Certain patients with pacemakers or defibrillators require extraction of their leads (the wires that connect the generator to the heart chambers) due to infection or lead malfunction. For leads that have been in place for long periods of time and that have developed scar tissue around them and extraction may be a difficult, arduous process. Laser technology can be used to assist with removal in such cases. At Columbia, Dr. Frederick Ehlert is an electrophysiologist who has extensive experience in the specialized procedures involving laser lead extraction.