cardiotonic

cardiotonic /car·dio·ton·ic/ (kahr″de-o-ton´ik) having a tonic effect on the heart; an agent that so acts.

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car·di·o·ton·ic (kärd--tnk)

adj.

Relating to or having a favorable effect upon the action of the heart.

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cardi·o·tonic n.

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cardiotonic

[kär′dē·ōton′ik]

Etymology: Gk, kardia + tonos, tone

1 pertaining to a substance that tends to increase the efficiency of contractions of the heart muscle.

2 a pharmacologic agent that increases the force of myocardial contractions. Cardiac glycosides, derived from certain plant alkaloids, exert a tonic effect by altering the transport of electrolytes across the myocardial membrane, causing a decreased efflux of sodium and calcium and a decreased influx of potassium. Digitoxin and digoxin, widely used cardiac glycosides obtained from leaves of a species of foxglove, increase the force of myocardial contractions, extend the refractory period of the atrioventricular node, and, to a lesser degree, affect the sinoatrial node and the heart's conduction system.

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cardiotonic [kahr″de-o-ton´ik]

1. having a tonic effect on the heart.

2. an agent that so acts.

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cardiotonic,

adj/n property of a substance that has an invigorating effect on the heart.

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cardiotonic

having a tonic effect on the heart; an agent that so acts.

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cardiotonic

adjective Referring to a tonic effect on the heart noun An agent with said effect–eg, digitalis