A biventricular pacemaker (also called CRT) is an electronic, battery-powered device that is surgically implanted under the skin.
When a pacemaker is implanted in the body, a one to two-inch incision is made beneath the collarbone and a small "pocket" is created for the pulse generator under the skin.
The device has 2 or 3 leads (wires) that are positioned in the heart to help the heart beat in a more balanced way. The leads are implanted through a vein in the right atrium and right ventricle and into the coronary sinus vein to pace the left ventricle. The primary purpose of a pacemaker is to maintain an adequate heart rate, either because the heart's natural pacemaker is not fast enough, or there is a block in the heart's electrical conduction system. Modern pacemakers are externally programmable and allow the cardiologist to select the optimum pacing modes for individual patients. Some patients with heart failure may benefit from a combination of CRT and an implantable cardiac defibrillator (ICD). These devices combine biventricular pacing with anti-tachycardia pacing and internal defibrillators to deliver treatment as needed.