The illustration compares an implantable cardioverter defibrillator and a pacemaker. Figure A shows the location and general size of an implantable cardiac defibrillator in the upper chest. The wires with electrodes on the ends are inserted into the heart through a vein in the upper chest. Figure B shows the location and general size of a double-electrode pacemaker in the upper chest. The wires with electrodes on the ends are inserted into the heart through a vein in the upper chest.
