• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.251-252
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• 2008

• Journal of Mechanical Science and Technology
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• 제19권6호
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• pp.1313-1320
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• 2005

Stenosed coronary artery may play an important role in various coronary heart diseases. However, it has not been known how much stenosed coronary artery affects coronary circulation system, quantitatively. The present study developed a mathematical model for microcirculation in the left common coronary artery (LCCA) with adopting a previously measured morphological data and mechanical properties of the coronary vessels. We examine the effect of percent diameter stenosis on blood flow rate and shear stress for two cases. Case I comprised of one-stenosed element at $10^{th}$ order ($\%$ diameter stenosis are 10, 30, and 50, respectively). Case II consisted of completely occluded element at $10^{th}$ order (number of occluded elements are 0, 1, and 2 out of 8, respectively). As the level of stenosis becomes severe, the shear stress increases significantly but the flow rate reduction was relatively small. However, for the occluded case, there was linearly proportional reduction of flow rate according to number of occluded elements. Either such high shear stress associated with coronary artery stenosis or reduced flow rate due to occlusion may cause atherosclerosis and myocardial ischemia.

• Journal of Chest Surgery
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• 제45권1호
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• pp.45-48
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• 2012

We report a case of a postinfarction ventricular septal defect caused by an acute recurrent occlusion after the implantation of a covered stent, which was performed as a rescue procedure for the ruptured left anterior descending artery during a percutaneous coronary intervention. Although the emergent implantation of a covered stent for the ruptured coronary arteries such as the left main coronary artery or the origins of the left anterior descending artery can be performed during a percutaneous coronary intervention, and a coronary bypass surgery should be considered in order to decrease the risk of complete occlusion, thus providing a superior long term patency.

• Nutrition Research and Practice
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• 제8권4호
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• pp.391-397
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• 2014

BACKGROUND/OBJECTIVE: Myocardial cell death due to occlusion of the coronary arteries leads to myocardial infarction, a subset of coronary heart disease (CHD). Dietary fiber is known to be associated with a reduced risk of CHD, the underlying mechanisms of which were suggested to delay the onset of occlusion by ameliorating risk factors. In this study, we tested a hypothesis that a beneficial role of dietary fiber could arise from protection of myocardial cells against ischemic injury, manifested after occlusion of the arteries. MATERIALS/METHODS: Three days after rats were fed apple pectin (AP) (with 10, 40, 100, and 400 mg/kg/day), myocardial ischemic injury was induced by 30 min-ligation of the left anterior descending coronary artery, followed by 3 hr-reperfusion. The area at risk and infarct area were evaluated using Evans blue dye and 2,3,5-triphenyltetrazolium chloride (TTC) staining, respectively. DNA nicks reflecting the extent of myocardial apoptosis were assessed by TUNEL assay. Levels of cleaved caspase-3, Bcl-2, and Bax were assessed by immunohistochemistry. RESULTS: Supplementation of AP (with 100 and 400 mg/kg/day) resulted in significantly attenuated infarct size (IS) (ratio of infarct area to area at risk) by 21.9 and 22.4%, respectively, in the AP-treated group, compared with that in the control group. This attenuation in IS showed correlation with improvement in biomarkers involved in the apoptotic cascades: reduction of apoptotic cells, inhibition of conversion of procaspase-3 to caspase-3, and increase of Bcl-2/Bax ratio, a determinant of cell fate. CONCLUSIONS: The findings indicate that supplementation of AP results in amelioration of myocardial infarction by inhibition of apoptosis. Thus, the current study suggests that intake of dietary fiber reduces the risk of CHD, not only by blocking steps leading to occlusion, but also by protecting against ischemic injury caused by occlusion of the arteries.

• Journal of Chest Surgery
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• 제30권12호
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• pp.1190-1196
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• 1997

1994년 7월부터 1995년 8월까지 서울대학교병원 흉부외과에서 시행한 관상동맥 우회술 78례 중 49례 (62,8%)에서 수술 1년 후 관상동맥 조영술을 시행하여 이식 혈관의 개존성을 조사하였으며, 수술 전,후 및 수술과 관련된 여러 위험 요소들이 개존성에 미치는 영향에 대하여 분석하였다. 관상동맥 우회술 후 평균 13.4$\pm$2.1개월 째에 관상동맥 조영술을 시행하였다. 내유동맥으로 문함을 시행한 60개소 중 3개소에서 string sign을 보였으나, 폐쇄 없이 전례에서 개존성이 유지되었으며, 요골동맥으로 문합을 시행한 4개소는 모두 개존성이 유지되었다. 복제정맥으로 문합을 시행한 81개소 중 69개소(85.2%)에서 개존성이 유지되었으며, 12개 소(14.8%)에서 폐쇄되었다. 개존성에 미치는 위험요소로 수술 전,수술 중 그리고 합병증 등의 수술 후 요소로 나누어 일원적 및 다원적으로 분석하였으며, 내유동맥의 협착 과 복재정맥의 개존성, 폐쇄에 미치는 요소들을 분석하였다. 내유동맥은 환자의 연령(60세 이상),수술 후 대동맥 내 풍선펌프의 삽입,수술 후 출혈, 및 급성신부전 등 합병증이 이식 혈관의 협착과 관련된 위험 인자였으며, 복제정맥은 우회술을 시\ulcorner 받은 관상동맥의 직경이 1.5mm 이하인 경우가 이식 혈관의 폐쇄 위험성과 관련된 위험 인자로 분석되었다(p<0.05). 관상동맥 우회술 1년 후 이식 혈관의 개존성은 내유동맥이 복재정맥보다 우수함을 보였으며 환자 연령 수술 후 대동맥 내 풍선펌프의 삽입여부, 출혈, 급성 신부전 등의 합병증 및 문합된 관상 동맥의 직경 등이 개존에 관련된 요소로 분석되었다. 이러한 결과를 토대로 수술 후 이식혈관의 폐쇄 여부에 대한 11측과 수술 방법이나 수술 후 환자의 추적 관찰에 도움을 줄 수 있으리라 생각된다.

• Clinical and Experimental Pediatrics
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• 제56권2호
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• pp.90-93
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• 2013

Congenital coronary arteriovenous fistulas (CCAFs) are rare coronary artery abnormalities in which blood is shunted into a cardiac chamber or great vessel. If the fistula itself is large and tortuous, it is generally recommended to occlude the fistula to prevent several complications. In approaches of transcatheter occlusion, the transvenous approach is preferred over the transarterial approach. The transvenous approach would enable the cannulation of a relatively larger catheter or sheath without potential damage to the femoral vessels or normal coronary arteries, which can occur in the transarterial approach. The transvenous approach may also minimize the blind pouch after releasing the devices. Herein, we report the success of transvenous proximal closure of a CCAF using an Amplatzer vascular plug (AVP) in a 3-year-old patient with cardiomegaly. Complete occlusion was achieved by a single AVP and thrombus formation of the distal aneurysmal portion of the fistula. We suggest that this strategy of closing the proximal end with a dilated fistula using a single AVP by the transvenous approach may be a good option in treating CCAFs in a young child.

• Clinical and Experimental Pediatrics
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• 제46권3호
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• pp.302-307
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• 2003

환아는 3개월된 영아로 발병 10일째에 본원에 내원하여 초기에 적절한 진단과 치료를 받지 못했으며 발병 2주에 시행한 심초음파상 거대 관상동맥류를 보였다. 이에 정맥용 면역글로불린 투여와 aspirin과 dipyridamole로 치료 중 발병 24일째 혈전증이 동반되어 urokinase와 heparin의 IV 투여를 통한 혈전용해 치료로 혈전을 완전히 제거할 수 있었다. 이후 5년간 aspirin, dipyridamole, coumadin을 투여하면서 심전도와 심초음파검사를 반복하며 외래 추적 관찰 중 점차 좌측관상동맥내 혈전이 증가하고 내경이 점차 좁아지는 소견과 함께 협착이 의심되었다. 발병 5년 후 시행한 관상동맥 혈관조영술상 관상동맥 좌측 전하지가 완전 폐색되고 우측관상동맥으로부터 발달한 측부순환에서 혈류를 공급받고 있었고, 핵의학 검사상 좌심실의 전벽과 중격, 일부 외벽에 완전 가역적 관류 결손을 보였던 가와사끼병 환아 1례를 경험하여 보고한다.

• Journal of Chest Surgery
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• 제37권7호
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• pp.570-577
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• 2004

관상동맥우회술 후 이식편의 조기 열림을 판정하기 위한 CT 조영술은 비침습적이고 간단하며 안전한 방법으로 알려져 있다. 저자들은 관상동백 우회술 환자들에서 수술 후 퇴원 전에 CT 조영술을 시행하여 이식편의 조기 열림의 판정에 대한 여부와 영상에 미치는 인자들을 조사하였다. 대상 및 방법: 관상동맥 우회술을 받은 50예에서 수술 후 퇴원 전에 4개의 검출기를 가진 CT기로 조영술을 시행하고 내흉동맥 이식편(50편), 요골동맥편(18편), 대퇴정맥편(56편)의 조영상해로 이식편의 열림을 조사하고 이식편의 조영상태와 문합혈관의 직경, 부행혈류 및 협착정도와의 관계를 분석하였다. 결과: 좌관상동맥계에 문합되는 정맥편(24편, 32문합부)은 모두 잘 조영되었으나, 우관상동백계에 문합된 정맥편(30편, 35문합부) 중 3편 (4.7%)은 CT 조영술에서 조영되지 않았고 대퇴동맥을 통한 침습적인 관상동맥 조영술에서도 폐쇄된 소견을 보였다. 내흉동맥편 중 39편(78%)은 CT 조영술에서 잘 조영되었고 8편(16%)은 일부 좁아지거나 끊기는 불완전한 조영을 보였으며 3편(6%)은 조영되지 않았으나 동맥을 통한 침습적인 관상동맥 조영술에서는 모두 정상적인 열림 소견을 보였다. 결론: 관상동맥조영술 후 CT 조영술에서 조영되지 않는 정맥편은 페쇄를 의미하나, CT조영술에서 조영되지 않는 동맥편은 폐쇄가 아닌 관상동맥과 이식편 사이의 상경혈류 때문에 일어날 수 있으므로 조영이 안 되는 동맥편의 열림을 확인하기 위해서는 침습적인 관상동맥조영술이 필요할 것으로 생각된다.

• 한국임상약학회지
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• 제6권2호
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• pp.32-40
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• 1996

The electrophysiological effects of benzopyran potassium channel openers (PCOs: lemakalim, KR-30450 and KR-30818) on the ischemia/reperfusion-induced arrythmias were investigated. In anesthetized rats, subjected to 45 min occlusion of the left anterior descending coronary artery (LAD) followed by 90 min reperfusion, ventricular arrythmias were identified according to the Lambeth Conventions by lead II ECG. Rats were intravenously given vehicle ($1\%$ DMSO), lemakalim, KR-30450, and KR-30818 alone or in combination with a selective $K_{ATP}$ blocker glibenclamide, 30 min prior to coronary occlusion. Compared to vehicle, lemakalim ($30{\mu}g/kg$ i.v.), the active enantiomer of cromakalim, had a tendancy to increase the duration of ventricular tachycardia (Vl) and ventricular fibrillation (VF), the number of premature ventricular complexes (PVC) and the incidence of VF, especially in the early post-occlusion peroid ($0\~15$ min), while increasing ST-segment elevation. Both KR-30450 ($30{\mu}g/kg$, i.v.) and KR-30818 (30, $100{\mu}g/kg$, i.v.) showed similar proarrhythmic effects to lemakalim (PVC, duration of VT, and incidence of VF) with a tendancy to decrease the duration of VF and ST-segment elevation. Unlike other PCOs, however, glibenclamide (0.3, 1.0 mg/kg) had opposite effects on the induction of arrhythmias (PVC, the duration of VF); it had a tendancy to increase the duration of VT with a slight elevation of ST-segment. It seems likely that glibenclamide (0.3 mg/kg, i.v.), reduced the effects of lemakalim or KR-30450 ($30{\mu}g/kg$, i.v.) on arrhythmias (PVC, VT, VF and ST-segment). These results indicate that, in the coronary occluded rat model of ischemia, lemikuiln and KR-30450 exert a proarrhythmic activity, the effect being considered related to the opening of KATP channel.

• 약학회지
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• 제41권1호
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• pp.117-125
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• 1997

The pharmacological effects of benzopyran potassium channel openers (lemakalim, KR-30450 and KR-30818) on the occlusion/reperfusion-induced myocardial infarction were investigat ed. In anesthetized rats, subjected to 45-min occlusion of the left anterior descending coronary artery (LAD) followed by 90-min reperfusion, the infarct size was measured by calculating the ratio of infarct zone to area at risk (IZ/AAR) with the Evans blue/TTC technique. Rats were intravenously given vehicle (1% DMSO), lemakalim, KR-30450, and KR-30818 alone or in combination with a selective K$_{ATP}$ blacker glibenclamide, 30 min prior to coronary occlusion. Compared to vehicle, lemakalim (30 ${\mu}$g/kg i.v.), the active enantiomer of cromakalim, had a tendancy to decrease infarct size. KR-30450(30 ${\mu}$g/kg, i.v.). the newly synthetized potassium channel openers (PCOs), caused a reduction of infarct size (from 70${\pm}$4%to 57${\pm}$5%). but KR-30818 (30 ${\mu}$g/kg, i.v.), a metabolite of KR-30450. did not modify infarct size. It seem ed likely that glibenclamide (0.3mg/kg, i.v.), given in combination, reduced the effects of these PCOs, especially KR-30450 (30 ${\mu}$g/kg, i.v.) on the infarct size. These results indicate that. in the coronary occluded rat model of ischemia, lemakalim and KR-30450 may exert cardioprotective activity through a reduction of infarct size, the effect being considered related to the opening of K$_{ATP}$ channel.