• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.3
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• pp.378-382
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• 2006

This paper presents an approach to detect premature ventricular contractions(PVC) using the neural network with weighted fuzzy membership functions(NEWFM). NEWFM classifies normal and PVC beats by the trained weighted fuzzy membership functions using wavelet transformed coefficients extracted from the MIT-BIH PVC database. The two most important coefficients are selected by the non-overlap area distribution measurement method to minimize the classification rules that show PVC classification rate of 99.90%. By Presenting locations of the extracted two coefficients based on the R wave location, it is shown that PVC can be detected using only information of the two portions.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.643-649
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• 2017

심장 이온통로의 변화는 활동전압의 모양과 길이에 영향을 주어 심부정맥을 유발한다. 산화적 스트레스의 증가로 인해 생체에 침착이 증가하는 지질산화물 (4-HNE, 4-ONE)는 여러 단백질 및 이온통로에 영향을 주는 독성이차전달자로 알려져 있다. 본 연구자는 선행 연구를 통해 4-HNE와 4-ONE의 단기간 노출이 심실근세포에 발현되는 3종류의 이온통로 ($I_{Kr}$, $I_{Ks}$, $I_{Ca,L}$)의 전류감소와 kinetics변화를 일으키고, 심실근세포의 활동전압길이가 증가하는 것을 확인하였다. 두 물질이 이온통로들에 준 영향은 유사하였으나, 활동전압길이의 증가 정도가 4-ONE에서 더 크게 나타났다. 활동전압의 연장에 차이가 나는 원인과, 두 지질산화물이 또 다른 이온통로에 미치는 영향 유무를 예측하기 위해서 Grandi and Bers human ventricular model[1]을 적용한 Integrated human ventricular myocyte model 프로그램 (developed by prof. Youm)을 활용하였다. 시뮬레이션으로 재현한 4-HNE와 4-ONE에 의한 활동전압은 실험으로 기록된 것보다 연장 정도가 작았다. 시뮬레이션 모델의 background $Na^+$ 전류의 크기를 크게 하였을 경우, 실험에서 기록된 활동전압 길이에 상응하는 연장을 가져왔다. 그러므로, 4-HNE와 4-ONE는 실험으로 확인한 $I_{Kr}$, $I_{Ks}$, $I_{Ca,L}$ 이외에 심장세포에 존재하는 내향전류 (Late $Na^+$ current)의 크기를 증가하는 효과가 있음을 예측할 수 있으며, 실험적 검증이 요구된다.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.656-661
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• 2017

이 연구의 목적은 심근경색의 발생 위치와 그 부피에 따른 심실의 여러 가지 생리학적인 특성들을 분석하는 데에 있다. 우리는 심근경색의 발생 사례를 총 8가지로 분류하여 각 병변의 발생 위치와 부피를 달리 하였으며 대조군으로 정상 상태의 심장을 두어 기준 값으로부터 각 사례 별로 전체 심장 대비 심근경색 부위가 차지하는 비율, 압력-부피 선도, 1회 박출량(SV), 분당 심박출량(CO), ATP 소모율, 박출 효율(EF), 1주기의 1ATP 당 소모한 일의 양(SW/ATP) 등을 조사하였다. 또한 본 연구는 심근경색의 발생 위치와 부피에 따른 이의 심각성을 나타내고자 했기 때문에, 각 사례 별로 압력-부피 선도, 들의 변화율 및 세포가 괴사한 정도에 따른 수치 변화율을 퍼센트(%)로 표시하여 그 정도를 조사하였다. 심근경색을 가진 심장은 그렇지 않은 심장에 비해서, ATP 소모량이나 EF의 경우 각 사례 마다 상이한 결과를 가지기는 하지만, 대체적으로 더 적은 1주기 일량(SW) 및 1회 박출량(SV) 분포를 보였으며 SW/ATP의 값은 거의 일괄적으로 감소하였음을 확인하였는데, 이는 심실의 효율이 정상 심장에 비해서 떨어졌음을 의미한다. 결과적으로, 본 연구는 심근경색의 생리학적 특징들을 재확인함과 동시에 임상적으로 확인할 수 없는 특징들의 수학적인 분석과 더불어 심근경색의 공간 특징적인 현상들을 밝히고 있다.

• Journal of Chest Surgery
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• v.29 no.11
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• pp.1207-1211
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• 1996

During the recent 10 years, ten patients with ruptured sinus of Valsalva were operated on our institute. Eight patients were congenital but two patients were proved acquired lesions due to bacterial endocarditis. Coexistent cardiac lesions were 4 aortic regurgitations, 2 atrial septal defects, 1 ventricular septal defect, 1 tricuspid regurgitation and 1 mitral regurgitation. In all cases, aneurysms of sinus of Valsalva arose from the right coronary sinus, and they ruptured to right ventricle in 8 patients and to right atrium in 2 patients. We preferred double approach, through both the aorta and the involver. cardiac chamber, The repair of ruptured site was performed Dacron patch graft in 8 patients and simple closure in 2 patients. Operative results were very good in all cases with no surgical mortality.

• Journal of Chest Surgery
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• v.29 no.9
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• pp.945-950
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• 1996

Twelve patients with left ventricular-right atrial shunt (LV-RA shunt) underwent surgical correction be- tween April 1982 and March 1995. Seven patients were male and five patients were female. Age ranged from 3 to 26 years with mean age of 8.5 years. On the preoperative chest PA views, increased pulmonary vascularity was noted in 3 cases and enlargement of right atrium in 4 cases. The mean preoperative cardiothoracic ratio was 0.59. Echocardiographic studies were obtained in 9 patients and the preoperative echocardiographic diagnoses were LV-RA shunt in 2 cases, ventricular septal defect (VSD) in 6 casei, and atrial septal defect (ASD) in 1 case. The preoperative ngiographic diagnoses which were obtained in all patients were LV-RA shunt in 5 cases, VSD in 5 cases, ASD in 1 case, and VSD with ASD in 1 case. The descriptions of defect of LV-RA shunt according to intraoperative findings were supravalvular defect in 5 cases(42%), infravalvular defect in 4 cases (33%), and combined defect in 3 cases (25%). Associated anomalies of tricuspid valve in 4 cases of infravalvular defect were perforation (3 cases) and cleft (1 case). Primary closure of the septal defect was performed through the right atriotomy in all but one patient. There was no operative death. One patient underwent reoperation because of the residual interventricular shunt. All patients have been in good condition.

• The Korean Journal of Malacology
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• v.31 no.4
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• pp.291-298
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• 2015

This study was conducted to provide the microanatomical information of the heart-kidney complex of Tegillarca granosa. The heart-kidney complex was located in the pericardial cavity between the dosal visceral mass and posterior adductor muscle. The heart composed of two atrium and one ventricle. The kidney composed of a pair of left and right. The atrium and ventricle of the heart were composed of the epicardium, myocardium and endocardium. The epicardium of simple epithelial layer composed of cuboidal epithelial cells that had a strong basophilic nucleus located in the center. The myocardium composed of muscle fiber bundles. The myocardium in ventricle was denser than in the atrium. The endocardium of simple epithelial layer composed of squamous epithelial cell that had a strong basophilic nucleus was located in the center. The endocardium thickness of the atrium was $6.04({\pm}2.26){\mu}m$, endocardium thickness of the atrium was $7.36({\pm}3.21){\mu}m$, and appeared to be thicker in the ventricle. The kidney composed of numerous renal tubules. The renal tubule of simple epithelial layer composed of columnar epithelial cell with nucleus located in the basal zone and a number of cytoplasmic granules. The developed striated border was the inner epidermis.

• Journal of Chest Surgery
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• v.35 no.8
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• pp.580-583
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• 2002

Background: Obtaining precise hemodynamic and morphological information in the early postoperative period after surgical correction of congenital heart disease is important in determining the need for future medical or surgical intervention. We investigated the residual shunting after surgical repair of simple ventricular septal defect in order to know the incidence of residual shunting in the postoperative period and the natural history of small residual shunts located in the peripatch area. Material and Method: Forty three consecutive patients under one year of age who underwent patch repair of a simple ventricular septal defect were evaluated for incidence of residual shunts by echocardiography. Result: Eleven patients had echocardiographic residual shunt in the peripatch area at immediate postoperative period, however, there were no patients who needed reoperation due to deteriorated hemodynamic effect of residual shunt. The incidence of residual shunts was not significantly different with type of ventricular septal defect and material used for closure. During follow up period, two patients were lost and remaining nine patients no longer showed evidence of residual shunt. The mean time of last evidence of shunt was $4.2{\pm}3.6$ months after operation. Conclusion: Residual peripatch shunt flow was frequently noted in the immediate postoperative period following surgical repair of ventricular septal defect, however, most of them were disappeared within six months.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.119-123
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• 1999

Background: From January 1989 to December 1996, we analyzed 22 cases of ventricular septal defect associated(VSD) with aortic valvular prolapse. Material and Method: The mean age of the patients was 7 years with a range of 6 months to 22 years . Thirteen patients were male and 9 were female. The types of VSD were Kirklin type I in 13 , Kirklin type II in 8 and Kirklin type I+II in one. Result: The preoperative echocardiographic findings were aortic valvular prolapse in 10 patients, aortic valvular prolapse associated with aortic regurgitation in 6, and only aortic regurgitation in 2. Aortic valvular prolapse were found in operation field in 4 that was not be in preoperative echcardiography. Preoperative mean Qp/Qs, systolic PAP, systolic RVP were 1.48${\pm}$0.42, 27.9${\pm}$9.87, 32.9${\pm}$10.87 mmHg, respectively. Twenty patients underwent patch closure of VSD, and two patients with moderate aortic regurgitation and prolapsed of the aortic valve underwent patch closure of VSD and aortic valvuloplasty. Short and long term echocardiographic follow-up in 8 patients who had preoperative aortic regurgitation were found to have improved or not aggravated by performing VSD patch closure only and patch closure with valvuloplasty in 2. Twelve patients who had only preoperative aortic valvular prolapse had no change in prolapsed valve in postoperative echocardiography. Conclusion: Early closure of VSD with patch is necessary in VSD with aortic valvular prolapse even in associated with mild regurgitation. But in moderate regurgitation, VSD closure with valvuloplasty is recommended.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.139-145
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• 2004

This study describes our surgical results of transventricular complete repair of tetralogy of Fallot in infants. Material and Method: Eight hundred and forty children underwent complete repair of TOF between January 1990 and April 2002 in our institute. One hundred sixty infants of them were included to this survey. Mean age at repair was 8.1$\pm$2.6 months (3∼12). Correction was accomplished through a short right ventriculotomy less than 30% of ventricular height in all patients. A transannular patch was necessary in 78 patients (49%). Result: There were four early deaths. There were no late deaths. Follow-up with mean duration of 66 months was completed in all survivors, All patients are currently in New York Heart Association functional class I or II. Twenty patients required late reoperations. Actuarial freedom from reoperation at 1 and 10 years were 94% and 87% respectively. Two-dimensional and Doppler echocardiographic follow-up studies showed good right ventricular function in all patients except three. Conclusion: Our results suggested that early complete repair of TOF yield the acceptable results with low mortality and morbidity. Transventricular repair of intracardiac pathology can be safely applied to these patient population, yielding good postoperative right ventricular function.

• Journal of Chest Surgery
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• v.29 no.11
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• pp.1191-1196
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• 1996

Recently, if there is pulmonary hypertension in ventricular septal defect, early operation without pulmonary artery banding is recommended even though patient is under 1 year in age or has low body weight. We also had been performing operations under the above mentioned policy. From October 1986 to December 1995, eighty eight cases of ventricular septal defect under 10Kg in body weight were operated upon by open cardiac surgery. Mortality was compared by age, body weight and degree of pulmonary vascular hypertension. Total mortality was 10cases(11.4%); under 6months, the mortality was 5 in 14 cases(35.8%), from 6 months to 1year, 4 in 43 cases(9.3%) and over 1 year, one in 31 cases(3.2%), while there was no significant difference in mortality compared by degree of pulmonary vascular hypertension. And mortality under 6months in age was so high regardless of severity of pulmonary hypertension. After this exprience, too early operation,. especially under 6 months, should be considered very prudently, unless there were life threatning heart failure, impending irreversible pulmonary vascular bed change or failure to thrive.