• Journal of Chest Surgery
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• v.40 no.3 s.272
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• pp.168-179
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• 2007

Background: The recent trend of an increasing number of patients with acute cardiogenic shock or chronic congestive heart failure following myocardial infarction, as well as the considerable number who can not be weaned from cardiopulmonary bypass after open heart surgery, call for immediate efforts to develop affordable ventricular assist devices that are suitable for the Korean physique. Recently, a pneumatic pulsatile ventricular assist device (VAD), named DKUH-75, has been developed by the Department of Biomedical Engineering, in collaboration with the Department of Thoracic and Cardiovascular Surgery of Dankook University College of Medicine. The feasibility of the DKUH-75 VAD was evaluated on the bases of common hemodynamic variables and echocardiographic measurements in pigs, which are subjected to an acute cardiogenic shock state following myocardial infarction, using a novel coronary artery ligation method employing the ischemic preconditioning concept. Material and Method: Acute cardiogenic shock was induced in 10 Yorkshire Landrace Duroc strain pigs by ligating the left anterior descending coronary artery via an ischemic preconditioning process. The hemodynamic variables were monitored, with epicardial echocardiographic measurements performed before and one hour after the ligation. The DKUH-75 VAD was implanted into 5 pigs one hour after the onset of the shock. The hemodynamic variables and echocardiographic measurements were taken one hour after installation of the VAD. Result: The systolic, diastolic and mean systemic arterial pressures were significantly decreased in all the experimental animals one hour after the ligation. The systolic, diastolic and mean pulmonary arterial pressures were increased (Eds note: this completely contradicts the preceding statement? However, if you mean the non-experimental animals this should be stated?). The left ventricular end diastolic pressure (LVEDP) was increased, but the cardiac index decreased, An increase in the left ventricular end systolic dimension and decreases in the fractional shortening and ejection fraction were observed all animals one hour after the coronary artery ligation. In all 5 of the VAD implanted pigs, the systolic and mean systemic arterial pressures were increased, and the pulmonary arterial pressures decreased one hour after the implantation; the LVEDP decreased, but the cardiac index was significantly increased, In the echocardiographic measurements, the left ventricular end systolic dimension decreased after the implantation of the VAD, but the fractional shortening and ejection fraction significantly increased. Conclusion: Significant improvements in the hemodynamic variables and echocardiographic measurements were observed in the 5 VAD implanted animals one hour after installation, which had been subjected to an acute cardiogenic shock state by ligation of the coronary artery, indicating that the DKUH-75 VAD could help in the recovery of the myocardial function. This suggests that the DKUH-75 VAD is feasible in the short term in relation to an acute cardiogenic shock state due to myocardial infarction.

• Journal of the korean veterinary medical association
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• v.41 no.12
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• pp.1142-1147
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• 2005

생명체 안에는 정맥혈과 동맥혈이라는 두 가지 종류의 혈액이 흐른다. 여기에는 신체 내 세 가지 기관이 관여하는데, 간은 영양과 성장의 임무를 심장은 생명의 원동력을 뇌는 인지와 이성을 담당한다. 영양과 성장은 간에서 형성되는 '정맥혈'을 통해 형성되고 생명의 원동력은 심장에서 형성되는 '동맥혈'을 통해 전신으로 퍼진다. 이 혈액들은 심장으로 다시 돌아오지 않고 온 몸에 퍼져 소비된다. 혈액은 심장이 이완될 때 심장 안으로 빨아들여진다. 심장은 혈액을 펌프질하는 기능이 없으며 동맥이 그 스스로가 '박동성'을 가지고 혈액을 밀어낸다. 좌심실에서 정맥혈과 프네우마(Pneuma)가 섞이게 되는데 심장 오른쪽 심실과 심방의 정맥혈은 좌심실과 우심실 사이 중격(심실중격, interventricularseptum)의 작은 구멍을 통해 좌심실로 이동한다.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.653-655
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• 2017

심근섬유증은 심장에서 전도 장애를 일으키며 심부전증상을 발생시킨다. 심근섬유증으로 인한 심장박동현상의 변화를 확인하기 위해 시뮬레이션 연구를 진행하였다. 심실의 유한요소 모델을 설계하고 무작위로 전도 블록을 생성하여 심근섬유증을 적용하고 그 비율을 조절하였다. 심근섬유증의 비율에 따라 전기생리학적 시뮬레이션을 진행하고 그 결과를 바탕으로 기계 수축 시뮬레이션을 진행하여 심실의 수축 변화를 확인하였다. 심근섬유증의 비율이 증가할수록 좌심실의 압력이 감소하고 박출되는 혈액량과 박출계수, 심장박동의 효율이 감소하였다.

• Journal of Chest Surgery
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• v.33 no.11
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• pp.906-909
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• 2000

심폐바이패스를 사용하지 않고 심장박동 상태에서 시행하는 관상동맥 우회수술은 심 비대와 좌심실 기능저하가 동반된 협증심 환자에서는 심장 뒤쪽에 위치한 관상동맥에 대한 접근이 어렵고 수술 중 혈역학적으로 불안정하여 시행하기에 어려운 경우가 많다. 우심실 보조장치 하의 심장박동 상태에서 시행하는 관상동맥 우회수술은 대동맥의 삽관을 피하고, 심폐바이패스의 합병증을 줄일 수 있으며, 심장 뒤쪽에 위치한 혈관의 문합시에도 안정된 혈역학적 상태를 유지 할 수 있어 고위험군 환자에게 도움을 줄 수 있다. 좌심실 기능저하와 심 비대가 동반된 환자에서 우심실 보조장치 하의 심장박동 상태에서 시행한 관상동맥 우회수술을 2례 시행하여 좋은 결과를 얻어 보고하고자 한다.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.662-664
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• 2017

심실 내부에 가해지는 수축력에 의해 심실 내부 벽에는 큰 무리가 될 수 있다. 이로 인해 다양한 심장질환인 부정맥, 심실 세동 등을 유발한다. 따라서 본 연구에서는 가상 심장모델을 구축하여 컴퓨터 시뮬레이션을 통한 수축이완시의 심장 상태를 살펴보고자 하였다. 이를 위해서 개 심장 모델을 활용하여 3차원으로 이뤄진 심장모델을 구현하였다. 심장모델의 전기생리학 기전에 기초한 전기전도 해석을 수행하고, 전기전도 해석 시 발생되는 칼슘이온의 농도변화를 활용하였다. 시간에 따른 칼슘 이온의 심장 수축 영향을 바탕으로 비선형 유한요소법을 이용, 3차원 심장의 수축역학을 해석하였다. 이러한 기전으로 심장 근육에 부하되는 응력(tension)를 계산하고, 이렇게 계산된 심근의 응력분포에 대해 관측 및 분석을 진행하였다.

• Proceedings of the KTCVS Conference
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• 1995.10a
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• pp.44-44
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• 1995

• Proceedings of the KTCVS Conference
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• 1996.10a
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• pp.39-40
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• 1996

• Journal of Chest Surgery
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• v.36 no.7
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• pp.523-526
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• 2003

A 44-year-old man had been admitted for dyspnea on exertion and abdominal distension. The echocardiography revealed abnormal mass in right atrium and tricuspid valve stenosis with right ventricular obliteration. The operation was performed with mass removal, enlargement of tricuspid valve opening, and right ventricular endocardiectormy. And then, atrial septal defect was made due to inadequate right ventricular volume. The patient's symptom was improved and he discharged without events. The endomyocardial fibrosis was diagnosed with microscopic examination. Eighteen months later, the patient was readmitted due to aggravated dyspnea and cyanosis. The right ventricular obliteration was progressed and pulmonary blood flow was severely decreased in follow up echocardiography. Palliative bidirectional cave-pulmonary shunt was performed due to functional single ventricle. The dyspnea and cyanosis was markedly improved. Bidirectional cavo-pulmonary shunt for advanced and isolated right ventricular endomyocardial fibrosis provided effective palliation at early postoperative period, However, long-term follow up is mandatory.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.200-204
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• 1997

This is a report of a successful management of a patient with infective endocarditis involving native aortic valve, mitral valve, tricuspid valve, and Interventric lar septum. A 16 year-old patient who underwent VSD patch closure, and aortic valvuloplasty at the age of 1 1 years showed Intractable congestive heart failure during antibiotics treatment for infective endocarditis. Operative findings revealed that there were large defect along the previous patch, aortic regurgitation with multiple perforations and vegetations, mitral regurgitation with vegetation, aortic paraannular abscess, interventricular myocardial abscess, and tricuspid regurgitation with perforations and vegetations. We reconstructed the interventricular defect with Dacron patch extending to the aortic valve annulus after radical debridement of all infected or devitalized tissues, and could implant aortic valve by anchoring to the reconstructed Dacron patch. Mitral valve was replaced and tricuspid valve was repaired with patient's own pericardium. The patient was discharged after antibiotics treatment for 6 weeks and in good condition without any sequelae for 12 months.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.516-519
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• 2009

Ventricular septal defect (VSD) complicating an acute myocardial infarction is rather uncommon. However, the outcomes after the development of a VSD are poor with an in-hospital mortality of more than 90% for the medically treated patients. To prevent the recurrence of VSD, many techniques have been reported on for the closure of a postinfarction VSD. In this. report, we present a case of a patient who had a postinfarction VSD due to Prinzmetai's variant angina, and the rupture of the pseudoaneurysm of the left ventricle was successfully treated by the "Sandwich technique".