MEDICAL ANIMATION TRANSCRIPT: A surgeon will insert a pacemaker into your body if your hearts conduction system, the electrical system that makes your heart beat, is not working properly. The heart is a muscular organ with four chambers. Blood collects in the hearts two upper chambers, or atria, before filling the two lower chambers, or ventricles. When the ventricles contract, blood in the right ventricle is pumped to the lungs and blood in the left ventricle is pumped to the rest of the body. The heart has a natural pacemaker called the sinoatrial node, or SA node. The pacemaker controls the heart rate by precisely determining when the muscles of the atria and ventricles contract. The electrical signal produced by the SA node reaches the ventricles through a narrow pathway that includes the so called av node and bundle branches. Taken together these pathways are referred to as the conduction system of the heart. Problems with the conduction system can result if the SA node malfunctions, causing the heart to beat too fast, too slow or irregularly. Alternatively, a blockage in the bundle branches can develop, causing the heart to beat more slowly or irregularly. These problems can be due to heart disease, medications or cardiac surgery. Before the procedure, your blood and urine will be tested. You will also have x-rays taken of your chest, and an electrocardiogram, or EKG, will record the electrical activity in your heart. A local anesthetic will be injected into your skin to numb the area where the pacemaker will be inserted. The surgeon will make a small incision beneath your collarbone. The pacemakers leads will be inserted into the subclavian vein and then threaded toward your heart until they reach the right atrium. Your surgeon will view x-ray images on a video screen to position the leads correctly. Once the leads have been tested, they will be connected to the pulse generator. The pulse generator will then be placed in a small pouch that your surgeon will create under the skin beneath your collarbone. Your surgeon will then sew the incision back together. While youre in the hospital, your doctor will monitor your heart rate and blood pressure to be certain the pacemaker is working properly. Before you leave, he or she will make final adjustments to the pacemaker settings. After your procedure, overthe-counter pain medications, such as acetaminophen or ibuprofen, should be sufficient to relieve any pain. You will not be able to drive for about 2 weeks. Periodically, you will need to follow up with your doctor to test and adjust your new pacemaker.