Effects of cardioplegic solution on human contractile element velocity

Area of Science:

• Cardiology
• Cardiac Surgery
• Myocardial Protection

Background:

• Assessing myocardial protection intraoperatively is crucial for patient outcomes.
• Maximum contractile element velocity (Vpm) is a key indicator of myocardial function.

Purpose of the Study:

• To develop and validate a technique for measuring Vpm.
• To assess the adequacy of myocardial protection during cardiac surgery using Vpm.

Main Methods:

• Developed and employed a Vpm measurement technique in four patient groups: CABG with cardioplegia, CABG with coronary perfusion/ventricular fibrillation, AVR with cardioplegia, and AVR with coronary perfusion.
• Utilized a specific cardioplegic solution (5% dextrose in 0.2% saline at 4°C with KCl and mannitol).

Main Results:

• Patients undergoing CABG with intermittent coronary perfusion and ventricular fibrillation showed a significant decrease in Vpm (p < 0.01).
• Vpm remained unchanged in patients undergoing CABG with cardioplegia.
• Vpm was also unchanged in patients undergoing AVR with either continuous coronary perfusion or cardioplegia.

Conclusions:

• The developed cardioplegic solution provides adequate myocardial protection for up to 105 minutes of aortic clamping.
• Intermittent coronary perfusion during ventricular fibrillation may be detrimental due to coronary blood flow maldistribution.
• Vpm measurement is a valuable tool for intraoperative assessment of myocardial protection.