Cardiac pacing.
D001674:Bioelectric Energy Sources; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D005500:Follow-Up Studies; D006327:Heart Block / Q000401:mortality / Q000628:therapy; D006339:Heart Rate; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D008722:Methods; D009678:Nuclear Energy; D010138:Pacemaker, Artificial / Q000266:history*; D013997:Time Factors