Myocardial Preservation

Methods to reduce myocardial injury include:

• General
  • Cardiovascular stable anaesthetic
  • Hb 70-100g/dL
  • MAP >65mmHg
  • CPP >50mmHg
  • Low HR
  • Avoid ventricular distension
    ↑ wall tension and VO₂; resolve with venting.
  • Ensure good venous return to reservoir
• Preconditioning
  Exposure to stimulus reduces subsequent ischaemic injury.
  • Ischaemic
  • Pharmacological
    • Halogenated volatiles
    • Xenon
    • Opioids
    • Adenosine
    • β-blockers
    • Lignocaine
    • Nicorandil
• Cardioplegia
  Goal is to maintain electromechanical arrest.
  • Reduces myocardial VO₂ to ~20%
  • Provides O₂ and glucose
  • Multiple types
• Hypothermia
  
  • Reduces O₂ demand
    ~50% per 10°C.
  • Promotes electromechanical arrest

Cardioplegia

Options may include:

• Blood
  Oxygen and buffering capacity.
  • Hb ~50g/dL
• Crystalloid

Reperfusion may be:

• Warm or cold
• Intermittent or continuous

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References