• Clinical and Experimental Pediatrics
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• v.61 no.12
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• pp.392-396
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• 2018

Purpose: Adenotonsillar hypertrophy (ATH) that causes upper airway obstruction might lead to chronic hypoxemic pulmonary vasoconstriction and right ventricular (RV) dysfunction. We aimed to evaluate whether adenotonsillectomy (T&A) in children suffering from obstructive sleep apnea (OSA) due to severe ATH could improve RV function. Methods: Thirty-seven children (boy:girl=21:16; mean age, $9.52{\pm}2.20years$), who underwent T&A forsleep apnea due to ATH, were included. We analyzedthe mean pulmonary artery pressure (mPAP), the presence and the maximal velocity of tricuspid regurgitation (TR), the tricuspid annular plane systolic excursion (TAPSE), and the right ventricular myocardial performance index (RVMPI) with tissue Doppler echocardiography (TDE) by transthoracic echocardiography pre- and post-T&A. The follow-up period was $1.78{\pm}0.27years$. Results: Only the RVMPI using TDE improved after T&A ($42.18{\pm}2.03$ vs. $40{\pm}1.86$, P=0.001). The absolute value of TAPSE increased ($21.45{\pm}0.90mm$ vs. $22.30{\pm}1.10mm$, P=0.001) but there was no change in the z score of TAPSE pre- and post-T&A ($1.19{\pm}0.34$ vs. $1.24{\pm}0.30$, P=0.194). The mPAP was within normal range in children with ATH, and there was no significant difference between pre- and post-T&A ($19.6{\pm}3.40$ vs. $18.7{\pm}2.68$, P=0.052). There was no difference in the presence and the maximal velocity of TR (P=0.058). Conclusion: RVMPI using TDE could be an early parameter of RV function in children with OSA due to ATH.

• Tuberculosis and Respiratory Diseases
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• v.46 no.6
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• pp.846-855
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• 1999

Background : Secondary pulmonary hypertension is an important final endpoint in patients with chronic hypoxic lung disease, accompanied by deterioration of pulmonary hemodynamics. The clinical diagnosis of pulmonary hypertension and/or cor pulmonale could be difficult, and simple noninvasive evaluation of pulmonary artery pressures has been an relevant clinical challenge for many years. Doppler echocardiography might to be a more reliable method for evaluating pulmonary hemodynamics in such patients in terms of the accuracy, reproducibility and easiness for obtaining an appropriate echocardiographic window than M-mode echocardiography. The aim of this study was to assess echocardiographic parameters associated with pulmonary arterial hypertension, defined by increasing right ventricular systolic pressure(RVSP), calculated from trans-tricuspid gradient in patients with chronic hypoxic lungs. Method : We examined 19 patients with chronic hypoxic lung disease, suspected pulmonary hypertension under the clinical guidelines by two dimensional echocardiography via the left parasternal and subcostal approach in a supine position. Doppler echocardiography measured RVSP from tricuspid regurgitant velocity in continuous wave with 2.5MHz transducer and acceleration time(AT) on right ventricular outflow tract in pulsed wave for the estimation of pulmonary arterial pressure. Results : On echocardiography, moderate to severe degree of pulmonary arterial hypertension was defined as RVSP more than 40mmHg, presenting tricuspid regurgitation. Increased right ventricular endsystolic diameter and shortened AT were noted in the increased RVSP group. Increased RVSP was correlated negatively with the shortening of AT. Other clinical data, including pulmonary functional parameters, arterial blood gas analysis and M mode echocardiographic parameters were not changed significantly with the increased RVSP. Conclusion : These findings suggest that shortened AT on pulsed doppler can be useful when quantifying pulmonary arterial pressure with increased RVSP in patients with chronic lung disease with hypoxemia. Doppler echocardiography in pulmonary hypertension of chronic hypoxic lungs is an useful option, based on noninvasiveness under routine clinical practice.

• Journal of Chest Surgery
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• v.24 no.2
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• pp.123-134
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• 1991

Twenty eight patients had undergone repair of an isolated complete atrioventricular septal defect between April 1986 and September 1990 in Seoul National University Children`s Hospital. The group comprised 13 male and 15 female patients. They ranged in age from 2 months to 8 years[mean 18.6months] and in weight from 3. 4kg to 23kg[mean 9.0$\pm$4.6kg]. They were analysed as Rastelli type A in 17 patients, Rastelli type B in 2 patients, and Rastelli type C in 9 patients. Seven patients had concomitant Down`s syndrome. All patients had large left-to-right shunt[mean pulmonary to systemic flow ratio 3.5 $\pm$2.2 ranging from 0.68 to 10.0] and high pulmonary systolic pressure[mean 74$\pm$18.8mmHg, ranging from 35 to 110]. In 11 patients, one patch technique was used to close the atrial and ventricular septal defect and 16 patients were undergone by two patch technique. We urgently managed only one patient by pulmonary artery banding whose anatomy was Rastelli type C and severe mitral regurgitation was identified. Postoperative complete A - V block was noted in 3 patients, two of whom were dead in operating room due to combined LVOTO and myocardial failure, and one patient with Rastelli type C was undergone by VVI type permanent pacemaker insertion 1wk later after two patch technique, but we had to manage him by modified Konno operation and total correction due to LVOTO and VSD leakage and severe mitral regurgitation 3 years later. Another two reoperation cases due to severe mitral regurgitation after two patch technique were undergone, one of whom we managed by mitral annuloplasty 3 months later but aggravated mitral regurgitation made us to control him by MVR 3 months later. Another one case of VSD leakage and tricuspid regurgitation was managed by total correction but she died of respiratory insufficiency 14 days later. We experienced pulmonary hypertensive crisis in 3 patients, who were dead in two cases comparing with one control case. So operative mortality is 9/27[33.6%], in one patch group of 3/11[29.2%] comparing with two patch group of 6/16[37.5%]. In summary, causes of death were pump weaning failure, myocardial failure and low cardiac output syndrome and pulmonary hypertensive crisis, resp. failure, complete AV block. Mean follow up period is 15.8$\pm$10.7 months[ranging from 3months to 37 months]

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.195-202
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• 2010

Purpose : Despite recent advances in pulmonary hypertension management and surgery, appropriate guidelines remain to be developed for operability in congenital heart disease with pulmonary artery hypertension (PAH). Our aim was to evaluate clinical outcomes of patients with severe PAH who underwent surgical closure of left-to-right shunt lesions (LRSL) on the basis of pulmonary reactivity. Methods : We retrospectively reviewed 21 patients who underwent surgical closure of LRSL with severe PAH (${\geq}8$ Wood unit) from January 1995 to April 2009. The median age at operation was 26 years. Atrial septal defect, ventricular septal defect (VSD), VSD and patent ductus arteriosus (PDA), and PDA was present in 11, 4, 4, and 2 patients, respectively. Results : Operability was based on vasoreactivity of PAH. Of the 21 patients, 5 showed response to pulmonary vasodilator therapy and 8 showed vasoreactivity after balloon occlusion of defects. The remaining 8 patients were considered operable because of significant left-to-right shunt (Qp/Qs ${\geq}1.5$). Five patients underwent total closure of defects and 16 were left with small residual shunts. The median follow-up duration was 32 months. There was no significant postoperative mortality or morbidity. Systolic pulmonary artery pressure (PAP) decreased in all but 2 patients. All patients except 1 showed improvement of New York Heart Association functional class. Conclusion : Closure of LRSL in patients with severe PAH on the basis of pulmonary vasoreactivity seems reasonable. PAP and clinical symptoms improved in most patients. Further research is needed for the evaluation of long-term results.

• Journal of Chest Surgery
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• v.36 no.8
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• pp.576-582
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• 2003

During the Off-Pump Coronary Arterial Bypass surgery (OPCAB), the manipulation of the heart can depress cardiac contractility and cause hemodynamic instability. In this study, hemodynamic parameters were measured during operation and the laboratory and clinical data were investigated to evaluate their effects on postoperative outcome. Material and Method: From March 2001 to August 2002, 50 consecutive patients who underwent OPCAB were included in this study. During the same period, total number of CABG was 71 The blood pressure, pulmonary artery pressure, mixed venous oxygen saturation, and cardiac index were measured before manipulation, after application of stabilizer, and at the end of anastomosis. Postoperatively, we measured the cardiac enzymes such as CK-MB, troponin 1 and checked the amount of inotropes required, chest tube drainage, the amount of transfusion, duration of ventilator support, and duration of ICU stay. Result: The number of mean distal anastomoses was 2.8$\pm$0.9 per patient. On elevation and stabilization of the heart, systolic blood pressure was depressed and pulmonary artery pressure was elevated significantly, but during each anastomosis no significant changes were detected. The peak level of cardiac markers was 29.2$\pm$46.7 for CK-MB, 0.69$\pm$0.86 for troponin 1 on postoperative day f. Among the intraoperative hemodynamic parameters, the ischemic change of EKG and bolus injection of inotropes significantly affected the posteroperative cardiac enzymes. But, no difference other than the level of cardiac enzymes between the two groups with or without the ischemic change of EKG and bolus injection of inotropes was noticed. Conclusion: The significant hemodynamic changes occurred when the heart was elevated and stabilized, however during anastomoses there were no significant changes. Serum cardiac enzymes rose significantly in the group that showed the ischemic charge of EKG or needed the bolus injection of inotropes for maintaining hemodynamic stability intraoperatively, but it did not affect the postoperative outcome. In conclusion, the ischemic change of EKG and the need for bolus injection of intropes during operation may be very indicative for probable ischemia.

• Journal of Chest Surgery
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• v.43 no.3
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• pp.254-259
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• 2010

Background: Diagnosing chronic pulmonary embolism at an early stage is difficult because of the patient’s nonspecific symptoms. This condition is not prevalent in Korea, and in fact, there have been only a few case reports on this in the Korean medical literature. We analyzed the surgical outcome of performing pulmonary thromboendarterectomy in patients with chronic pulmonary embolism. Material and Method: The study subjects included those patients who underwent surgery for chronic pulmonary embolism from 1996 to 2008. For making the diagnosis, echocardiography, chest CT and a pulmonary perfusion scan were performed on the patients who complained of chronic dyspnea. Result: Pulmonary endarterectomy was performed as follows: by incision via a mid-sternal approach (7 patients); by incision via a left posterolateral approach (1 patient); using the deep hypothermic circulatory arrest technique (4 patients); under ventricular fibrillation (3 patients); and under cardioplegic arrest (1 patient). The postoperative systolic pulmonary artery blood pressure significantly decreased from a preoperative value of $78.9{\pm}14.5\;mmHg$ to $45.6{\pm}17.6\;mmHg$ postoperatively (p=0.000). The degree of tricuspid regurgitation was less than grade II after surgery. Two patients died early on, including one patient who had persistent pulmonary hypertension without improvement and right heart failure. Conclusion: Patients who have chronic pulmonary embolism are known to have a poor prognosis. However, we think that early surgical treatment along with making the proper diagnosis before the aggravation of right heart failure can help improve the quality of a patient's life.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.321-326
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• 1992

The study consisted of all patients over 35years old undergoing surgical repair of atrial septal defect for the period from June 1985, to August 1992. The following results were observed. 1. ASD was closed with patch in 11(73%) patients. 2. The relationship of pulmonary artery systolic pressure to Qp/Qs ratio was not significant. 3. Before operation 6 patients were in NYHA functional class II, 8 were in class III, After operation 8 patients were in class I, 6 were in class II. 4. Atrial fibrillation has persisted in 3 patients and returned regular rhythm in 1 patient after surgery. 5. There was no operative mortality and we had good surgical results regardless of patient's age.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.103-120
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• 1967

As pointed out by many previous investigators, the cardio-pulmonary system of well trained athletes is so adapted that they can perform a given physical exercise more efficiently as compared to non-trained persons. However, the time course of the development of these cardio-pulmonary adaptations has not been extensively studied in the past. Although the development of these training effects is undoubtedly related to the magnitude of an exercise load which is repeatedly given, it would be practical if one could maintain a good physical fitness with a minimal daily exercise. Hence, the present investigation was undertaken to study the time course of the development of cardio-pulmonary adaptations while a group of non-athletes was subjected to a daily 6 to 10 minutes running exercise for a period of 4 weeks. Six healthy male medical students (22 to 24 years old) were randomly selected as experimental subjects, and were equally divided into two groups (A and B). Both groups were subjected to the same daily running exercise (approximately 1,000 kg-m). 6 days a week for 4 weeks, but the rate of exercise was such that the group A ran on treadmill with 8.6% grade for 10 min daily at a speed of 127 m/min while the group B ran for 6 min at a speed of 200 m/min. In order to assess the effects of these physical trainings on the cardio-pulmonary system, the minute volume, the $O_2$ consumption, the $CO_2$ output and the heart rate were determined weekly while the subject was engaged in a given running exercise on treadmill (8.6% grade and 127 m/min) for a period of 5 min. In addition, the arterial blood pressure, the cardiac output, the acid-base state of arterial blood and the gas composition of arterial blood were also determined every other week in 4 subjects (2 from each group) while they were engaged in exercise on a bicycle ergometer at a rate of approximately 900 kg m/min until exhaustion. The maximal work capacity was also determined by asking the subject to engage in exercise on treadmill and ergometer until exhaustion. For the measurement of minute volume, the expired gas was collected in a Douglas bag. The $O_2$ consumption and the $CO_2$ output were subsequently computed by analysing the expired gas with a Scholander micro gas analyzer. The heart rate was calculated from the R-R interval of ECG tracings recorded by an Offner RS Dynograph. A 19 gauge Cournand needle was inserted into a brachial artery, through which arterial blood samples were taken. A Statham $P_{23}AA$ pressure transducer and a PR-7 Research Recorder were used for recording instantaneous arterial pressure. The cardiac output was measured by indicator (Cardiogreen) dilution method. The results may be summarized as follows: (1) The maximal running time on treadmill increased linearly during the 4 week training period at the end of which it increased by 2.8 to 4.6 times. In general, an increase in the maximal running time was greater when the speed was fixed at a level at which the subject was trained. The mammal exercise time on bicycle ergometer also increased linearly during the training period. (2) In carrying out a given running exercise on treadmill (8.6%grade, 127 m/min), the following changes in cardio·pulmonary functions were observed during the training period: (a) The minute volume as well as the $O_2$ consumption during steady state exercise tended to decrease progressively and showed significant reductions after 3 weeks of training. (b) The $CO_2$ production during steady state exercise showed a significant reduction within 1 week of training. (c) The heart rate during steady state exercise tended to decrease progressively and showed a significant reduction after 2 weeks of training. The reduction of heart rate following a given exercise tended to become faster by training and showed a significant change after 3 weeks. Although the resting heart rate also tended to decrease by training, no significant change was observed. (3) In rallying out a given exercise (900 kg-m/min) on a bicycle ergometer, the following change in cardio-vascular functions were observed during the training period: (3) The systolic blood pressure during steady state exercise was not affected while the diastolic blood Pressure was significantly lowered after 4 weeks of training. The resting diastolic pressure was also significantly lowered by the end of 4 weeks. (b) The cardiac output and the stroke volume during steady state exercise increased maximally within 2 weeks of training. However, the resting cardiac output was not altered while the resting stroke volume tended to increase somewhat by training. (c) The total peripheral resistance during steady state exercise was greatly lowered within 2 weeks of training. The mean circulation time during exorcise was also considerably shortened while the left heart work output during exercise increased significantly within 2 weeks. However, these functions_at rest were not altered by training. (d) Although both pH, $P_{co2}\;and\;(HCO_3-)$ of arterial plasma decreased during exercise, the magnitude of reductions became less by training. On the other hand, the $O_2$ content of arterial blood decreased during exercise before training while it tended to increase slightly after training. There was no significant alteration in these values at rest. These results indicate that cardio-pulmonary adaptations to physical training can be acquired by subjecting non-athletes to brief daily exercise routine for certain period of time. Although the time of appearance of various adaptive phenomena is not identical, it may be stated that one has to engage in daily exercise routine for at least 2 weeks for the development of significant adaptive changes.

• Journal of Chest Surgery
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• v.40 no.3 s.272
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• pp.193-199
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• 2007

Background: Reoperation is usually required for a right ventricle to pulmonary artery conduit obstruction caused by valve degeneration, conduit peel formation or somatic growth of the patient. An autologous tissue reconstruction (peel operation), where a prosthetic roof is placed over the fibrotic tissue bed of the explanted conduit, has been used to manage conduit obstructions at our institute since May 2002. Herein, the early and midterm results are evaluated. Material and Method: Between May 2002 and July 2006, 9 patients underwent obstructed extracardiac conduit replacement with an autologous tissue reconstruction, at a mean of 5.1 years after a Rastelli operation. The mean age at reoperation was $7.5{\pm}2.4$ years, ranging from 2.9 to 10.1 years. The diagnoses included 6 pulmonary atresia with VSD, 2 truncus arteriosus and 1 transposition of the great arteries. The preoperative mean systolic gradient was $88.3{\pm}22.2mmHg$, ranging from 58 to 125 mmHg. The explanted conduits were all Polystan valved pulmonary conduit (Polystan, Denmark). A bioprosthetic valve was inserted in 8 patients, and a monocusp ventricular outflow patch (MVOP) was used in 1 patient. The anterior wall was constructed with a Gore-Tex patch (n=7), MVOP (n=1) and bovine pericardium (n=1). Pulmonary artery angioplasty was required in 5 patients and anterior aortopexy in 2. The mean cardiopulmonary bypass time . was 154 minutes, ranging from 133 to 181 minutes; an aortic crossclamp was not performed in all patients. The mean follow-up duration was 20 months, ranging from 1 to 51 months. All patients were evaluated for their right ventricular outflow pathway using a 3-D CT scan. Resuit: There was no operative mortality or late death. The mean pressure gradient, assessed by echocardiography through the right ventricular outflow tract, was 20.4 mmHg, ranging from 0 to 29.6 mmMg, at discharge and 26 mmHg, ranging from 13 to 36 mmHg, at the latest follow-up (n=7, follow-up duration >1 year). There were no pseudoaneurysms, strictures or thrombotic occlusions. Conclusion: A peel operation was concluded to be a safe and effective re-operative option for an obstructed extracardiac conduit following a Rastelli operation.

• Clinical and Experimental Pediatrics
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• v.52 no.4
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• pp.494-498
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• 2009

Purpose : Applicability of transcatheter closure of atrial septal defect (ASD) has been expanded by accumulation of clinical experiences and evolutions of the device. This study was performed to evaluate the safety and efficacy of transcatheter closure of ASD with Amplatzer septal occluder (ASO) in young children less than 3 years of age. Methods : From May 2003 to December 2005, 295 patients underwent transcatheter closure of ASD with ASO in the Severance Cardiovascular Hospital, Yonsei University Health System. Among them, 51 patients less than 3 years of age were enrolled in this study. We investigated procedural success rate, rate of residual shunt, frequency of complications, procedure/fluoroscopy time, and need of modified techniques for device implantation. Results : The median age was 2.1 years and median body weight was 12 kg. Implantation of device was successful in 50 patients (98%). Seven patients (15%) showed a small residual shunt 1 day after the procedure, but complete occlusion had been documented at 6 month follow-up in all patients (100%). The pulmonary to systemic flow ratio (Qp/Qs), peak systolic pulmonary artery pressure, and peak systolic right ventricular pressure had decreased significantly after closure of ASD. There were 2 complications including device embolization (1, 2%) and temporary groin hematoma (1, 2%). Conclusion : Transcatheter closure of ASD with ASO can be performed with satisfactory results and acceptable risk even in young children less than 3 years of age. We could suggest that even in very young children with ASD, there is no need to wait until they grow to a sufficient size for the transcatheter closure.