ANNOUNCER: A pacemaker is a battery-operated device that is implanted in the chest to help the heart pump blood more effectively. There are different kinds of pacemakers, and it's important to know what they are and what conditions they are used for.
JAMIE B. CONTI, MD: There are a variety of pacemakers that are available. There are single-chamber pacemakers, which means a pacemaker with one wire. Those are used in patients who rarely have a problem, but occasionally need a little bit of extra help keeping their heart rate up.
There are two-chamber pacemakers, which are used for people who in general need considerable support of their heart rate with a pacemaker, and one of those wires goes in the top chamber, the atrium; the other wire goes in the bottom chamber, the ventricle.