Competitive rhythms with synchronous standby (demand) pacemakers.
D000368:Aged; D005260:Female; D006327:Heart Block / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D013614:Tachycardia, Paroxysmal / Q000628:therapy*; D013997:Time Factors