dromotropic
{{Short description|Agent affecting the delay in the AV node}}
The term dromotropic derives from the Greek word δρόμος drómos, meaning "running", a course, a race. A dromotropic agent is one which affects the conduction speed (in fact the magnitude of delay{{cite web|url=https://www.google.ca/search?q=%22AV+node;+the+magnitude+of+the+delay%22&rlz=1C1CHBF_enCA805CA806&oq=%22AV+node;+the+magnitude+of+the+delay%22&aqs=chrome..69i57.6085j0j1|title="AV node; the magnitude of the delay" - Google Search|website=www.Google.ca|access-date=14 April 2019}}) in the AV node, and subsequently the rate of electrical impulses in the heart.{{cite journal|last=Furukawa|first=Y.|author2=Wallick, D. W. |author3=Martin, P. J. |author4= Levy, M. N. |title=Chronotropic and dromotropic responses to stimulation of intracardiac sympathetic nerves to sinoatrial or atrioventricular nodal region in anesthetized dogs|journal=Circulation Research|date=1 May 1990|volume=66|issue=5|pages=1391–1399|doi=10.1161/01.RES.66.5.1391|pmid=2335032|doi-access=free}}[http://www.emedicinehealth.com/script/main/srchcont_dict.asp?src=Dromotropic Dromotropic] {{Webarchive|url=https://web.archive.org/web/20170410050717/http://www.emedicinehealth.com/script/main/srchcont_dict.asp?src=dromotropic |date=2017-04-10 }} at eMedicine Dictionary
Positive dromotropy increases conduction velocity (e.g. epinephrine stimulation), negative dromotropy decreases velocity (e.g. vagal stimulation).{{cite web|url=https://www.academia.edu/27617864|title=Toronto Notes for Medical Students Essential Med Notes 2016|first=Shafinewaz|last=RPh|access-date=14 April 2019|via=www.Academia.edu}}
Non-dihydropyridine calcium channel blockers such as verapamil block the slow inward calcium current in cardiac tissues, thereby having a negatively dromotropic, chronotropic and inotropic effect.{{cite web|url=http://etg.hcn.net.au/|title=eTG complete|website=HCN.net.au|access-date=14 April 2019|archive-url=https://web.archive.org/web/20070214101454/http://etg.hcn.net.au/|archive-date=14 February 2007|url-status=dead}} This (and other) pharmacological effect makes these drugs useful in the treatment of angina pectoris. Conversely, they can lead to symptomatic disturbances in cardiac conduction and bradyarrhythmias, and may aggravate left ventricular failure.{{cite web|url=http://www.accessmedicine.com/content.aspx?aID=82370&searchStr=calcium+channel+blockers|archive-url=https://web.archive.org/web/20070927003933/http://www.accessmedicine.com/content.aspx?aID=82370&searchStr=calcium+channel+blockers|url-status=dead|archive-date=27 September 2007|title=AccessMedicine - Harrison's Internal Medicine: Stable Angina Pectoris|date=27 September 2007|access-date=14 April 2019}}