Left ventricular function after preserving the heart for 2 hours at 15 degrees C

Area of Science:

• Cardiovascular Surgery
• Organ Preservation
• Ischemic Heart Disease

Background:

• Effective myocardial protection is crucial for heart transplantation and surgery.
• Standard hypothermia alone offers limited protection for extended preservation periods.
• Investigating novel preservation solutions is vital for improving post-ischemic cardiac function.

Purpose of the Study:

• To evaluate the efficacy of different preservation methods for canine hearts stored for 2 hours at 15°C.
• To compare hypothermia alone, hypothermia with modified solutions (DKS, Collins), intermittent reperfusion, and blood cardiplegia.
• To assess post-preservation cardiac function using an isolated working heart model.

Main Methods:

• Isolated working dog heart model subjected to 2 hours of cold ischemia (15°C).
• Comparison of preservation strategies: hypothermia (H), H + DKS, H + Collins (C), hypoxic hypothermia with reperfusion (H20 + R10), and blood cardiplegia (BC).
• Assessment of left ventricular function via aortic flow resistance and left atrial inflow, determining Starling's curves post-reperfusion.

Main Results:

• Hypothermia alone provided adequate protection for only 1 hour, not 2 hours.
• H20 + R10 and H + C offered some protection but resulted in depressed function and slow recovery, respectively.
• Hearts preserved with hypothermia + DKS (H + DKS) and blood cardiplegia (BC) demonstrated normal function after 2 hours of ischemia; other groups showed edema.

Conclusions:

• DKS solution and blood cardiplegia provide excellent myocardial protection for 2-hour hypothermic heart preservation.
• These methods maintain normal cardiac function post-ischemia, outperforming hypothermia alone and other tested strategies.
• Findings support the clinical application of blood cardiplegia for improved outcomes in cardiac procedures.