Implantable demand pacemaker.
D000368:Aged; D004562:Electrocardiography; D006327:Heart Block / Q000628:therapy*; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008722:Methods; D008875:Middle Aged; D010138:Pacemaker, Artificial
D007545:Isoproterenol