A pacemaker wire, also called a lead, is a thin wire which connects to the generator of the device at one end and the heart at the other. Each pacemaker may have two or more wires to fit into the right atrium and the right ventricle and sometimes the left ventricle. Wires have an electrode at the end which connects to the heart in order to pick up its natural electrical impulses and send that information back to the generator.
There are three main types of pacemaker. One uses a pacemaker wire to connect the generator to the right ventricle. The second connects wires to both the right ventricle and atrium, and the third connects the generator to the left and right ventricles as well as the right atrium. The type used will depend on the patient’s condition and which type of pacemaker is ideal.
The pacemaker wire comes in several forms, although most are made from metal and feature some sort of coating for insulation. Some have a screw-in design while others have small tines at one end to connect to the body. Wires may be straight and narrow, or have a “J” or similar shape to fit into the atrium more effectively. Many pacemakers use a combination of leads to connect to various areas of the heart.
Wires which feature the screw-in mechanism are better able to stay in place soon after implantation. Those with tines, however, are often more accurate at pinpointing heart irregularities. Wires which feature a screw device are more common, but a doctor will be the final judge at which type of pacemaker wire is needed for each patient.
During placement, the pacemaker wire is inserted into the vein on the upper left-hand side of the chest, in the same area where the generator is placed. Doctors generally use a fluoroscope, which is a type of X-ray, to view the wires as they are strung through the veins and into their proper positioning at the heart. This is usually considered a minor surgery, and patients are not typically put under using general anesthesia. The operation is often performed in a clinic or the doctor’s office.
It is very rare for a pacemaker wire to malfunction, as they are relatively simple in design. More commonly, infection may occur in the pacemaker pocket, and the entire system is replaced. Very rarely a particular model of pacemaker or lead will be recalled due to faulty design or function. Occasional checks with the doctor are needed to ensure that the device is working correctly. Pacemakers are replaced once every five to ten years when the batteries weaken.