A pacemaker is a tiny, lightweight, electrical device. This keeps track of your heartbeat and when necessary it gives a small low-voltage electrical pulse to your heart, which forces it to beat.
The pacemaker device consists of two parts:
First, the battery unit, or pulse generator. This regulates how often signals are sent to the heart.
The second part is the lead, which consists of one or two wires that carry electrical messages back and forth between the heart and the pacemaker.
The device is much smaller than a deck of cards and weighs slightly more than an ounce.
To begin your procedure, your doctor first chooses an area to place the lead or wire, usually under the collarbone on the left or right side of your chest, or in your stomach area. This part of your body will be shaved and scrubbed with a special disinfectant soap. You will be given one or more shots of numbing medicine in the area with a small needle. This may feel slightly uncomfortable, like a small pinch and you may also feel a slight tingling or burning sensation.
In order to attach the wire leads to your heart, your doctor needs a pathway through one of your veins. Once the area is numb, a needle is used to guide an introducer into your vein. The introducer is a plastic instrument that creates this pathway, and keeps it open during the procedure. Your doctor then puts one lead wire through the introducer and will most commonly guide it into your heart's ventricle using a special x-ray screen. If a second lead is used, this will also be inserted through the same pathway, and into your heart's atrium.
Once the leads are in place, the introducer will be removed and the pulse generator will be attached. Your doctor will then test the device and program it to respond to your specific heart problem. Although lead testing is not painful, it is probably the loudest part of the procedure. You may hear information being called out. Moving the lead around and re-testing several times is not unusual.
The next step is to put the generator in a "pocket," usually in your upper left chest area. To do this, a small incision is made in your skin or sometimes in your muscles and the generator is tucked inside. This pocket is then closed with stitches and a bandage is placed over the incision site.