Myocardial protection with cold, ischemic, potassium-induced cardioplegia

Area of Science:

• Cardiovascular Surgery
• Cardiothoracic Anesthesia
• Cardiac Physiology

Background:

• Open-heart surgery necessitates myocardial protection strategies to prevent ischemic damage.
• Cardiopulmonary bypass (CPB) with hypothermia is a common adjunct.
• Potassium-based cardioplegia is widely used to induce cardiac arrest.

Purpose of the Study:

• To evaluate the safety and efficacy of a specific myocardial protection protocol.
• To assess the tolerance of prolonged ischemic arrest during CPB.
• To analyze the correlation between ischemia duration and cardiac rhythm restoration.

Main Methods:

• 204 patients undergoing open-heart surgery with CPB and moderate hypothermia were studied.
• Myocardial protection was achieved using iced, buffered, isoosmolar, potassium-based cardioplegia.
• Aortic cross-clamping was followed by coronary artery perfusion with a potassium-containing solution.

Main Results:

• Prolonged ischemic arrest periods up to 208 minutes were well tolerated.
• Only two of eleven hospital deaths were cardiac-related.
• Spontaneous or single-shock defibrillation was successful in 88% of patients.

Conclusions:

• The employed myocardial protection strategy, including hypothermia and potassium cardioplegia, is safe and effective.
• Extended ischemic times are feasible without significant increase in cardiac mortality.
• The protocol facilitates successful cardiac rhythm restoration post-ischemia.