Cold blood-diltiazem cardioplegia

Area of Science:

• Cardiology
• Cardiovascular Surgery
• Pharmacology

Background:

• Cold blood-potassium cardioplegia is a standard method for myocardial protection.
• Diltiazem, a calcium channel blocker, has potential as an alternative cardioplegic agent.

Purpose of the Study:

• To evaluate the efficacy and effects of diltiazem in cold blood cardioplegia on myocardial function and metabolism.

Main Methods:

• Canine model undergoing myocardial ischemia with topical ice.
• Coronary perfusion with cold blood containing diltiazem at varying doses and durations.
• Assessment of hemodynamic parameters, myocardial temperature, and high-energy phosphate levels.

Main Results:

• Diltiazem cardioplegia preserved ultrastructure but impaired high-energy phosphate metabolism (ATP, ADP, adenosine pool).
• Group 1 (1-hour ischemia) showed no significant functional changes.
• Group 2 (2-hour ischemia) exhibited slowed heart rate and decreased compliance.

Conclusions:

• Diltiazem cardioplegia offers good functional recovery but negatively impacts myocardial energy metabolism.
• Further research is needed to optimize diltiazem dosage and protocols for cardiac protection.