The Arrhythmogenic Actions of Histamine on Human Atrial Fibers

We used standard microelectrode techniques to study the effects of hintamine on right atrial tissues from patients undergoing corrective cardiac surgery. In the 10 to 10 M range, higtamine increased maximum diastolic potential, action potential amplitude, and automaticity. In some preparations, hist...

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Bibliographic Details
Published in:Circulation research 1981-08, Vol.49 (2), p.545-550
Main Authors: LEVI, ROBERTO, MALM, JAMES R, BOWMAN, FREDERICK O, ROSEN, MICHAEL R
Format: Article
Language:English
Subjects:
Action Potentials
Adolescent
Adult
Aged
Arrhythmias, Cardiac - etiology
Child
Child, Preschool
Cimetidine - pharmacology
Epinephrine - pharmacology
Heart Atria - drug effects
Histamine - pharmacology
Humans
Infant
Middle Aged
Myocardial Contraction - drug effects
Propranolol - pharmacology
Verapamil - pharmacology
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Summary:We used standard microelectrode techniques to study the effects of hintamine on right atrial tissues from patients undergoing corrective cardiac surgery. In the 10 to 10 M range, higtamine increased maximum diastolic potential, action potential amplitude, and automaticity. In some preparations, histamine also induced delayed afterdepolarizations and triggered activity. The potency of histamine in increasing automuticity was about 10 times less than that of epinephrine, Propranolol (2 × 10 M), which abolished the chronotropic effect of epinephrine, did not alter the effect of histamine. Conversely, the effect of histamine but not that of epinephrine was antagonized by cimetidine (3 × 10 to 1 × M). This suggests that Hi receptors mediate the chronotropic effects of histamine on the human heart. The slow channel blocker verapamil (2 × 10 to 2 × 10 M) counteracted the effects of histamine on automaticity, delayed afterdepolarizations, and triggered activity, suggesting that in human atrium histamine may act by increasing slow inward (presumably Ca) current. If one considers these arrhythmogenic effects of histamine and the fact that human cardiac tissue contains large amounts of histamine, our experiments lend further support to the concept that histamine release can induce arrhythmias.
ISSN:0009-7330
1524-4571
DOI:10.1161/01.RES.49.2.545