Medicine:Dromotropic
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[1]) in the AV node, and subsequently the rate of electrical impulses in the heart.[2][3] Positive dromotropy increases conduction velocity (e.g. epinephrine stimulation), negative dromotropy decreases velocity (e.g. vagal stimulation).[4]
Agents that are dromotropic are often (but not always) inotropic and chronotropic. For instance, parasympathetic stimulation is usually negatively chronotropic and dromotropic, but because the vagus nerve does not innervate ventricular myocardium, there is no effect on inotropy. [citation needed]
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.[5] 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.[6]
See also
- Bathmotropic
- Inotrope
- Catecholamines
References
- ↑ ""AV node; the magnitude of the delay" - Google Search". 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.
- ↑ Furukawa, Y.; Wallick, D. W.; Martin, P. J.; Levy, M. N. (1 May 1990). "Chronotropic and dromotropic responses to stimulation of intracardiac sympathetic nerves to sinoatrial or atrioventricular nodal region in anesthetized dogs". Circulation Research 66 (5): 1391–1399. doi:10.1161/01.RES.66.5.1391. PMID 2335032.
- ↑ Dromotropic at eMedicine Dictionary
- ↑ RPh, Shafinewaz. Toronto Notes for Medical Students Essential Med Notes 2016. https://www.academia.edu/27617864. Retrieved 14 April 2019.
- ↑ "eTG complete". http://etg.hcn.net.au/.
- ↑ "AccessMedicine - Harrison's Internal Medicine: Stable Angina Pectoris". 27 September 2007. http://www.accessmedicine.com/content.aspx?aID=82370&searchStr=calcium+channel+blockers.
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