A pacemaker may be implanted whilst a person is awake using local anesthetic to numb the skin with or without sedation, or asleep using a general anesthetic. An antibiotic is usually given to reduce the risk of infection. Pacemakers are generally implanted in the front of the chest in the region of the left or right shoulder. The skin is prepared by clipping or shaving any hair over the implant site before cleaning the skin with a disinfectant such as chlorhexidine. An incision is made below the collar bone and a space or pocket is created under the skin to house the pacemaker generator. This pocket is usually created just above the pectoralis major muscle (prepectoral), but in some cases the device may be inserted beneath the muscle (submuscular). The lead or leads are fed into the heart through a large vein guided by X-ray imaging (fluoroscopy). The tips of the leads may be positioned within the right ventricle, the right atrium, or the coronary sinus, depending on the type of pacemaker required. Surgery is typically completed within 30 to 90 minutes. Following implantation, the surgical wound should be kept clean and dry until it has healed. Care should be taken to avoid excessive movement of the shoulder within the first few weeks to reduce the risk of dislodging the pacemaker leads.