• 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.32 no.7
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• pp.628-636
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• 1999

Background: Recent advances in understanding the anatomy of the complete atrioventricular septal defect(including right-dominant unbalanced atrioventricular septal defect) have led to alternative methods of repairing these defects. Material and Method: From May 1997 to July 1998, 8 consecutive infants(age range, 2 to 28 months, mean body weight 6.0$\pm$2.2 kg) received a single-stage intracardiac repair of the complete atrioventricular septal defect with modified surgical methods. Depending on the specific anatomic structure, the procedure was simplified in 3 patients by a direct closure of the ventricular element of the defect(Group I). Two patients judged unsuitable for direct closure due to a potential left ventricular outflow tract obstruction had received a standard two-patch repair(Group II). The remaining 3 patients with right-dominant unbalanced complete atrioventricular septal defect underwent biventricular repair; to enlarge the orifice of the left atrioventricular valve, the ventricular septal patch was placed slightly more to the right of the ventricular crest, a left sided bridging leaflet was augmented with an autologous pericardial patch, and the leaflet was repaired with a double- orifice(Group III . Result: In all 8 patients, the postoperative echocardiography demonstrated good hemodynamics. Seven patients were weaned from the ventilators after a mean 3$\pm$1 days, and 1 patient was weaned after 24 days due to a reoperation and emphysematous lung problem. A reoperation was performed in 1 patient for progressive left atrioventricular valve regurgitation due to leaflet tearing. There were no early and late mortalities. At the time of the latest review, judging from the echocardiographic criteria, left atrioventricular valve stenosis was mild in 1 patient(mean pressure gradient 6.5 mmHg, 13.5%), left atrioventricular valve regurgitation was absent or grade I in 7 patients(87.5%). The right atrioventricular valve regurgitation was absent or grade I in all 8 patients(100%). Conclusion: Infants with complete atrioventricular septal defect were treated with either a simplified approach with direct closure of the ventricular element of the defect or a modified surgical technique for a right-dominant unbalanced atrioventricular septal defect, depending on the anatomic structure. The results were no operative mortalities and low morbidity.

• Journal of Chest Surgery
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• v.30 no.9
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• pp.869-875
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• 1997

Perimembranous ventri ular septal defects(PMVSDS) are the most common type of ventricular septal defects(VSDs) and consist morphologically of deficiency of the membranous septum and variable portions of the adjacent muscular septum. Repair of VSD has begun via a right ventriculotomy. Even with this exposure, however, it mght lead to ventricular dysfunction. Transatrial exposure of VSDs is luiown to a versatile approach to PMVSDS and even malaligunent defects can be repaired by this method. Although transatrial exposure can be improved by taking down'the atrioventricular valve at the annulus, surgeons have been hesitant to do so because of concern for valvular competence. Therefore, this study was undertaken to clarity the effects of transamlular approach of tricuspid valve (TATV) at operation of PMVSD. During last 5 years, twenty eight cases from 96 patients of PMVSD were closed by TATV and follow up study was done from 3 months to 33 months and results were obtained as follows. 1. Age at operation was fr m 4 months to 38 years and most patients(17, 62%) were above 5 years. 2. Preoperative pulmonary-systemic flow ratio(QPIQS) was ranged from 1 to 2.8 and 22 patients(79%) were less than 2. 3. Peak systolic pulmonary artery pressure was below 30mmHg in 8, 30-50mmHg in 17, above 50mmHg in 3 patients and 25 patients(89%) were less than 50mmHg. 4. Preoperative tricuspid regurgitation(TR) is none in 12, trivial in 6, mild in 3, moderate in 5, severe in 2 patients but postoperative TR was none in 18, trivial in 6, mild in 4 patients, so TR in most patients had decreased or not. 5. Indications for operation were based on the presence of a significant shunt. However, in patients with small shunts, indications for operation were included additional factors, tricuspid valve pouch, RVOT obstruction(right ventricular outflow tract obstruction), subacute bacterial endocarditis and associated anomalies. 6. There were no hospital deaths and residual shunts in postoperative echocardiography. Therefore TATV is especially a good method in PMVSn where patients have trcuspid valve pouch. And it is a safe and effective technique that improves exposure for PMVSD repair and does not adversely affect tricuspid valvular competence.

• The Journal of Internal Korean Medicine
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• v.21 no.4
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• pp.671-676
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• 2000

Pleural effusion is a state, retention of a mount of liquid in pleural cavity. Main causes of pleural effusion is Congestive Heart Failure that is caused by left ventricular heart failure. And that of Congestive heart failure is caused by increase of pleural capillary pressure or remain of effusion in pleural cavity. Bilateral venous pressure of pleura make worse pleural effusion and one way of venous pressure of that bring out pleural effusion. The purpose of this study is to examine the efficacy of oriental treatment for pleural effusion is caused by heart failure. One woman of 86 years old complained the symptom of general weakness, dyspnea, flank pain, anorexia, insomnia, coughing, secretion mixed blood. The symptom is caused by effusion that is brought out acute pneumonia, heart failure. At the time of Admission, in the diagnosis of Admission, in the diagnosis of Hyuneum(懸飮) she had taken Kungha-tang hap pleurisy-bang,(芎夏湯合助膜炎方), so improved dyspnea, flank pain, insomnia, coughing. In views of examination, decrease of heart failure' s symptom and pleural effusion. After 13days of admission, she had taken palmul-tang.(八物湯). As a conseguence of that, the symptom of general weakness. anorexia is improved and she was discharged.

• Journal of Sensor Science and Technology
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• v.9 no.1
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• pp.51-60
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• 2000

This paper outlines the development of a non-pulsatile axial flow type blood pump control system. By utilizing blood pressure and heart rate, this system can assist the left ventricle in controlling blood pressure and blood volume. The system is comprised of a blood pump, signal sensor, signal interface, and signal-processing component. A control algorithm is also proposed which can control non-pulsatile, continuous blood flow in the human circulatory system. To facilitate the control required for non-pulsatile blood pump in a physiological system, an experimental control rule was developed utilizing ECG and blood pressure data, both of which are easily detectable variables in the body. The system was then tested using a mock-up circulation system and we found that it is possible that this systems could be temporarily used in clinic.

• Journal of Chest Surgery
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• v.31 no.6
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• pp.567-575
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• 1998

Panax Ginseng C.A. Meyer has been known for hundreds of years as the most valuable drug having mysterious effects among all the herbal medicines and plants in Korea. Also, many experimental studies have been performed recently that the various effects were identified and applied clinically. So we attempted an experimental study on the effect of ginsenoside Rg1 mixtures in an isolated rat heart with the use of the Langendorff model. The objective of this study was to determine whether this ginsenoside Rg1 mixtures would protect the myocardial injury after ischemic arrest and reperfusion. Isolated rat hearts were allowed to equilibrate for 20 minutes and were then subjected to 15 minutes of normothermic ischemia. After this ischemic period, isolated rat hearts were allowed to reperfusion for 10 minutes(Ischemic Group). In other group , isolated rat hearts were perfused for 60 minutes continuously with normothermia( Normothermic Group). Hemodynamic and biochemical parameters such as heart rate, left ventricular pressure, +dp/dt max, coronary blood flow and cardiac enzymes were measured during initial perfusion, ischemia, reperfusion period (Ischemic group) and 20, 40 and 60 minutes after continuous perfusion(Normothermic group). After completion of the experiment, this data was evaluated and the following results were obtained. 1. Heart rates showed an increase in both ischemic and normothermic experimental groups, but statistically significant differences were not identified. 2. LVP(Left Ventricular Pressure) showed statistically significant differences in both ischemic and normothermic experimental groups(p<0.005, p<0.01). 3. +dp/dt max showed statistically significant differences in both ischemic and normothermic experimental groups(p<0.01, p<0.01). 4. There were no statistically significant differences in coronary blood flow and cardiac cenzymes in all groups, but experimental groups seemed to have better protection and recovery. These results suggest that ginsenoside Rg1 mixtures has a protective effect on the myocardial injury after ischemia and reperfusion.

• Journal of Chest Surgery
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• v.15 no.1
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• pp.90-97
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• 1982

Two hundred one patients of ventricular septal defect, which were operated at Seoul National University Hospital, were analysed on clinical background during the period from January, 1975 to December, 1980. The results were as follows: 1. Of the 201 patients, 118 patients were male [58.7%] and 83 patients were female [41.3%]. Their age ranged from 15 months to 40 years, and the mean age was 8.7 years. 40% of the patients were between 4 and 8 years. 2. The most common symptoms showed frequent U RI and exertional dyspnea. 3. On Kirklin`s anatomical classification, type I constituted 26.9%, type II 58.2%, type III 12.4%, and type IV 1.0%. We showed marked increased incidence of type I VSD as compared to Caucasians* 4. 46 cases were associated with other congenital cardiac diseases. They were PDA [13 cases], AI[11 ], ASD[6], PS[10], MI[4], and Double aortic arch [1]. 5. In 128 patients, who had complete hemodynamic data and were not associated with other congenital cardiac diseases, an attempt was made to correlate the EKG findings with the hemodynamic data, and defect size with the hemodynamic data. The children had variable distribution of PA syst. pr. and Rp/Rs. But most of adults had $R_P$/$R_S$of 0.15 or less. As $P_P$/$P_S$increased, the rate of operative complication increased also. 6. When a normal EKG pattern was present, $Q_P$/$Q_S$and $R_P$/$R_S$and $P_P$/$P_S$were relatively low. When EKG findings were LVH pattern, there was diastolic volume overload to left ventricle. As RVH, there was systolic pressure overload to right ventricle. And as BVH, there was mixed pattern of diastolic volume overload to left ventricle and systolic pressure overload to right ventricle. 7. Among patients in defect was less than 1 $cm^2$ per $M^2$ of BSA, $Q_P$/$Q_S$was less than 2:1, and $R_P$/$R_S$less than 0.25, and PAsyst. pr. less than 50 mmHg, and $P_P$/$P_S$was less than 0.5. But patients with the defect greater than 1 $cm^2$ per $M^2$ of BSA had no correlationship between $Q_P$/$Q_S$, $R_P$/$R_S$, PAsyst. pr. and defect size in each other. Most of patients with the defect greater than 2 $cm^2$/$M^2$ BSA, $R_P$/$R_S$was greater than 0.5. 8. Operative mortality rate was 9.5% [19 cases] among 201 patients. And complication rate including mortality rate was 22.9% [46 cases].

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.205-214
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• 2006

Background : Acute exacerbations form a major component of the socioeconomic burden of COPD. As yet, little information is available about the long-term outcome of patients who have been hospitalized with acute exacerbations, although high mortality rates have been reported. The aim of this study was to determine predictors of long-term mortality after hospitalization for acute exacerbation of COPD. Methods : We performed a retrospective cohort study of consecutive patients admitted to the hospital for COPD exacerbation between 2000 through 2004. Patients who had died in hospital or within 6-months after discharge, had tuberculosis scar, pleural thickening or bronchiectasis by chest radiography or had been diagnosed with malignancy during follow-up periods were excluded. Results : Mean age of patients was 69.5 years, mean follow-up duration was 49 months, and mean $FEV_1$ was 1.00L (46% of predicted). Mortality was 35% (17/48). In the multivariate Cox regression analysis, heart rate of 100/min or more (p=0.003; relative risk [RR], 11.99; 95% confidence interval [CI], 2.34-61.44) and right ventricular systolic pressure (RVSP) of 35mmHg or more (p=0.019; RR, 6.85; 95% CI, 1.38-34.02) were independent predictors of mortality. Conclusion : Heart rate and RVSP in stable state may be useful in predicting long-term mortality for COPD patients admitted to hospital with acute exacerbation.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.569-576
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• 2007

Ventricular Assist Device(VAD) has switched its goal from a short-tenn use for bridge-to-transplantation to a long-tenn use for destination therapy, With this goal, the importance of long-tenn reliability gets more interests and importances, H-VAD is an portable extracorporeal biventricular assist device, and adopts an electro-pneumatic driving mechanism. The pneumatic pressure to pump out blood is generated with compression of bellows, and is transmitted in a closed pneumatic circuit through a pneumatic line. The existing pneumatic VAD adopts a air compressor which can generate stable pressures but has defects such as a noise and a size problem. Thus, it is not suitable for being used as a portable device, These problems are covered with adopting a closed pneumatic circuit mechanism with a bellows which has a small size and small noise generation, but it has defects that improper pneumatic setting causes a failure of adequate flow generation. In this study, the pneumatic pressure regulation system is developed to cover these defects of a bellows-type pneumatic VAD. The optimal pneumatic pressure conditions according to various afterload conditions for an optimal flow rate were investigated and the afterload estimation algorithm was developed, The final pneumatic regulation system estimates a current afterload and regulate the pneumatic pressure to the optimal point at a given afterload condition. The afterload estimation algorithm showed a sufficient performance that the standard deviation of error is 8.8 mmHg, The pneumatic pressure regulation system showed a sufficient performance that the flow rate was stably governed to various afterload conditions. In a further study, if a additional sensor such as ultrasonic sensor is developed to monitor the direct movement of diaphragm in a blood pump part, the reliability would be greatly increased. Moreover, if the afterload estimation algorithm gets more accuracy, it would be also helpful to monitor the hemodynamic condition of patients.

• The Korean Journal of Nuclear Medicine
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• v.35 no.3
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• pp.152-160
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• 2001

Purpose: We tried to establish the reproducibility of the measurement of maximal elastance (Emax) and to compare the degree of the reproducibility of two estimation methods: single pressure-volume loop method and parameter optimization method. Materials and methods: In 47 patients (42 males and 5 females, $53{\pm}10$ years old) with suspected coronary artery disease (election fraction; 22-68%), gated Tc-99m MIBI myocardial SPECT and arterial tonometry were acquired. In 11 patients among these 47 patients, gated SPECT and tonometry were performed twice consecutively with patients in situ. Emax and void volume (Vo) were estimated using single pressure-volume loop method of Lee and parameter optimization method based on linear approximation of Yoshizawa. Correlation between the consecutive measurements by each method and correlation between the two estimation methods were compared. Results: Reproducibility of Emax (r=0.96) and Vo (r=0.99) by single pressure-volume method was better than the reproducibility of Emax (r=0.89) and Vo (r=0.64) by parameter optimization method. Correlations of Emax and Vo were fair between the two methods. The correlation of Emax (r=0.77) was better than that of Vo (r=0.55). Conclusion: Reproducibility of Emax measurement by single pressure-volume loop method using gated myocardial SPECT and arterial tonometry was excellent. Reproducibility by parameter optimization method was also fair but was less than that achieved by single pressure-volume method.