• 대한통합의학회지
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• 제8권1호
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• pp.125-135
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• 2020

Purpose : Obesity indices are major predictive markers for coronary artery stenosis, but there are few studies about the relationship between obesity indices and coronary artery stenosis in the Korean population. Therefore, we analyzed the association between obesity indices and coronary artery stenosis among health-screen examinees. Methods : This study included 99 males and females who visited a health-examination center. The obesity indices included body mass index (BMI), waist circumference (WC), visceral adipose tissue (VAT), visceral adipose tissue/subcutaneous adipose tissue ratio (V/S ratio). All subjects had their degree of coronary artery stenosis measured using coronary computed tomography angiography (CCTA). A multiple logistic regression test was conducted to analyze the association between obesity indices and coronary artery stenosis. Results : This study was taken by multiple logistic regression test adjusted by age, sex, smoking status, frequency of alcohol drinking/week and frequency of exercise/week. The adjusted odds ratio for the presence of coronary artery stenosis for subjects with abdominal obesity (abdominal obesity defined as a waist circumference ≥ 90 cm in males; ≥ 85 cm in females) was 6.263 (95 % confidence interval (CI) 1.974-19.869), for subjects with visceral obesity by visceral adipose tissue (visceral obesity defined as a visceral adipose tissue ≥ 100) was 11.430 (95 % CI 3.044-42.928). Conclusion : In this study of adults, WC and VAT were independent predictors of coronary artery stenosis. These results suggest that WC and VAT may be useful markers of coronary artery stenosis.

• Journal of Chest Surgery
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• 제28권9호
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• pp.876-880
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• 1995

The optimal surgical approach to the patients with coronary artery disease combined with carotid artery stenosis is controversial. We report two cases of successful surgical management of the patients with combined obstructive coronary and carotid artery disease. The first case was a 69-year-old female who had unstable angina pectoris and a past medical history of left carotid endarterectomy. She was revealed to have triple vessel coronary disease and nearly total occlusion of right internal carotid artery. She was undergone staged right carotid endarterectomy 10 days before coronary bypass surgery. The second case, a 54-year-old male with a past medical history of left hemiparesis and dysarthria, was admitted due to unstable angina pectoris. He was revealed to have triple-vessel coronary disease and more than 90% stenosis of left internal carotid artery and 50% stenosis of right internal carotid artery. In the latter case, a combined coronary bypass surgery and left carotid endarterectomy was done. In both cases, postoperative neurologic complications were not observed.

• 정신신체의학
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• 제6권2호
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• pp.126-135
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• 1998

The object of this study was to investigate the relationship between stress and the extent of coronary artery stenosis in 101 patients with coronary artery diseases. Global assessment of recent stress(GARS) scale and perceived stress response inventory were used to measure perception for stressors and stress responses. Biological variables such as the extent of coronary artery stenosis, the number of the affected lesions on coronary angiography, serum Low Density Lipoprotein(LDL)-cholesterol, High Density Lipoprotein(HDL)-cholesterol, and total cholesterol were measured in all the subjects. Scores of perceived stress related to changes in relationship and overall global scores on GARS scale had significantly positive correlation with the extent of coronary artery stenosis. On the other hand, scores of percieved stress related to changes in relationship and changes or no changes in routine had significantly positive correlation with the number of the lesions. Scores of perceived stress related to change or no change in routine also positively correlated with serum level of LDL-cholesterol and total cholesterol. In contrast, general somatic symptoms negatively correlated with the extent of coronary artery stenosis. Impulsive-aggressive behavior negatively correlated with the number of the lesions. However, impulsive-aggressive thinking positively correlated with LDL-cholesterol. The above results suggest that perception for stressors may negatively affect the extent of coronary artery stenosis, the number of the lesions, serum LDL-cholesterol and total cholesterol. However, some stress responses showed inconsistent effect on the above biological variables. Thus, strategies designed to modify perception for stressors and some stress responses are likely to help the patients minimize the extent of coronary artery stenosis and prevent the diseases.

• Journal of Chest Surgery
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• 제27권3호
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• pp.191-195
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• 1994

Twenty-four patients with left main coronary artery stenosis exceeding 50% underwent coronary artery bypass grafting from January 1991 through June 1993. Four patients [17%] had stenosis only in left main coronary artery and 20 patients [83%] had associate lesion[s] in left anterior descending , circumflex, or right coronary artery. Sixteen patients [67%] had higher degrees of stenosis [>70%] in left main coronary artery. Preoperatively 18 patients [75%] had unstable angina pectoris even during aggressive medical treatment. Preoperatively aggressive medical treatment was performed to relieve the symptom in patients with unstable angina. All patients were perioperatively treated with continuous infusion of isosorbide dinitrate to stabilize symptomatic and hemodynamic states. Twenty patients underwent elective coronary bypass surgery and 4 patients urgent operations due to severe unstable angina. There was no thirty-day mortality or late death. Angina recurred in 1 patient, but coronary angiographic study showed good patency of grafts and the symptom was relieved with medical treatment. We concluded that coronary artery bypass grafting can be safely performed by perioperative efforts, including continuous infusion of isosorbide dinitrate, for hemodynamic stabilization in patients with left main coronary artery stenosis.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.585-590
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• 2001

The hemodynamic characteristics were compared using commercial CFD code for the stenosed coronary and abdominal arteries. Numerical calculations were carried out in the axisymmetric arteries over the stenotic diameter ratios ranging from 0.25 to 0.875 (6 cases) employing the typical physiological flow conditions. In case of the coronary artery, there was only one recirculation zone observed distal to the stenosis throat during the major portion of the period. However, in case of the abdominal aorta, there were complex recirculation regions found proximal and distal to stenosis throat. For both models, the wall shear stresses(WSS) increased sharply in the converging stenosis, reaching a peak just upstream of the throat, and became negative or low values in the post-stenotic recirculation region. As the results, the oscillatory shear index(OSI) was abruptly increased at the stenosis throat. For the coronary stenosis model, the second peak in the OSI was observed distal to the stenosis. The distance between the first peak and the second peak was increased as the degree of the stenosis was raised. On the orther hand, the abdominal stenosis model showed a complex oscillatory behavior in the OSI index and did not showed such a strong second peak. As the degree of stenosis was increased, recirculation regions of the both arteries were extended much longer and flow pattern became more complex.

• International Journal of Vascular Biomedical Engineering
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• 제1권1호
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• pp.13-23
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• 2003

Backgrounds: The present study in angulated coronary stenosis was to evaluate the influence of velocity and wall shear stress (WSS) on coronary atherosclerosis, the changes of hemodynamic indices following coronary stenting, as well as their effect of evolving in-stent restenosis using human in vivo hemodynamic parameters and computed simulation quantitatively and qualitatively. Methods: Initial and follow-up coronary angiographies in the patients with angulated coronary stenosis were performed (n=80). Optimal coronary stenting in angulated coronary stenosis had two models: < 50 % angle changed(model 1, n=43), > 50% angle changed group (model 2, n=37) according to percent change of vascular angle between pre- and post-intracoronary stenting. Flow-velocity wave obtained from in vivo intracoronary Doppler study data was used for in vitro numerical simulation. Spatial and temporal patterns of velocity vector and recirculation area were drawn throughout the selected segment of coronary models. WSS of pre/post-intracoronary stenting were calculated from three-dimensional computer simulation. Results: Follow-up coronary angiogram demonstrated significant difference in the percent of diameter stenosis between two groups (group 1: $40.3{\pm}30.2$ vs. group 2: $25.5{\pm}22.5%$, p<0.05). Negative WSS area on 3D simulation, which is consistent with re-circulation area of velocity vector, was noted on the inner wall of post-stenotic area before stenting. The negative WSS was disappeared after stenting. High spatial and temporal WSS before stenting fell into within physiologic WSS after stenting. This finding was prominent in Model 2 (p<0.01) Conclusions: The present study suggests that hemodynamic forces exerted by pulsatile coronary circulation termed as WSS might affect on the evolution of atherosclerosis within the angulated vascular curvature. Moreover, geometric change, such as angular difference between pre / post-intracoronary stenting might give proper information of optimal hemodynamic charateristics for vascular repair after stenting.

• 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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• 제27권6호
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• pp.472-476
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• 1994

The incidence of single coronary artery is extremely rare in a review of congenital anomalies of the coronary arteries. This 27-year-old male patient was referred for the evaluation of cardiac condition showing exertional dyspnea[NYHA class II-III] and chest discomfort for about 1 year. A complete catheterization study including angiogram disclosed large single coronary artery arising from left aortic sinus [Ogden classification L-4] associated with bicuspid aortic valvular stenosis and low grade supravalvular aortic stenosis. Calcified stenotic aortic valve was fully removed with caution and the 19mm St. Jude Medical valve was then implanted in the small nortic annulus. The patient had an uneventful recovery and was discharged on 13th postoperative day.

• Journal of Chest Surgery
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• 제28권4호
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• pp.409-411
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• 1995

One patient developing left main coronary stenosis following double valve replacement is reviewed. Angina pectoris developed 5 months postoperatively. Coronary perfusion with a balloon tip perfusion catheter was performed during previous operation and was considered technically satisfactory. Coronary angiography confirmed stenosis of the left main coronary artery. There was no further coronary arterial disease. An anterior approach between the aorta and pulmonary artery to expose the left main coronary artery was used and patch angioplasty was done. Repeat coronary angiography showed a widely patent left main coronary artery with excellent runoff. A careful search for coronary arterial injury should be made in all symptomatic patients following aortic valve replacement.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1999년도 추계 학술대회논문집
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• pp.152-157
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• 1999

For the simulation of the blood flow in coronary artery, the system modeling of coronary hemodynamics is combined with CFD technique. The blood flow in coronary artery interacts with the global coronary circulation. Especially in case of the coronary artery with stenosis, the interaction plays an important role in the hemodynamics of the circulation. In this study we present a combined numerical approach using both the CFD technique for flow simulation and the global system model of coronary circulation. We use a lumped parameter model for the global simulation of coronary circulation whereas the finite element method is employed to compute the viscous flow field in stenosed coronary artery, The time variation of the pressure drop due to stenosis is obtained from the proposed numerical method. Numerical results shows that the flow resistance and pressure drop due to stenosis has a relatively large value in systole.