Subendocardial myocardial necrosis: a preventable lesion

Area of Science:

• Cardiovascular Surgery
• Cardiac Physiology
• Experimental Pathology

Background:

• Left ventricular subendocardial hemorrhagic necrosis is a significant complication in open-heart surgery, particularly aortic valve replacement.
• This lesion differs from conventional myocardial infarction and contributes to patient morbidity and mortality.
• An established experimental calf model allows for consistent production of this lesion.

Purpose of the Study:

• To evaluate the protective efficacy of hypothermia and Solumedrol infusion against myocardial damage during cardiac surgery.
• To investigate the potential of profound continuous pericardial irrigation with cold Ringer's lactate solution for myocardial protection.

Main Methods:

• Utilized an experimental calf model to induce left ventricular subendocardial hemorrhagic necrosis.
• Compared the effects of systemic hypothermia and Solumedrol infusion versus continuous pericardial irrigation with 4°C Ringer's lactate.
• Assessed myocardial performance and preservation following 40 minutes of left coronary artery occlusion during cardiopulmonary bypass.

Main Results:

• Systemic hypothermia and Solumedrol infusion provided insufficient myocardial protection.
• Profound continuous irrigation of the pericardial cavity with cold Ringer's lactate solution demonstrated excellent myocardial performance and preservation.
• The addition of Solumedrol to pericardial irrigation did not significantly alter the protective effects.

Conclusions:

• Continuous pericardial irrigation with cold Ringer's lactate is a highly effective method for myocardial protection during cardiopulmonary bypass.
• This technique offers superior results compared to systemic hypothermia or Solumedrol infusion alone.
• The positive experimental findings have led to the adoption of this technique in clinical practice.