What is Tachycardia?
{{Infobox symptom | Name = Tachycardia | Image = Tachycardia_ECG_paper.svg | Caption = ECG showing [[sinus tachycardia]] with a rate of about 100 beats per minute | DiseasesDB = | ICD10 = {{ICD10|I|47||i|30}}-{{ICD10|I|49||i|30}}, {{ICD10|R|00|0|r|00}} | ICD9 = {{ICD9|427}}, {{ICD9|785.0}} | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = | eMedicineTopic = | MeshID = D013610 }} '''Tachycardia''' is the fast beating of the [[heart]]. In [[adult]]s, it refers to [[heart rate]]s higher than 100 beats per minute. Tachycardia may be a normal physiological response to [[wikt:stress|stress]], but depending on the cause and how healthy the patient is, tachycardia could be harmful and need medical treatment. In some cases, tachycardia can cause [[death]]. Tachycardia can be harmful in two ways. First, when the heart beats too rapidly, it may perform inefficiently. Second, the faster the heart beats, the more [[oxygen]] and nutrients the heart requires. This can be especially problematic for patients suffering from [[ischaemic heart disease]]. {{biology-stub}} [[Category:Medical emergencies]] [[Category:Cardiovascular system]]