title: Bifocal demand pacing.
mesh_terms: D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000503:physiopathology / Q000628:therapy*; D002302:Cardiac Output; D004562:Electrocardiography; D004582:Electronics, Medical; D006325:Heart Atria / Q000503:physiopathology; D006327:Heart Block / Q000628:therapy; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D010138:Pacemaker, Artificial; D013997:Time Factors