Use of Histidine-Tryptophan Ketoglutarate and St. Thomas Cardioplegia solutions in cardiac surgery: A narrative review

Cardioplegia is the mainstay of myocardial protection in cardiac surgery with cardiopulmonary bypass. Historically, cardioplegia emerged in the late 19th century when scientists discovered that high concentrations of potassium could stop the heart in diastole and that this could be used as an approach in open heart surgery. The most important finding in cardioplegia is that the heart restores its function after cardiac arrest without myocardial damage. In this article, the myocardial protective effects of St Thomas cardioplegia and histidine-tryptophan-ketoglutarate cardioplegia solutions were evaluated in adult cardiac surgery. Both cardioplegia solutions continue to be useful and important in cardiac surgery, but their superiority over each other remains controversial. We also believe that cardiovascular surgeons and perfusionists should focus mainly on the myocardial protective effect in the selection of different cardioplegia solutions. In conclusion, whatever the preferred cardioplegia solution, it should provide basic cardioplegia properties such as preservation of energy stores, rapid diastolic cardiac arrest, reversibility and minimal toxicity.