Sympathetic Nervous System - "Fight or Flight"
o SNS stimulates receptors throughout the body to create "fight or flight response"
o Receptors
Alpha - vessels
Beta 1 - Heart
Beta 2 - Lungs
Beta 1 Receptors
o When stimulated by SNS they cause:
Increase Cardiac Output
Increase HR in SA node (Chronotropic effect)
Increase atrial contractility (Inotropic effect)
Increase conduction and automaticity of AV node
Increase conduction and automaticity of ventricles
Goal of Beta Blocker Therapy
o Goal is to block stimulation of B1 receptors in heart = ↓HR
Common B- Blockers
o Metoprolol
o Esmolol
o Propranolol
Side Effects of B-Blockers
o Bradycardia
o ↓ Blood Pressure
o Bronchoconstriction
o Blood sugar abnormalities
Happy Nursing!
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