Normothermic blood cardioplegia. Alternative or adjunct?

Area of Science:

• Cardiovascular Surgery
• Cardiothoracic Medicine
• Myocardial Protection Strategies

Background:

• Normothermic blood cardioplegia was initially developed as an adjunct to hypothermic methods for myocardial protection during cardiac surgery.
• Its clinical introduction followed extensive experimental validation.
• Continuous normothermic blood cardioplegia without hypothermia has recently gained interest due to its simplicity and promising initial outcomes, despite a lack of robust scientific infrastructure.

Purpose of the Study:

• To clarify the role of normothermic blood cardioplegia as an adjunct, not a replacement, for existing hypothermic cardioprotective techniques.
• To address the misconception that continuous coronary perfusion prevents all ischemia.
• To highlight limitations and unanswered questions surrounding continuous warm retrograde blood cardioplegia.

Main Methods:

• Review and analysis of existing literature and clinical data on normothermic blood cardioplegia.
• Identification of theoretical and practical limitations through experimental testing.
• Discussion of clinical observations and potential pitfalls of continuous warm retrograde blood cardioplegia.

Main Results:

• Normothermic blood cardioplegia functions best as an adjunct to established hypothermic cardioprotection methods.
• "Unintentional ischemia" can occur even with continuous coronary perfusion.
• Continuous warm retrograde blood cardioplegia has demonstrated theoretical and practical limitations.

Conclusions:

• Normothermic blood cardioplegia should be viewed as an adjunct to, rather than an alternative to, hypothermic cardioprotection.
• Continuous coronary perfusion does not inherently eliminate the risk of myocardial ischemia.
• Further research is needed to address limitations and unanswered questions regarding continuous warm retrograde blood cardioplegia, advocating for a flexible, combined approach to cardioprotection.