Background: Many steps of myocardial preservation during open heart surgery are practical after the development of the
heart-lung machine. A cardioplegia solution, infused after aortic cross clamping, is an important aspect. Two-thirds of cardioplegia solutions are an intracellular solution (such as HTK or Bretschneider solution) or extracellular solution (such
as blood cardioplegia). Intracellular cardioplegia solution can provide protection for 3-4 hours after one-time infusion, which differs from extracellular cardioplegia solution requiring intermittent use every 20-30 minutes.
Material and Method: Retrospective case-control study in CABG patients were reviewed in Cardiovascular and Thoracic
Unit, Department of Surgery, Khon Kaen University during April 2011and September 2012.The study group was divided into
groups A and B, for myocardial protection by blood cardioplegia and Custodiol-HTK (Histidine-Tryptophan-Ketoglutarate)
solutions. Baseline data such as age, sex, NYHA, risk factors, associated disease, operation, CPB time, aortic cross clamp
time, complication, defibrillation after surgery, ICU stay, length of stay and mortality rate were analyzed.
Results: The study patients in groups A and B were 60 and 65 cases. Defibrillation after finishing CABG in groups A, B was
8.3% and 33.8%. Mortality rate in groups A, B were 1.7% and 4.6%. Other post operative complications were similar in both
groups.
Conclusion: There was significantly more spontaneous ventricular fibrillation after release of cross clamping in HTK group. Clinical outcome of single doses of antegrade, cold Custodiol-HTK cardioplegia solution in CABG surgery protected the myocardium equally well as repetitive antegrade, cold blood cardioplegia.

Keywords: Myocardial protection in coronary artery bypass grafting (HTK versus cold blood cardioplegia)