• Journal of Chest Surgery
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• v.20 no.2
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• pp.230-240
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• 1987

Cardioplegia and myocardial protection were performed under cardiopulmonary bypass during open-heart surgery with the use of cold St. Thomas Hospital cardioplegic solution [4=C] for the coronary artery perfusion and normal saline solution [4- C] for the topical cardiac cooling. To maintain the state of myocardial protection, coronary artery reperfusion was carried out using St. Thomas Hospital cardioplegic solution at the interval of 30 minutes. A total number of patients studied were 57 cases, including 37 cases of correction for congenital cardiac anomalies and 20 cases for acquired heart valvular diseases. Cardiopulmonary bypass time during the surgery was observed to be average of 87.89*47.55 hours, aortic cross-clamping time to be average of 76.68~44.27 hours raging from 30 to 191 minutes. In order to evaluate the effects of myocardial protection in the surgery, serum enzyme levels were determined. To observe the relationship between aortic cross-clamping time and myocardial protection effects, patients studied were divided into the following 3 groups. I group: aortic cross-clamping time, 60 minutes, II group: aortic cross-clamping time, 90 minutes, III group: aortic cross-clamping time, over 91 minutes. 1. Changes in serum enzyme levels in postoperative period. [1] SCOT; The postoperative value [increased over 200 units] for ischemic myocardial injury during operation was observed in 11 cases [19.3% of the total] of the total patients studied, of which 4 cases [13.3%] in I group, 1 case [10.0%] in II group, and 6 cases [35.3%] in III group. [2] LDH; The positive value [increased over 900 units] for ischemic myocardial injury during operation was observed in 9 cases [15.7% of the total] of the total patients studied, of which 2 cases [6.6%] in I group, 1 case [10.0%] in II group, and 6 cases [35.3%] in III group. [3] CPK; The positive value [increased over 800 units] for ischemic myocardial injury during operation was observed in 10 cases [17. 5% of the total] of the total patients studied, including 4 cases [13. 3%] in I group, 1 case [10.0%] in II group, and 5 cases [29.4%] in III group. 2. The myocardial protection method used in the present study was demonstrated to be effective for the myocardial protection in the surgery with aortic cross-clamping time of up to 90 minutes. A few ischemic myocardial injury were observed in the surgery with aortic cross-clamping time over 91 minutes, but no significant cardiac dysfunction was noted. The surgery with aortic cross-clamping time of up to 191 minutes did not appear to give rise any significant interference with postoperative recovery.

• Journal of Chest Surgery
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• v.22 no.2
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• pp.225-233
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• 1989

Cardioplegia and myocardial protection were performed under cardiopulmonary bypass during open heart surgery with the use of St. Thomas Hospital cardioplegic solution [4 [C] for the coronary artery perfusion and normal saline solution [4[ c] for the topical cardiac cooling. To maintain the state of myocardial protection, coronary artery reperfusion was carried out using St. Thomas Hospital cardioplegic solution at the interval of 30 minutes. A total number of patients studied were 57 cases, including 37 cases of correction for congenital anomalies and 20 cases for acquired heart diseases. Cardiopulmonary bypass time during the surgery was observed to be average of 87.89*47.55 hours, aortic cross-clamping time [ACCT] to be average of 76.68*44.27 hours raging from 30 to 191 minutes. In order to evaluate the effects of myocardial protection in the surgery, serum enzyme levels were determined. To observe the relationship between ACCT and myocardial protection effects, patients studied were divided into the following 3 groups. I group: ACCT 60 minutes, II group: ACCT 90 minutes, III group: ACCT over 91 minutes [1] SGOT; The positive value [increased over 200 units] for ischemic myocardial injury during operation was observed in 11 cases [19.3% of the total] of the total patients studied, of which 4 cases [13.3%] in I group, 1 case [10.0%] in II group, and 6 cases [35.3%] in III group. [2] LDH; The positive value [increased over 900 units] for ischemic myocardial injury during operation was observed in 9 cases [15.7% of the total] of the total patients studied, of which 2 cases [6.6%] in I group, 1 case [10.0%] in II group and 6 cases [35.3%] in III group. [3] CPK; The positive value [increased over 800 units] for ischemic myocardial injury during operation was observed in 10 cases [17.5% of the total] of the total patients studied, including 4 cases [13.3%] in I group, 1 case [10.0%] in II group, and 5 cases [29.4%] in III group [4] The myocardial protection method used in the present study was demonstrated to be effective for the myocardial protection in the surgery with ACCT of up to 90 minutes. A few ischemic myocardial injury were observed in the surgery with ACCT over 91 minutes, but no significant cardiac dysfunction was noted. The surgery with ACCT of up to 191 minutes did not appear to give rise any significant interference with postoperative recovery.

• Journal of Chest Surgery
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• v.31 no.2
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• pp.95-101
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• 1998

Ischemic preconditioning is known to have protective effect on myocardial function at prolonged ischemic insult but the mechanism of the effect is not clearly known. The effect of the preconditioning on the global ischemia using cardioplegic solution is not well known. To evaluate the effect of global myocardial preconditioning on the functional recovery after cardioplegic arrest and two hours of hypothermic storage, we used the isolated rat heart and two hours cardioplegic arrest time at $0^{\circ}C$. In the experimental group(n=10), after baseline functional data was obtained, ischemic preconditioning was induced with 1 min of global normothermic ischemia for three times before the arrest period. In the control group(n=10), hearts underwent no ischemic precondi- tioning. After 2 hrs of cardioplegic arrest and storage in the $0^{\circ}C$ cardioplegic solution reperfusion was done and hemodynamic data were collected at post-reperfusion 20 min. Heart with ischemic preconditioning showed improved functional recovery at post reperfusion 20 min in peak developed pressure and dP/dT. In percent change of the peak pressure, preconditioning group showed 93.20$\pm$15.7% recovery rate compared to baseline data, and control group showed 67.3$\pm$15.6% recovery rate. In percent change of the dP/dT, control group showed 54.7$\pm$18.2% recovery rate and preconditioning group showed 78.1$\pm$15.1% recovery rate. Percent changes in heart rate and coronary flow showed no significant difference between two groups and there was no significant differences in amount of cardioplegic delivery between groups. Our data suggest ischemic preconditioning may have protective effect on recovery state after cardioplegic arrest and 2 hr ischemic storage of isolated rat heart and its mechanism is not related to the amount of the cardioplegic delivery amount.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1076-1080
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• 1996

The results about the myocardial protection of recta of the nitric oxide precursor L-arginine upon reperrusion injury after ischemia are diverse. These diversities may be model dependent. Experiments were designed and performed to investigate myocardial protection effects according to the concentration of L-arginine. The Isolated rat hearts were subjected in a 30 minutes oi normothermic ischemia and reperfused for 30 minutes with reperfusate containing 0, 1, 2, 3, 4 moil L-arginine. After 30 minutes of reperfusion, group with 1 and 2 mM/L L-arginine showed a trend of better recovery in left ventricular systolic function(left ventricular developed pressure, positive maximum dpfdt), diastolic function(negative maximum dpfdt) and coronary flow compared to control group(reperfusate no L-arginine). Recovery was impaired with a higher concentration, and at 4 moil L-arginine r covery was worse than control(p (0, 05). These results suggest that optimal concentration of L-arginine Is Important or the recovery of myocardial and endothelial function after ischemia and reperfusion.

• Journal of Chest Surgery
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• v.23 no.4
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• pp.646-653
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• 1990

Currently numerous methods are in use for myocardial protection from the ravages of ischemia and hypoxia. This study was designed to compare with FDP-GIK[Group II, n=8] and GIK cardioplegic solution[Group I, n=8] in ability of myocardial protection and was examined in the isolated working rat heart subjected to long period[120 min] of hypothermic[10 - 15K] ischemic arrest with multidose[every 30 min] cardioplegic infusion. During postischemic reperfusion period 20 min, hemodynamic functions[aortic flow, coronary flow, peak aortic pressure, cardiac output, heart rate], biochemical enzymatic & electrical activities were evaluated. The time from onset of reperfusion to the return of regular sinus rhythm was significantly reduced from 87$\pm$3 sec to 17$\pm$2 sec[P<0.05]. The postischemic recovery of aortic flow was better in the group II [95.1$\pm$3.3% of its preischemic control level] than in the Group I [75.4$\pm$6.8%] [P<0.05]. Cardiac output and stroke volume was also better in the group[91.3$\pm$1.6%, 89.4$\pm$2.6%, respectively] than in the Group I [79.1$\pm$3.7%, 77.0$\pm$4.8%, respectively] [P<0. 05]. Creatine kinase leakage was also significantly reduced from 33.8$\pm$4.9 IU /10 min / gm * dry weight to 15.4$\pm$3.6 IU /10 min /gm * dry weight[P<0.05]. It is suggested that adding FDP to GIK cardioplegic solution improves its ability to protect the heart against long period of hypoxic ischemia.

• Journal of Chest Surgery
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• v.26 no.2
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• pp.75-79
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• 1993

Myocardial protection against ischemic and reperfusion injuries is still in troublesome eventhough couples of the way of myocardial protection have been applied since 1970's. One of the possibility in myocardial protection is adding Fructose-l,6-diphosphate(FDP) in cardioplegic solution. It is assumed that FDP can promote ATP production under anaerobic condition as well as inhibiting the supressing effect of lactate on phosphofructokinase. We compared the myocardial protecting effects of FDP in crystalloid cardioplegic solution (St. Thomas formula, 10$^{\circ}C$, pH = 7.4) and reperfusate using isolated rat hearts in modified Langendorf apparatus by the parameters of preischemic and post reperfusing heart rate, time to first beat, occurance of arrhythmia, time to stabilization, and the rate of left ventricular pressure developing. Group A (n = 10), containing no FDP in cardioplegic and reperfusing solutions was control. Group B (n = 5), containing FDP in cardioplegic solution, showed statistically significant superiority of postischemic left ventricular pressure development than the control group. Group C (n = 5), containing FDP in reperfusate, showed statistically significant myocardial depressing effect than the controls. Other parameters were unremarkable. The cause is uncertain, but it is assumed that the negative feedback inhibition of FDP in energy metabolism or unknown blocking effect of FDP on certain transmembrane ionic currents is present. In conclusion, 1) FDP in cardioplegic solution has beneficial effect on postischemic left ventricular preservation. 2) FDP is strong acid when is hydrolyzed, so precise acid titration is neccessary. 3) FDP in reperfusate has negative left ventricular preservation, otherwise the mechanism is still uncertain.

• Journal of Chest Surgery
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• v.33 no.8
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• pp.630-637
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• 2000

Backgroud: There are well-known problems in the management of low weight neonates or infants with congenital heart defects. In the past, because of a perceived high risk of operations using cardiopulmonary bypass(CPB) in these patients, there was a tendency for staged palliation without the use of CPB. However, the recent trend has been toward early reparative surgery using CPB, with acceptable mortality and good long-term survival. Therefore we reviewed our results of the operations in infants weighing less than 3kg and considered the technical aspect of conducting the CPB including myocardial protection. Material and Method: Between Jan. 1995 and Jul. 1998, 28 infants weighing less than 3kg underwent open heart surgery for many cardiac anomalies with a mean body weight of 2.7kg(range; 1.9-3.0kg) and a mean age of 41days(range; 4-110days). Preoperative management in the intensive care unit was needed in 20 infants and preoperative ventilator support therapy in 11. Total correction was performed in 23 infants and the palliative procedure in 5. Total circulatory arrest was needed in 11 infants(39%). Result: There were seven hospital deaths(25%) caused by myocardial failure(n=3), surgical failure(n=2), multiorgan failure(n=1), and sudden death(n=1). The median duration of hospital stay and intensive care unit stay were 13days(range; 6-93days) and 6days(range; 2-77days) respectively. The follow-up was achieved in 21 patients and showed three cases of late mortality(15%) and a one-year survival rate of 62%. No neurologic complications such as clinical seizure and intracranial bleeding were noticed immediately after surgery and during follow-up. Conclusion: The early and late mortality rate of open heart surgery in our infants weighing less than 3 kg stood relatively high, but the improved outcomes are expected by means of the delicate conduct of cardiopulmonary bypass including myocardial protection as well as the adequate perioperative management. Also, the longer follow-up for the neurologic development and complications are needed in infants undergoing circulatory arrest and continuous low flow CPB.

• Journal of Radiation Protection and Research
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• v.47 no.1
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• pp.22-29
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• 2022

Background: A comprehensive, traceable, and easy-to-understand radiation risk indicator is desired for radiological protection. The early-onset hypothesis could be used for this purpose. Materials and Methods: An indicator for early death (IED) was developed and calculated using the epidemiological dataset from the 14^th Report of the Life Span Study (LSS) of Hiroshima and Nagasaki. By clarifying the calculation process, IED for all-cause mortality was estimated. In addition, the characteristics of IED for solid cancer mortality and cardiovascular mortality as well as those of men and women, and their dependence on age at exposure were investigated for detailed analysis. Results and Discussion: The IED for all-cause mortality was estimated to be approximately 4 years for an acute radiation exposure of 1 Gy regardless of the fitting dose range. The cumulative death rate for all solid cancers also indicated the early-death tendency (approximately 7-10 years at 1 Gy). Although, there is a slight difference in the characteristics of the risk obtained from the LSS study and this study, it is considered that the IED in a unit of years can also be used to show the overall picture of risk due to radiation exposure. Conclusion: We developed and calculated the indicator for early death, IED, for the cumulative mortality rate of all causes of death, all solid cancers, and circulatory diseases. The quantitative values of IED were estimated to be 4 years for all causes of death, 7-10 years for all solid cancers. IED has an advantage for intuitively understanding the meaning of radiation risk since it can be obtained by a simple and traceable method.

• Journal of Chest Surgery
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• v.35 no.7
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• pp.523-529
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• 2002

Background: Previous reports present that the early results of coronary artery bypass grafting (CABG) has been improving with the accumulation of surgical experience. We conducted a retrospective analysis of the patients who received CABG to evaluate the recent results of CABG. Material and Method: Between January 1996 and August 2001, 154 patients underwent CABG at Hanyang University Hospital. There were 47 patients(group I) who were operated between 1996 and 1998, and 107 patients(group II) who were operated thereafter. The preoperative diagnosis, operative procedure, mortality, and complications were analyzed retrospectively. Result: There were 35 males and 12 females in group I, and 78 males and 29 females in group II, which shows similar ratio of sexes between the two groups. The average age of patients for group I and group II was $55.9{\pm}6.2$ years and $61.0{\pm}8.0$ years, respectively, showing a significant increase in group II(p<0.05). The average left ventricular ejection fraction(LVEF) for group I and group II was $54.6{\pm}11.8$% and $56.9{\pm}13.0$%, respectively. The number of patients who had previous MI in group I and group II were 13 patients(27.7%) and 14 patients(13.1%), respectively, which shows a significant difference (p<0.05). All procedures were performed using the cardiopulmonary bypass(CPB) and moderate systemic hypothermia. Myocardial protection was achieved using intermittent hypothermic ischemia under ventricular fibrillation state or cold crystalloid cardioplegic solution for most of group I patients, whereas cold blood cardioplegic solution was used for group II patients. The mean CPB times for group I and group II were $149.2{\pm}48.7$ minutes and $113.1{\pm}30.6$ minutes, respectively. The mean aortic cross clamp times for group I and group II were $81.3{\pm}26.5$ minutes $72.2{\pm}23.9$ minutes, respectively. These figures show that CPB and aortic cross clamp times were significantly reduced in group II(p<0.05). The use of the left internal thoracic artery(LITA) was increased from 42%(20/47) for group I to 81% (87/107) for group II. The mean number of grafts also significantly increased from $2.5{\pm}0.6$ for group I to $3.0{\pm}1.1$ for group II(p<0.05). Intra-aortic balloon pump(IABP) was applied in 7 cases in group I and 17 cases in group II. Of these, 28.6%(2/7) and 52.9%(9/17) were broadly applied preoperatively in patients with LVEF<40% or congestive heart failure. The operative mortalities for group I and II were 10.6%(5/47) and 0.9%(1/107), respectively, which shows significant decrease for group II(p.0.05). Conclusion: This report suggest that CABG using CPB can recently be performed more safely in virtue of the accumulation of surgical experience with reduction in CPB and aortic cross clamp times and improved surgical techniques and myocardial protection. And we think that the optimal treatment of patients with left ventricular dysfunction associated with congestive heart failure and the extended application of IABP, especially have contributed to the reduction of operative mortality and morbidity.

• Journal of Chest Surgery
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• v.13 no.4
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• pp.394-404
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• 1980

During the period of June 1976 October 1980 131 cases of Open heart Surgery was performed at the National Medical Center in Seoul under the extracorpocal circulation. 77 cases were congenital heart disease and 54 were acquired heart disease. The age of the patients ranged between 2$\frac{1}{2}$ and 51 years. For all patients partial hemodilution technique and moderte hypothermia was used during extracorporeal circulation and cardioplegia was done for myocardial protection since April 1978. 41 of congenital cases were non-cyanotic group and 1 case died. 36 of congenital cases were cyanotic group and revealed very high mortiality rate (16 death, 39%). 53 of acquired cases were cases of valvular heart disease, 34 mitral (3 death), 1 aortic, 4 mitral with aortic 12 mitral with tricuspid (3 death), 2 triple valves (2 death), and revealed mortality rate of 15.1% (8 death). 1 of acquired cases were left atrial myxoma. There were 25 cases of operative death and over all motality rate was 19.1%.