The use of cardioplegic solutions has significantly improved the safety factor in cardiac operations. It protects the heartbeat by prompt and full diastolic arrest, minimizes the energy requirements of the myocardial and prevents ischemic damage during the arrest stage, and minimizes or prevents injuries to reperfusion when coronary blood flow is restored. This protective effect is primarily responsible because of chemical components added to the cardioplegic solution, such as potassium and glucose.
Myocardial protection is extremely important during organ transplants and open-heart surgeries. The heart must resume its activities as soon as possible at the conclusion of the operation.
Low Potassium Solutions Have Been Preferred for a Long Time
Cardioplegic solutions were used in surgery in the mid-1970s at moderate concentrations of potassium and still are the preferred standard for myocardial defense. Today, most heart surgeries are done through cardiopulmonary bypass using pharmacologic cardioplegic arrest.
The high extracellular potassium level of the cardioplegic solution changes the remaining myocyte membrane potential from -85 mV to between -65 & -40 mV. This change inactivates fast sodium channels blocking the performance of myocardial effects and leading to a “depolarization” arrest.
However, at these higher membrane potentials, an internal non-inactivating sodium window current occurs. The disorder of this disease may cause intracellular sodium load & myocyte calcium overload, leading to contracture and death of the cells.
Prime Choice for Surgeons
Many researchers explored the potential for energy metabolism (indicated by the presence of energy-rich phosphates ATP and ADP) and a return to natural cardiac rhythm in canine hearts retained in solutions like CUSTODIOL® for post-ischemia functions and in particular (as measured by the occurrence of arrhythmia).
Researchers found that the heart preserved in CUSTODIOL® contained much more energy-rich ATP than the heart preserved in other solutions 12 hours after ischemia. As assessed in eight hours and 12 hours of postischemia, CUSTODIOL® treating hearts had much higher ATP/ADP ratios.