A biventricular pacemaker is a type of implantable pacemaker designed to treat heart failure. This type of therapy becomes necessary when the two lower chambers of the heart, the ventricles, do not pump in unison. A biventricular pacemaker helps the ventricles to contract more efficiently. This type of pacing is called cardiac resynchronization therapy (CRT).

Biventricular pacemakers are relatively new. Previous pacemakers were used to pace only the right side of the heart. They were usually inserted when the heart beat too slowly (bradycardia). By contrast, biventricular pacemakers pace both the right and left sides of the heart simultaneously. The device is also designed to pace the major pumping chamber (the left ventricle) from 2 different sites simultaneously. This helps the left ventricle pump blood more efficiently by synchronizing the contraction of different segments of the failing left ventricle. These pacemakers do not increase heart rate unless needed when the heart rate slows below a certain level.

Biventricular pacemakers are manufactured either as “stand alone” devices, or with built-in implantable cardioverter defibrillator (ICD). Approved by the U.S. Food and Drug Administration in May 2002, studies have shown that an ICD with biventricular may reduce mortality by up to 40 percent in patients with heart failure, as well as improve quality of life.

Like standard pacemakers and defibrillators, a biventricular pacemaker may be implanted in the patient’s chest during a minor surgery or in conjunction with open heart surgery. Once implanted, patients will have regular checkups with a physician to make sure the biventricular pacemaker is working properly.