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) in the

AV node The atrioventricular node or AV node electrically connects the heart's atria and ventricles to coordinate beating in the top of the heart; it is part of the electrical conduction system of the heart. The AV node lies at the lower back section of t ...

, and subsequently the rate of electrical impulses in the heart. Positive dromotropy increases

conduction Conductor or conduction may refer to: Music * Conductor (music), a person who leads a musical ensemble, such as an orchestra. * ''Conductor'' (album), an album by indie rock band The Comas * Conduction, a type of structured free improvisation ...

velocity (e.g.

epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ...

stimulation), negative dromotropy decreases velocity (e.g. vagal stimulation). Agents that are dromotropic are often (but not always)

inotropic An inotrope is an agent that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions. Positively inotropic agents increase the strength of muscular contraction. The term ''inotro ...

and chronotropic. For instance,

parasympathetic The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of ...

stimulation is usually negatively chronotropic and dromotropic, but because the vagus nerve does not innervate ventricular myocardium, there is no effect on inotropy. Non-dihydropyridine

calcium channel blockers Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists are a group of medications that disrupt the movement of calcium () through calcium channels. Calcium channel blockers are used as antihypertensive drugs, i.e., as ...

such as verapamil block the slow inward calcium current in cardiac tissues, thereby having a negatively dromotropic, chronotropic and inotropic effect. This (and other) pharmacological effect makes these drugs useful in the treatment of

angina Angina, also known as angina pectoris, is chest pain or pressure, usually caused by insufficient blood flow to the heart muscle (myocardium). It is most commonly a symptom of coronary artery disease. Angina is typically the result of obstr ...

pectoris. Conversely, they can lead to symptomatic disturbances in cardiac conduction and bradyarrhythmias, and may aggravate

left ventricular failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, an ...

References

{{Cardiovascular physiology Cardiovascular physiology

See also

References