Discusssion

Since the advent of cardiac surgery, initial administration of cardioplegic solution and cardioplegic reperfusion(s) form a unit being called ‘cardioplegia paradigm’. Particularly in the recent past, operative techniques have been decisively improved so that today very complex myocardial malformations and diseases are surgically treatable. However, such operations require extended ischemic times and consequently more frequent cardioplegic reperfusions are necessary. But there is no discussion that ‘replegia’ is time consuming, inconvenient and harmful (?) in newborns. Now we offer a chance to avoid ‘replegia’ by usage of a highly buffered cardioplegic solution (Custodiol® HTK solution) to combat myocardial acidosis being the main challenge during ischemia. If acidosis is not combatted to a certain extend &hypen; either by ‘replegia’ or by effective extracellular buffering -, anaerobic energy production will be inhibited and therewith progressive cell death will be induced. Effective, high extracellular buffering is only achievable by an ‘intracellular’ (low Na!) cardioplegic solution, which offers the possibility to safely arrest the heart for three hours independent from age, gender, and cardiac disease. On principle, equivalent x-clamp times are feasible with different cardioplegic solutions, however, such solutions must be intermittently (every 20 &hypen; 40 min) applied during ischemia, while HTK solution offers the chance of only a single-shot cardioplegia even with extended x-clamp times. Such methodical approach leads to a paradigm shift. Rationale and clinical results of this solution or myocardial protective method, respectively, will be presented and discussed.