• Journal of Chest Surgery
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• v.29 no.6
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• pp.639-645
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• 1996

A 14-year-old male patient with previous surgical repair of tetralogy of Fallot was admitted with hemodynamically significant ventricular tachycardia (VT). On preoperative electrophysiologic study (EPS), the morphology of documented VT was RBBB of vertical axis with 320 msec cycle length. The endocardial mapping during VT delineated the origin of VT at right ventricular outflow tract (RVOT), where the patch was attached. The clinical VT had a clockwise reentry circuit around the patch with the earliest activation at the same site seen during the preoperative EPS. The previously placed right ventricular outflow patch and fibrous tissue were removed. During a postoperative EPS, it was no longer possible to induce the VT. Ventricular tachycardia following repair of tetralogy of Fallot seen in this patient was caused by a macro-reentry around the right ventricular outflow patch. We were able to ablate the VT with the aid of a detailed mapping of its epicardial activation sequence.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.199-207
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• 1996

Ischemic myocardial damage is inevitable to cardiac surgery. Myocardial damage after initiation of reperfusion through the coronary arteries is one of the most important determinants of a successful surgery. Adenosine is a potent vasodilator, and is also known to induce rapid cardioplegic arrest by its property of antagonizing cardiac calcium channels and activating the potassium channel. Thus, we initiated this study with adenosine to improve postischemic recovery in the isolated rat heart. We tested the hypothesis that adenosine could be more effective than potassium in inducing rapid cardiac arrest and enhancing postischemlc hemodynamic recovery. Isolated rat hearts, connected to the Langendorff appratus, were perfused with Krebs-Henseleit buffer and all hearts were subjected to arrest for 60 minutes. Three groups of hearts were studied according to the composition of cardioplegic solutions : Group A (n=10), adenosine 10mmo1/L+potassium free modified St. Thomas cardioplegia : Group B (n=10), adenosine 400mo1/L+S1. Thomas cardioplegia:Group C(control, n=10), St. Thomas cardioplegia. Adenosine-treated groups (group A & B) resulted in more rapid cardiac arrest than control group (C) (p< 0.01). There was greater improvement in recovery of coronary blood flow at 20 and 30 minutes of reperfusion in group A and at 20 minutes in group B when compared with control group(p<0.01). Recovery of systolic blood pressure at 10 minutes after reperfusion in group A and B was significantly superior to that in group C (p<0.01). Recovery of dp/dt at 10 minute after reperfusion in group A was also significantly superior to group C (p<0.05). Group A and B showed better recovery rates than control group in aortic blood flow, cardiac output, and heart rate, but there were no statistical differences. CPK levels of coronary flow in group A were significantly low (p< 0.01). We concluded that adenosine-enriched cardioplegic solutions have better effects on rapid cardiac arrest and postischemic recovery when compared with potassium cardioplegia.

• Journal of Chest Surgery
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• v.39 no.11 s.268
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• pp.815-821
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• 2006

Background: Carotid endarterectomy is an effective treatment modality in patients with severe carotid artery stenosis, but it may result in serious postoperative complications, We analyzed the results of the carotid endarterectomy performed in our institution to reduce the complications related to the card endarterectomy. Material and Method: We analyzed retrospectively the medical records of 74 patients(76 cases) who underwent carotid endarterectomy for carotid artery stenosis by a single surgeon from February 1996 to July 2004. Result: There were 64 men and 10 women. The mean age of the patients was 63.6 years old. Carotid endarterectomy only was performed in 63 cases, carotid endarterectomy with patch angioplasty in 8 cases, and carotid endarterectomy with segmental resection of internal carotid artery and end to end anastomosis in 5 cases. Intra-arterial shunt was used in 29 cases. The mean back pressures of internal carotid arteries checked after clamping common carotid arteries and external carotid arteries were $23.48{\pm}10.04$ mmHg in 25 cases with changes in electroencephalography(group A) and $47.16{\pm}16.04$ mmHg in 51 cases without changes in electroencephalography(group B). There was no statistical difference in the mean back pressure of internal carotid arteries between two groups(p=0.095), but the back pressures of internal carotid arteries of all patients with changes in electroencephalography were under 40 mmHg. When there was no ischemic change of electroencephalography after clamping common carotid artery and external carotid artery, we did not make use of intra-arterial shunt regardless of the back pressure of internal carotid artery. Operative complications were transient hypoglossal nerve palsy in four cases, cerebral hemorrhage occurred at previous cerebral infarction site in two cases, mild cerebral infarction in one case, hematoma due to anastomosis site bleeding in one case, and upper airway obstruction due to laryngeal edema probably caused by excessive retraction during operation in two cases. One patient expired due to cerebral hemorrhage occurring at previous cerebral infarction site. Conclusion: Carotid endarterectomy is a safe operative procedure showing low operative mortality. We suggest that intra-arterial shunt usage should be decided according to the ischemic change of electroercephalography regardless of the back pressure of internal carotid artery. Excessive retraction during operation should be avoided to prevent upper alway obstruction due to laryngeal edema and if upper airway obstruction is suspected, prompt management is essential.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.593-598
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• 1996

The large number of past investigation on extended myocardial protection clearly indicates that cold potassium cardioplegia and topical cooling have limited capabilities. Accordingly, more recent experimen- tal approaches have focused on the modalities of reperfusion and their implication on postischemic myo- cardial recovery. Oxygen may play a crucial role in the development of ischemic and reperfusion injury. Reactive oxygen radicals may be produced during ischemia or reperfusion after incomplete reduction of molecular oxygen or from other pathway and then induce fatal injury of the heart. The important obser- vation of oxygen-induced myocardial damage during reperfusion has led to the concept of applying oxy- gen free radical scavengers. So, this study is on dietary vitamin C supplementation as antioxidant in rats to determine whether or not they have a higher tolerance against cardiac ischemia-reperf'usion injury under Langendorff system. Male or female Sprague-Dawley rats (190-33Og) were randomly separated into two groups. Group A was not treated(n=10). Group B received vitamin C supplement (n=10). Experiment was performed 24 hours after vitamin C 200mg fed orally as injectable ascorbic acid. There were significant differences in contractile parameters between control and vitamin C-treated group. The RLVP (r te of post/preischemic left ventricular pressure) and Rdp/dt (rate of post/preischemic dp/dt) were significant statistically between two groups (p<0.05). But, RHR (rate of post/preischemic heart rate), time to first beat and sta'utilization were not significant. In conclusion, pretreatment with the antioxidant, ascorbic acid, was found to preserve left ventricular contractile function. But the precise mechanism of action of ascorbic acid has not as yet been determined, so further study will be required.

• The Korean Journal of Nuclear Medicine
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• v.32 no.2
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• pp.121-128
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• 1998

Purpose: $Na^+-K^+$ ATPase activity has been estimated by the degree of inhibition of cation transport by cardiac glycosides (ouabain) using Rb-86 as a substrate. The biological characteristisc of T1-201 is known to be similar to those of potassium as a transport substrate in the presence of glucose, insulin or phobol myristate acetate (PMA). The purpose of this study was to measure ouabain sensitive $Na^+-K^+$ ATPase activity using T1-201 and compare with that using Rb-86. Materials and Methods: Smooth muscle cells isolated from rat aorta or human placental umbilical artery were cultured, and used to measure cellular $Na^+-K^+$ ATPase activity. $Na^+-K^+$ ATPase activity was measured as a percentage decrease in cellular uptake of T1-201 or Rb-86 by ouabain under the presence of glucose, insulin or PMA in media. Results: $Na^+-K^+$ ATPase activity measured with T1-201, as a transport substrate, was not different from those measured with Rb-86 in rat or human smooth muscle cell preparation. Incubation with high concentration glucose resulted in about 30% decrease in enzyme activity. In contrast, insulin or PMA resulted in 10-70% or 28% increases from baseline activity, respectively. Conclusion: These results suggests that 71-201 could replace Rb-86 in measurement of ouabain sensitive $Na^+-K^+$ ATPase activity in vitro. High level of glucose concentration decreased cellular $Na^+-K^+$ ATPase activity, but insulin or PMA increased it.

• Journal of Chest Surgery
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• v.32 no.1
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• pp.1-4
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• 1999

Background: The transplantation of organs between phylogenetically disparate or harmonious species has invariably failed due to the occurrence of hyperacute rejection or accerelated acute rejection. But, concordant cardiac xenograft offer us an opportunity to study xenotransplantation in the absence of hyperacute rejection. Current therapeutics for the prolongation of survival of rodent concordant xenotransplantation are not ideal with many regimens having a high mortality rate. Cyclosporine A & Mycophenolate Mofetil are new immunosuppresive agent which has been shown to be effective at prolonging survival of allograft, as purine synthesis inhibitor. Material and Method: We used white mongrel rats as recipient and mice as donor, divided 4 groups(n=6), control group(Group 1) has no medication or pretreatment, Group 2 has splenectomy as pretreatment 7∼10 days before transplantation, Group 3 has Cyclosporine A treatment group, Group 4 has combined treatment of Cyclosporine A & Mycophenolate Mofetil(RS 61443). We compared survival time. Reuslt: We can't find significant difference of survival time between each groups. Conclusion: We concluded that rejection of cardiac xenograft was different from rejection of allograft, and new immunossuppresive Agent(Mycophenolate Mofetil, Cyclosporine A) was not effective for prolongation of survival time after cardiac xenograft.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.25-32
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• 2004

Purpose : Evaluate the efficacies and toxicities of concurrent chemoradiotherapy (CCRT), with or without intraluminal brachytherapy (ILB), using a retrospective analysis in esophageal carcinomas with respect to survival. Materials and Methods : From April 1995 to July 2001, a total of 65 patients, diagnosed with an esophageal carcinoma, were treated by CCRT, with 21 also treated by ILB after CCRT. External radiotherapy was peformed using 6 or 10 MV X-rays, with a dose range of $46.8~\69.6$ Gy (median; 59.4). The ILB was peformed using high-dose-rate brachytherapy with Ir-192. The fractionation of ILB was 3 Gy by 4, or 5 Gy by 2 fractions. Cisplatin $(75\;mg/m^2)$ was given on each first day of weeks 1, 5, 9 and 13, and 5-FU $(1,000\;mg/m^2)$ as a continuous infusion for the first 4 days of each course. Results : The median survival time of all patients was 15 months, and the 1, 2 and 3-year survival rates were 55.4, 29.2 and $20.7\%$, respectively. The 2-year survival rates of the patients with and without ILB were 33.3 and $27.3\%$, respectively (p=0.80). The 2-year survival rates of the patients with a complete, partial and no response were 44.1, 13.8 and $0\%$, respectively (p=0.02). The response to treatment was the only significant factor affecting the overall survival from a multivariate analysis. Conclusion : This study has shown that the survival outcomes of CCRT were much better than previous results with radiotherapy alone. However, the addition of ILB after CCRT showed no advantage over that of CCRT alone.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.42-51
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• 2001

Background : Recently, cardiopulmonary exercise testing (CPX) has become a popular diagnostic method for differentiating the main cause of exertional dyspnea or exercise limitation. We evaluated the difference in the CPX results according to interpretative algorithms and the methals of exercise in Korea. Method : Sixty-six patients with chronic lung disease and 48 adults with dyspneic symptoms, but with no abnormalities in a spirometry performed symptom limited CPX, were included in this study. The results were interpreted using both Wasserman's(WA) and Eschenbacher's algorithm (EA), and a comparison between both algorithms was made. Thirty-three healthy medical students performed the CPX with a cycle ergometer and treadmill. The results were interpreted with EA and the concurrence in interpretations was evaluated accord ing to the methods of exercise. Results : 1. In patients with chronic lung disease, the overall concordance rate between the two algorithms was 63.6%. The concordance rates waw 69.8% in patients with obstructive, 25.0% in those with restrictive, and 66.7% in those with mixed pulmonary insufficiency. In patients with dyspneic symptoms but normal findings in resting spirometry, the concordance rate was 60.4%. 2. In healthy medical students, in results inter preted with EA, the concordance rate between the cycle ergometer and treadmill exercise was 25.0%. Conclusion : Both interpretative algorithms and methods of exercise may affect the CPX results. In using CPX as a diagnostic test for the causes of dyspnea in the Korean population. the interpretative algorithms and method of exercise need to be standardized, and a predictive $VO_2$max equation needs to be established.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.837-844
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• 1998

Background: Adenosine is secreted by myocardial cells during myocardial ischemia or hypoxia. It has many beneficial effects on arrhythmias, myocardial ischemia, and reperfusion ischemia. Although many investigators have demonstrated that cardioplegia that includes adenosine shows protective effects in myocardial ischemia or reperfusion injury, reports of the optimal dose of adenosine in cardioplegic solutions vary. We reported the results of beneficial effects of single dosage(0.75 mg/Kg/min) adenosine by use of self-made Langendorff system. But it is uncertain that dosage was optimal. The objective of this study is to determine the optimal dose of adenosine in cardioplegic solutions. Material and Method: We used a self-made Langendorff system to evaluate the myocardial protective effect. Isolated rat hearts were subjected to 90 minutes of deep hypothermic arrest(15$^{\circ}C$) with modified St. Thomas' Hospital cardioplegia including adenosine. Myocardial adenosine levels were augmented during ischemia by providing exogenous adenosine in the cardioplegia. Three groups of hearts were studied: (1) group 1 (n=10) : adenosine - 0.5 mg/Kg/min, (2) group 2(n=10): adenosine -0.75 mg/Kg/min, (3) group 3 (n=10) : adenosine -1 mg/Kg/min. Result: Group 3 resulted in a significantly rapid arrest time of the heart beat(p<0.05) but significantly slow recovery time of the heart beat after reperfusion(p<0.05) compared to groups 1 and 2. Group 2 showed a better percentage of recovery(p<0.05) in systolic aortic pressure, aortic overflow volume, coronary flow volume, and cardiac output compared to groups 1 and 3. Group 1 showed a a better percentage of recovery(p<0.05) in the heart rate compared to the others. In biochemical study of drained reperfusates, CPK and lactic acid levels did not show significant differences in all of the groups. Conclusion: We concluded that group 2 [adenosine(0.75 mg/Kg/min) added to cardioplegia] has better recovery effects after reperfusion in myocardial ischemia and is the most appropriate dosage compared to group 1 and 3.

• Journal of Chest Surgery
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• v.34 no.6
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• pp.454-464
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• 2001

Background: It has been recognized that systemic inflammatory reaction and oxygen free radical formed by activated leukocyte in the procedure of cardiopulmonary bypass(CPB) frequently produce postoperative cardiac and pulmonary dysfunction. The purpose of this study was to evaluate the efficacy of leukocyte-depleting filters in the cardiopulmonary bypass circuit for patients undergoing open heart surgery(OHS). Material and method: The study involved 15 patients who underwent OHS with a Leukoguard-6 leukocyte filter placed in the arterial limbs of the bypass circuit(filter group, n=15) and 15 patients who did not have the filter(control group, n=15). We analyzed the differences between the groups in intraoperative changes of peripheral blood leukocyte and platelet counts, pre- and postbypass changes of malondialdehyde(MDA), troponin-T(TnT), 5'-nucleotidase(5'-NT) in coronary sinus blood, spontaneous recovery rate of heart beat after CPB, pre-and postoperative cardiac index(Cl) and pulmonary vascular resistance(PVR), and the amounts of postoperative bleeding and sternal wound complication. Result: During CPB, total leukocyte count of the filter group(9,567$\pm$ 842/㎣) was significantly less than that of the control group(13,573+1,167/㎣) (p<0.01), but there was no significant difference in platelet count between the groups. Postoperative levels of MDA(3.78+0.32 $\mu$mol/L vs 5.86+0.65 $\mu$mo1/L, p<0.01), TnT(0.40$\pm$0.04 ng/mL vs 0.59$\pm$0.08 ng/mL, p<0.05) and 5'-NT(3.88$\pm$0.61 U/L vs 5.80$\pm$0.90 U/L, p<0.05) were all significantly lower in the filter group than the control group. Postoperative Cl was higher in the filter group than the control group(3.26$\pm$0.18 L/$m^2$min vs 2.75$\pm$0.17 L/$m^2$/min, p=0.05). PVR of the filter group was lower than that of the control group(65.87$\pm$7.59 dyne/sec/cm$^{5}$ vs 110.80+12.22 dyne/sec/cm$^{5}$ , p<0.01). Spontaneous recovery rate of heart beat in the filter group was higher than that in the control group(12 patients vs 8 patients, p<0.05). Postoperative wound infection occurred in one case in the filter group and 4 case in the control group(p<0.05). Postoperative 24 hour blood loss of the filter group was more than that of the control group (614$\pm$107 mL vs 380+71 mL, p=0.05).