Pacemakers--practice and paradox.
D000368:Aged; D006327:Heart Block / Q000503:physiopathology / Q000628:therapy; D006331:Heart Diseases / Q000628:therapy*; D006801:Humans; D010138:Pacemaker, Artificial / Q000592:standards* / Q000706:statistics & numerical data; D006113:United Kingdom; D014481:United States