Right ventricular function after normothermic versus hypothermic cardiopulmonary bypass

Area of Science:

• Cardiovascular Surgery
• Cardiac Anesthesia
• Myocardial Preservation

Background:

• Normothermic systemic perfusion during cardiopulmonary bypass may hinder myocardial hypothermia, essential for ventricular preservation.
• The right ventricle is considered particularly vulnerable to rewarming during cardiac procedures.

Purpose of the Study:

• To prospectively evaluate myocardial rewarming and right ventricular function in patients undergoing coronary artery bypass grafting.
• To compare outcomes between moderate hypothermic and normothermic perfusion strategies.

Main Methods:

• 30 patients with significant right coronary artery stenosis were randomized to hypothermic or normothermic perfusion.
• Right ventricular function was assessed using a specialized catheter measuring ejection fraction and stroke work index.
• Multidose cold blood cardioplegia was administered to maintain electromechanical arrest in all patients.

Main Results:

• Normothermic bypass led to greater myocardial rewarming compared to hypothermic bypass.
• The right ventricle showed no increased susceptibility to rewarming compared to other cardiac regions.
• No significant differences in right ventricular function were observed between the two groups at any study point.

Conclusions:

• Moderate myocardial rewarming during normothermic perfusion does not compromise right ventricular preservation.
• Right ventricular function remained preserved and equivalent to baseline in patients with right coronary artery disease undergoing revascularization.