How is a biventricular pacemaker or defibrillator implanted?

At the time of either pacemaker or defibrillator implantation, an extra “third wire” also known as a left ventricular lead is placed. This is threaded to the heart the same way as other pacemaker or defibrillator leads, except it is then further threaded from the right atrium into another vein that leads to the surface of the left ventricle. It’s a little more tricky to get that third wire in place, but is achievable in about 95% of cases. Otherwise, the rest of the procedures the same as standard pacemaker or defibrillator implantation. Please see descriptions of those procedures.