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Common Congenital Heart Lesions - page 116 / 126

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Pathophysiology:

  • Even in non-Raynaud’s people, the body responds to cold by activating the sympathetic nervous system.

  • Fingers and toes only have α-receptors – which means they can only vasoconstrict in the presence of NE.

  • In healthy people, get moderate vasoconstriction in fingers and toes – in Raynaud’s patients, get severe vasoconstriction (in cold environment or when under emotional stress).

  • Possible mechanisms for overactive/severe vasoconstriction in Primary Raynaud’s:

    • o

      Exaggerated sympathetic discharge in response to cold

      • o

        Heightened vascular sensitivity to adrenergic stimuli

      • o

        Excessive release of vasoconstrictor stimuli (serotonin, thromboxane, endothelin)

  • Possible mechanisms for overactive/severe vasoconstriction in Secondary Raynaud’s:

    • o

      With connective tissue diseases or arterial occlusive diseases, digital lumen is largely obstructed by sclerosis or inflammation Æ higher susceptibility to sympathetically mediated vasoconstriction.

Treatment:

  • Lifestyle…

    • o

      Avoid cold places.

      • o

        Wear warm clothing.

      • o

        If have to be in cold place, use insulated gloves or footwear.

  • Meds…

      • o

        Some success in preventing vasospasm with drugs that relax vascular tone

        • α-adrenergic blockers

        • calcium channel blockers

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