Transplanted Heart
Considerations
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Altered physiology of the denervated heart:
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Preload dependent
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High resting heart rate & loss of vagal tone
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Delayed sympathetic response to circulating catecholamines
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Dysrhythmias & conduction abnormalities → permanent pacemaker in 5%
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Altered pharmacology of the transplanted heart:
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Ineffective indirect-acting agents (e.g. ephedrine, atropine)
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Intact response to direct-acting vasoactive drugs (e.g. epinephrine, isoproterenol)
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Allograft function:
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Rejection
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Arrythmias
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Coronary vasculopathy (accelerated CAD): silent ischemia secondary to denervation
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Co-morbidities:
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Hypertension (90%)
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Diabetes
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Renal dysfunction
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Malignancy
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Steroid therapy: will require stress dose
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Immunosuppressive therapy:
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↑ risk of infection & need for strict sterile technique
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Adverse effects: anemia, thrombocytopenia, hepatotoxicity, nephrotoxicity
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Goals
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Hemodynamic goals:
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Preload: maintain normal or high (CO increases by increasing stroke volume)
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Rhythm: avoid pro-arrhythmic states
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Afterload: maintain perfusion to potentially ischemic myocardium
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Use direct-acting sympathomimetics (isoproterenol & epinephrine must be available)
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Avoid infection: strict sterile technique & minimize catheters/invasive devices
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Thorough review of functional capacity, investigations (echo, biopsies for graft dysfunction)
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Strongly consider consultation with transplant clinic & cardiology pre-operatively
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If valvulopathy: needs infective endocarditis prophylaxis
Pregnancy Considerations
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Same goals as above apply
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Epidural is very good technique
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Ensure adequate intravascular volume
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Extra attention to aseptic techniques