Leads, Pacemaker, Implantable, Endocardial
Definition : Leads designed to conduct electrical pacing signals from the pulse-generating unit of an implantable pacemaker to the heart (i.e., endocardial or transvenous leads) and then conduct the myocardial signals back to the unit. These leads typically consist of flexible wires that are completely isolated except at the electrode tip that makes contact with the heart. The leads are positioned in the right atrium or right ventricle through the vascular system (e.g., subclavian vein, superior vena cava). They may be fixed using barbs or screw-type terminals (i.e., active fixation) or through flanges or tinned tips (passive fixation). The other ends of the leads are attached through a connector to the pulse generator that is usually implanted in a surgical pocket in the upper chest near the collarbone. Implantable pacemaker endocardial lead configurations may be unipolar, with one active electrode contact on the heart; or bipolar, with two active contacts; lead size, connector type, and other characteristics of the leads must be compatible with the pulse generator used.
Entry Terms : "Pacemaker Leads, Endocardial" , "Electrodes, Endocardial" , "Leads, Pacemaker, Transvenous" , "Electrodes, Implantable Pacemaker"
UMDC code : 12900