[Clinical study on the ideal temperature of blood cardioplegic solution in coronary artery bypass graft surgery]

The effect of myocardial protection in coronary artery bypass graft surgery was evaluated from enzymatic examination and cardiac function to clarify the ideal temperature of blood cardioplegic perfusate (BCP). The surgical cases were divided into two groups from the temperature of BCP; 8 degrees C BCP in 64 cases (Group I) and 20 degrees C BCP in 64 cases (Group II). Peak total creatine-Kinase (CK) and CK-MB fraction were significantly elevated in Group I than in Group II. The value of CK-MB was 79 +/- 79 IU/L in Group I and 37 +/- 26 IU/L in Group II (p < 0.01). The parameters of cardiac function were measured from radio-isotope (RI) ventriculography in the 35 cases with depressed ejection fraction and elevated left ventricular end-diastolic pressure (17 cases in Group I and 18 cases in Group II). Postoperative parameters such as ejection fraction, first third ejection fraction, peak ejection rate and early diastolic peak filling rate improved more significantly than preoperative values in Group II, although these parameters did not improve in Group I. From these results, 20 degrees C BCP provided excellent myocardial protection to arrested heart during coronary artery bypass surgery probably because of decreased viscosity of BCP and adequate oxygen carrying capacity to myocardium.