients who are now free to move around for several hours at a time with the portable pack. Many patients who are home with a VAD are capable of living an active lifestyle and to resume some of their normal routines and activities.

A heart failure patient can be considered for a VAD after all medical and device therapy has failed and the patient has developed severe end-stage heart failure. Often, these patients are unable to leave the hospital, and their heart may have become so weakened that they are now dependent on permanent intravenous (IV) medications to help the heart pump stronger.

In these patients a VAD may help the heart pump blood more effectively until a heart becomes available for transplantation (referred to as a “bridge to transplantation”). For others who do not qualify for heart transplantation but who are still suffering from severe heart failure, an LVAD may be implanted as a permanent pump to assist their heart, so-called destination therapy.