tachycardia

1. (medicine, cardiology) A rapid resting heart rate, especially one above 100 beats per minute; palpitations.Examples: "The heart becomes irritable, there is nervous palpitation, or attacks of paroxysmal tachycardia."; "Tachycardias of all types reduce the cardiac output if the rate is high enough. […] The main difference between the tachycardias as regards the reduction of cardiac output is the rate at which they cause a significant reduction of cardiac output, and this depends on the type of tachycardia."; "Tachycardia is defined as a FHR [fetal heart rate] above 160 bpm that lasts for at least 10 minutes. Tachycardia represents increased sympathetic and decreased parasympathetic autonomic tone and, therefore, is generally associated with a normal loss of FHR baseline variability[…]."Synonyms: tachyrhythmiaAntonyms: bradycardiacountableuncountable