• Journal of Biomedical Engineering Research
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• v.36 no.4
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• pp.135-142
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• 2015

Outflow cannulation site of left ventricular assist device(LVAD) chosen by considering anatomical structure of thoracic cavity and vascular system. Though outflow cannulation site influences blood perfusion at each branch, there is no standard rule or quantitative data. In this study, we computed the amount of blood perfusion at each arterial branch numerically according to outflow cannulation sites(ascending aorta, aortic arch, descending aorta). We generated computational meshes to the three-dimensionally reconstructed arterial system. Clinically measured arterial pressure were used for inlet boundary condition, porous media were applied to mimic blood flow resistance. Blood perfusion through left common carotid artery was 2.5 times higher than other cases, and that through right common carotid artery was 1.1 times higher than other branches. Although this is simulation study, will be useful reference data for the clinical study of LVAD which considers blood perfusion efficiency.

• Applied Microscopy
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• v.19 no.2
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• pp.85-98
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• 1989

The ventricular myocardia of 14, 16, 18 and 20-day-old rat fetuses and newborns have been studies by light and electron microscopic morphometrics. The volume density of the myocyte and interstitial compartments as well as volume, surface and numerical density of nuclei were estimated by light microscopic morphometrics. Whereas, the volume density of myofibrils and glycogen granules as well as the volume, surface and numerical density of mitochondria were assessed by electron microscopic morphometrics. The volume density of myocyte compartment of the ventricular myocardia in developing fetuses decreased, but increased in newborn rats. On the other hand, the volume density of the interstitial compartment increased in growing fetuses and decreased in newborns. In all groups the volume, surface and numerical density of nuclei decreased gradually with elongation of myocytes. Conversely, the volume, surface and numerical density of mitochondria and volume density of myofibrils and glycogen granules in ventricular myocytes incresed. The increase in numerical density of mitochondria probably reflects an increase in metabolic activity. Sarcomere length also increased during development.

• Journal of Chest Surgery
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• v.19 no.4
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• pp.627-632
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• 1986

This report describes our 17-years experience with intracardiac repair in 123 patients older than 15 years with tetralogy of Fallot. Major clinical manifestation was cyanosis and clubbing [102 Pts], but other minor associated manifestation were infective endocarditis, pulmonary tuberculosis, brain abscess, congestive heart failure, nephrotic syndrome, and tuberculous spondylitis. Prior palliative shunts had been performed in 10 patients. Preoperative hemoglobin ranged from 9.7 gm/dl to 25 gm/dl [mean 19 gm/dl]. The type of ventricular septal defect were typical perimembranous type, and total canal defect [13%]. The right ventricular outflow tract obstruction was due to combined [58.5%], infundibular [35%], and valvular stenosis [6.5%]. Transannular patch was used in 17% of patients. Hospital mortality was 9.8% in overall, but decreased to 1.7% since 1982. There was two late death [12 year actuarial survival [97%] due to fulminant hepatitis, residual abnormalities [PS, VSD]. Ninety two percent of survivors at follow-up are asymptomatic and leading an active normal life. Residual ventricular septal defect was detected with radionuclide single pass study in 15.3% of patients but almost cases were Qp/Qs less than 1.5, and only two patients had been candidates for reoperation.

• Journal of Chest Surgery
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• v.22 no.2
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• pp.234-245
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• 1989

Between January 1984 and December 1986, sixty nine patients, aged 16 months to 25 years [mean age 10.05*6.40 years], underwent total correction of tetralogy of Fallot in Kyungpook national university hospital. In 66 hospital survivors, 30 patients were followed up for 12 to 48 months [mean 30.10*10.26 months]. These 30 patients were classified in two groups, TAP [transannular patch] and Non-TAP group. There were 9 patients in TAP group, and 21 in Non-TAP group. There were no significant differences between two groups in terms of age at operation, follow up duration, ACC time, and bypass time. All patients were evaluated by two dimensional echocardiography, Doppler echocardiography, standard 12-lead electrocardiography, and plain chest X-ray. Right ventricular systolic pressure, pulmonary arterial systolic pressure, pressure gradient between the right ventricle and the pulmonary artery, presence or absence of pulmonary regurgitation and its grading, fractional shortening of the left ventricle, and Qp/Qs in case of remnant ventricular septal defect were obtained by echocardiographic examination. Cardiothoracic ratio was measured by plain chest film, and ventricular dysrrhythmia was detected by electrocardiogram. Comparing the data between two groups, there was significant difference in incidence of postoperative pulmonary regurgitation [p< 0.05], 100%[9/9] in TAP group and 47.6 %[10/21] in Non-TAP group, but all the regurgitations were not severe. There were no significant differences in other comparisons, despite of higher incidence of cardiomegaly in TAP group [CT ratio: 59.3*5.3% VS 54.7*6, 4 %].

• Journal of Chest Surgery
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• v.45 no.2
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• pp.116-119
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• 2012

A 61-year-old female patient was diagnosed with dilated cardiomyopathy with severe left ventricle dysfunction. Two days after admission, continuous renal replacement therapy was performed due to oliguria and lactic acidosis. On the fifth day, an intra-aortic balloon pump was inserted due to low cardiac output syndrome. Beginning 4 days after admission, she was supported for 15 days thereafter with an extracorporeal left ventricular assist device (LVAD) because of heart failure with multi-organ failure. A heart transplant was performed while the patient was stabilized with the LVAD. She developed several complications after the surgery, such as cytomegalovirus pneumonia, pulmonary tuberculosis, wound dehiscence, and H1N1 infection. On postoperative day 19, she was discharged from the hospital with close follow-up and treatment for infection. She received follow-up care for 10 months without any immune rejection reaction.

• Journal of Internet Computing and Services
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• v.8 no.1
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• pp.125-132
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• 2007

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 eight most important coefficients of d3 and d4 are selected by the non-overlap area distribution measurement method. The selected 8 coefficients are used for 3 data sets showing reliable accuracy rates 99,80%, 99,21%, and 98.78%, respectively, which means the selected input features are less dependent to the data sets. The ECG signal segments and fuzzy membership functions of the 8 coefficients enable input features to interpret explicitly.

• Journal of Chest Surgery
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• v.16 no.4
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• pp.476-484
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• 1983

Ventricular septal defect[VSD] associated with aortic regurgitation[AR] represents 2 to 7.5% of all VSD which is most common congenital heart disease. The aortic valve may by normal in infants with VSD, but the aortic regurgitation may be developed in these patients later. The aortic valve became fibrotic, thickened, deformed and prolapsed, so these late deformities require to be corrected with plication, valvuloplasty or aortic valve replacement [AVR]. There are some controversy between the early repair of VSD alone and the late repair of VSD and aortic valve till now. From December 1971 to August 1983, we had experienced 24 patients of VSD associated with AR which constitute 6.5% of our total patients with VSD. The VSD was subpulmoary [type I] in 14[58.3%], subcristal [type II] in 8[33.3%], atrioventricular canal type[type III] in 1, and combine of type I and II in 1. Patch repair of VSD was made in 15 patients and direct suture of small VSD in 9.14 patients had aortic plication of valvuloplasty and 9 had AVR accompanying VSD repair, and 1 patient had VSD closure alone. The postoperative courses of these patients were uneventful except in some cases. A patient who was undertaken AVR with Starr-Edwards ball valve and VSD closure, died due to left ventricular failure and low cardiac output syndrome. Follow up shows, in 14 patients with aortic plication or valvuloplasty, AR was developed in 9. In 9 AVR, there were two later complications which were paravalvular leakage in one and re-AVR due to subacute bacterial endocarditis in another.

• Journal of Chest Surgery
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• v.13 no.1
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• pp.1-12
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• 1980

In 1979 during the period of about 10 months 320 cases of open heart surgery were done in Seoul National University Hospital. There were 220 Congenital anomaly cases consisting of 113 acyanotic and 107 cyanotic varieties, and 1 O0 acquired cardiac lesions. Out of 100 acquired lesions 96 were valvular cues. Among 97 valve replacement cases 3 were Ebstein anomaly treated with plication and tricuspid valve replacement. Operative mortality rate for congenital anomaly was 10.6%, with 2.7% for acyanotic and 22.4% for cyanotic group. For acquired lesions over all operative mortality was 7%. Tetralogy of Fallot, ventricular septal defect, and atrial septal defect were the 3 main congenital anomalies, with 88 cues, 69 cases, and 27 cues respectively. In 61 simple ventricular septal defect without other anomalies operative mortality rate was 1.6%, in 27 atrial septal defect no death and, in tetralogy of Fallot 12.2%. Among 69 ventricular septal defect cases 19[27.5%] type I VSDs, after Kirklin-Becu classification, were found, rather high relative incidence of type I compared with Caucasian patients. Among 97 valve replacement cases 20 double valves were replaced-11 mitral with aortic and 9 mitral with tricuspid valves. Over all operative mortality rate for valve replacement was 8.2% with 3.3% in 61 mitral valve replace-merit. The over all operative mortality rate for 320 open heart surgery cases was 10.6%. Bubble type oxygenator and xenograft bioprosthetic valves were utilized In almost all cases.

• Journal of Chest Surgery
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• v.27 no.1
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• pp.24-30
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• 1994

Eighteen infants with a large ventricular septal defect[VSD] underwent primary surgical repair from January 1986 to December 1992. Operation was done because of failure to thrive, medically intractable heart failure, recurrent pneumonia, increased pulmonary vascular resistance[PVR]. Four patients[22.2%] died in the early postoperative period. Relief of heart failure and normalization of growth and weight gain was evident in all survivor. There was no late postoperative death. The results of primary surgical repair of VSD in infancy are compared with those of palliative pulmonary artery banding[PAB] and of VSD closure after PAB. Twenty-seven patients with isolated VSD or with VSD associated with atrial septal defect, patent ductus arteriosus, or coarctation of the aorta underwent initial palliative PAB. There were 3 early postoperative deaths[11.1%]. Severe elevation of PVR persisted in two patients. Closure of VSD and pulmonary artery debanding was done in twenty patients, with 2 early postoperative deaths[10.0%]. Placement of the PAB too close to the pulmonary annulus necessitated trasannular patching in one patient, but any problem caused by migration of the band was not developed. It is concluded that primary surgical repair of VSD in infancy is reasonable and that PAB is indicated only for those patients less than 6 months old with a complicated defect or in an emergency situation.

• Journal of Chest Surgery
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• v.44 no.2
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• pp.186-188
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• 2011

Ventricular septal rupture (VSR) is a rare but lethal complication of myocardial infarction. The event occurs 2~8 days after an infarction and often precipitates cardiogenic shock. Post myocardial infarction VSR is known for difficult to repair. Especially, Transmural myocardial infarction involved in the posterior VSD area, exposure of the affected site is difficult and postoperative mortality rate is high. We have experienced a case of a 75-year-old female patient who suffered posterior VSD due to acute myocardial infarction, and attained good result by approaching the lesion through right atrial incision and repaired the defect by using patch closure technique.