Cardiac Performance, Dr. D. Penney




Actions of Vagal Parasympathetic Neurons to the Heart (through release of acetylcholine)

...... Site ................................ Action .......................................... Affecting ......

  • sino-atrial node ................... decreases heart rate ................................ chronotropicity

  • atrial myocardium ................ decreases atrial force .............................. inotropicity

  • atrio-ventricular node ............ slowed AV conduction ............................ chronotropicity

  • atrio-ventricular node ............ delayed conduction / increased refractoriness ... chronotropicity


    Note: There are few/no parasympathetic nerve endings on the ventricular myocardium, so while acetylcholine is a potential negative inotrope for the ventricles, it is not released there.



    Last changed 02/17/03


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