IMPLANTABLE PACEMAKERS

Advances in cardiac pacing have greatly reduced the size of pacemakers , while improving their longevity and reliability, expanding their cli nical applications and increasing their sophistication in terms of pro gramming and automatic features. Significant reductions in the size of pacing systems have been mainly due to improvements in power sources, increased circuit integration, hybrid packaging, and the development of smaller leads and lead connectors. The use of sophisticated micropr ocessors has transformed some pacemakers into implantable computers. T he incorporation of memory is enabling modern pacing devices to become more like Holter monitors, able to store significant amounts of intra cardiac data. A trend toward the use of sensor technology has been ena bled pacemakers to provide rate response, taking the place of a damage d sinus node.