located at cardiovascular system tachycardia A heart rate that is abnormally high for age and circumstance (In beats per minute: <1year old: >160; 1 – 2 yrs: >150; 2-5 yrs: >140; 5-12 yrs: >120; >12 yrs: >100) Citation for norms is Don & Roberton; Physical examination; in Practical Pediatrics 2007; 6th ed TachyCard Vaccine 28 (2010) 4487-4498