• International Journal of Vascular Biomedical Engineering
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• v.3 no.2
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• pp.10-16
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• 2005

Because patients with coronary artery disease (CAD) have depressed vagal modulation and the mortality risk from acute myocardial infarction is lower in patients with higher vagal modulation, methods that can increase vagal modulation are desirable in patients with CAD. We intended to inspect the effect of recumbent posture on vagal modulation. By using angiography, 33 patients with abnormal (CAD group) and 33 patients with normal coronary arteries (control group) were studied. The nonlinear as well as the linear characteristics of heart rate variability (HRV) were analyzed on these patients in three recumbent postures: namely, the supine, right lateral decubitus, and left lateral decubitus postures. The lower the normalized high-frequency power (nHF) in the supine or left lateral decubitus posture, the higher the increase in the nHF when the posture was changed from supine or left lateral decubitus to right lateral decubitus in both groups of patients. Right lateral decubitus posture can lead to the highest vagal modulation and the lowest sympathetic modulation among the three recumbent postures in both normal and patients with CAD. Therefore, the right lateral decubitus posture can be used as an effective physiologic vagal enhancer in patients with CAD.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.639-655
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• 1996

Cerebrovascular disease and coronary heart disease are the first and the fourth common causes of death among adults in Korea. Reported risk factors of these diseases are mostly alike. But some risk factors of one of these diseases may prevent other diseases. Therefore, we tried to compare and discriminate the risk factors of these diseases. We recruited four case groups and four control groups among the inpatients who were admitted to Wonju Christian Hospital from March, 1994 to November, 1995. Four control groups were matched with each of four case groups by age and sex. The number of patients in each of four case and control groups were 106 and 168 for acute myocardial infarction(AMI), 84 and 133 for subarachnoid hemorrhage(SAH), 102 and 148 for intracerebral hemorrhage(ICH), and 91 and 182 for ischemic stroke(IS) respectively. Factors whose levels were significantly higher in AMI and IS than in responding control group (RCG) were education, economic status, and triglyceride. Factors whose levels were significantly lower in hemorrhagic stroke than in RCG were age of monarch, and prothrombin time. The factor whose level was higher in AMI than ill RCG was uric acid. The factor whose level was higher in AMI, ICH, and SAM than in RCG was blood sugar. Factors whose levels were significantly higher in all the case groups than in RCG were earlobe crease, Quetelet index, white blood cell count, hemoglobin, hematocrit, and total cholesterol. The list of risk factors were somewhat different among the four diseases, though none of the risk factors to the one disease except prothrombin time acted as a preventive factor to the other diseases. The percent of grouped cases correctly classified was higher in the discrimination of ischemic diseases(AMI and IS) from hemorrhagic diseases(SAM and ICH) than in the discrimination of cerebrovascular disease from AMI. The factors concerned in the discrimination of ischemic diseases from hemorrhagic diseases were prothrombin time, earlobe crease, gender, age, uric acid, education, albumin, hemoglobin, the history of taking steroid, total cholesterol, and hematocrit according to the selection order through forward selection.

• Korean Journal of Adult Nursing
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• v.20 no.6
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• pp.917-931
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• 2008

Purpose: This study was aimed to determine the optimum low-density lipoprotein : high-density lipoprotein-cholesterol (LDL : HDL-C) ratio for predicting coronary heart disease(CHD) in Korean people. Methods: It was analyzed this data of 5,431 adults who had undergone health examinations in a hospital in Gyeonggi-do between January 2006 and December 2007. The covariation of the coronary risk factors such as age, HbA1C, systolic blood pressure(SBP), and waist-to-stature ratio(WSR) were analyzed by using logistic regression analysis. Results: The LDL : HDL-C ratio in the male and female groups was mostly distributed between 1.5 and 4.0. The LDL : HDL-C ratio was the most significant cholesterol-related parameter influencing CHD (male: B = .306, p = .054, female : B = .940, p = .010), followed by LDL-C and total cholesterol. It was observed a sharp increase in the odds ratios for LDL : HDL-C ratios of 2.25 - 2.50(male) and 2.00 - 2.25(female). A significant difference was observed in both male(2.25 : $x^2$ = 2.494, p = .072) and female(2.00 : $x^2$ = 413.742, p = .000) groups. Conclusion: The risk level of CHD was set to 2.25 for males and 2.00 for females. Therefore, the optimum LDL : HDL-C ratio for Koreans should be far lower than that for the people in western countries.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.362-368
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• 2008

Purpose: It is well known that lung to heart ratio (LHR) is one of the high risk findings in TI- 201 myocardial perfusion SPECT. We evaluated the clinical efficacy of LHR to identify severe coronary artery disease in adenosine stress Tc-99m tetrofosmin gated myocardial perfusion SPECT (gSPECT). Materials and Methods: The study population was 157 patients who underwent both adenosine stress Tc-99m gSPECT and coronary angiography (CAG) within one month. According to the results of CAG and gSPECT LHR and the incidence of increased LHR were compared. Results: Among 53 patients with normal coronary arteries increased LHR was found in 2 patients (3.8%) and 0 in 44 patients (0%) with one vessel disease, 2 in 27 with two vessel disease (7.4%) and 8 in 33 with triple vessel disease (24.2%). Significant differences were found in LHR between subgroups of summed stress score, summed rest score and LV ejection fraction (LVEF). There were weak negative correlation between LHR and LVEF and weak positive correlation between LHR and SSS and SRS. Conclusion: Increased LHR had higher incidence in patients with triple vessel disease, severe LV dysfunction and/or extensive perfusion defect than those of normal group. Although its sensitivity might be low to identify severe coronary artery disease, LHR could be helpful in abnormal myocardial perfusion SPECT to stratify risk and prognosis.

• Journal of Biomedical Engineering Research
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• v.40 no.2
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• pp.62-67
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• 2019

The purpose of this study was to evaluate the performance of deep neural network model in order to determine whether there is a risk factor for coronary artery disease based on the cardiac variation parameter. The study used unidentifiable 297 data to evaluate the performance of the model. Input data consists of heart rate parameters, which are SDNN (standard deviation of the N-N intervals), PSI (physical stress index), TP (total power), VLF (very low frequency), LF (low frequency), HF (high frequency), RMSSD (root mean square of successive difference) APEN (approximate entropy) and SRD (successive R-R interval difference), the age group and sex. Output data are divided into normal and patient groups, and the patient group consists of those diagnosed with diabetes, high blood pressure, and hyperlipidemia among the various risk factors that can cause coronary artery disease. Based on this, a binary classification model was applied using Deep Neural Network of deep learning techniques to classify normal and patient groups efficiently. To evaluate the effectiveness of the model used in this study, Kernel SVM (support vector machine), one of the classification models in machine learning, was compared and evaluated using same data. The results showed that the accuracy of the proposed deep neural network was train set 91.79% and test set 85.56% and the specificity was 87.04% and the sensitivity was 83.33% from the point of diagnosis. These results suggest that deep learning is more efficient when classifying these medical data because the train set accuracy in the deep neural network was 7.73% higher than the comparative model Kernel SVM.

• Journal of Korean Public Health Nursing
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• v.29 no.3
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• pp.540-550
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• 2015

Purpose: The purpose of this study was to examine a combined influence of obesity and metabolic syndrome on ischemic heart disease in Korean middle aged and older adults. Methods: This study used secondary data from the 2013 Korea National Health and Nutrition Examination Survey. A total of 3,726 adults over age 40 were included. Logistic regression was used for analysis of complex samples. Gender, age, educational level, family income, family history of ischemic heart disease, physical activity, smoking, and heavy alcohol consumption were analyzed as covariates. Results: Ischemic heart disease was more prevalent among adults with metabolic syndrome regardless of obesity (non-obesity: Adjusted Odds Ratio [AOR]: 3.044, 95% Confidence Interval [CI]: 1.163-7.967, overweight: AOR: 2.805, 95% CI: 1.246-6.316, obese: AOR: 3.137, 95% CI: 1.548-6.358) compared to the reference group, defined as adults with non-obesity and non-metabolic syndrome. Odds of ischemic heart disease were not significant in the group with obesity and non-metabolic syndrome compared to the reference group. Conclusion: The results of this study show that the population with metabolic syndrome is an at-risk group for ischemic heart disease. Thus, management of metabolic syndrome is required for prevention of ischemic heart disease.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.619-625
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• 2006

Background: Peripheral arterial disease is frequently accompanied with systemic arteriosclerosis and more than half of the cause of deaths is due to the development of coronary arterial disease. Moreover, it is known that the most frequent cause of death after a bypass surgery of chronic arterial obstruction is heart related complications. Especially in patients with atherosclerotic arterial obstruction in the lower extremities who had no history of heart disease or had no presenting symptoms of ischemic heart disease showed a high rate of postoperative mortality and for this reason we suggest preoperative evaluation in these patients to evaluate whether or not coronary arterial disease is accompanied. Material and Method: Since Feb. 2001 to Oct. 2004, we analyzed 52 patients who were operated on for atherosclerotic arterial obstruction in the lower extremities, with the exception of patients with a past history of heart disease or symptoms of ischemic heart disease. They underwent on the same day a coronary and femoral angiography for evaluation of accompanying coronary arterial disease. Of among these patients, we compared those who received bypass surgery of the arteries of the peripheral extremities alone to those who underwent combined coronary artery bypass surgery. Result: 63% of the reported cases of atherosclerotic arterial obstruction in the lower extremities were accompanied with coronary arterial disease. Old age, hypertension, diabetes mellitus, smoking, and hypercholesterolemia are known risk factors for arteriosclerosis and of these, only old age and hypertension had statistically significance in patients with severe atherosclerotic arterial obstruction in the lower extremities accompanied with coronary arterial disease. Diabetes, smoking, and hypercholesterolemia showed no statistical significance in this group. With the increase in severity of the range and the degree of atherosclerotic arterial obstruction, coronary arterial disease is frequently accompanied and its severity also increased. Patients who received both peripheral artery and coronary artery bypass surgery showed no difference in the period of hospitalization and ICU stay period compared with patients who received bypass surgery of the arteries of the lower extremities alone. Conclusion: Patients with atherosclerotic arterial obstruction in the lower extremities without symptoms of ischem to evaluate coronary arterial disease for active treatment, especially in the patients with old age, hypertension and high AVD scores.

• Korean Journal of Community Nutrition
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• v.10 no.6
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• pp.963-970
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• 2005

Recently elevated plasma homocysteine concentration is considered an independent risk factor for atherosclerosis and thrombosis with coronary artery disease. Folate and vitamin $B_{12}$ are cofactors and closely related with metabolism of homocysteine. The purpose of this study is to evaluate the correlation between homocysteine and folate and vitamin $B_{12}$ in patients with ischemic heart disease. Twenty-six patients, in whom coronary angiographic finding revealed more than $50\%$ of stenosis at least in one coronary vessel were enrolled as the patient group, and thirty subjects, in whom angiographic finding revealed in not significant stenosis, but complained of chest pain, were selected as the control group. Fasting venous blood was obtained and measured the concentration of plasma total homocysteine, folate and vitamin $B_{12}$ by high performance liquid chromatography and fluorescence detection method. We examined the correlation between homocysteine and folate and/or vitamin $B_{12}$ in the control group and the patient group, respectively. Compared with the control group, the patient group had relatively higher plasma total homocysteine concentration ($10.7\pm4.2\;vs\;9.6\pm3.5$ umol/L), but showed no significant difference. Folate and vitamin $B_{12}$ concentration are low in the patient group, but showed no significant difference between patient and control group. Plasma total homocysteine concentration showed negative correlation with folate and vitamin $B_{12}$ in both the control group and the patient group, and showed significantly negative correlation in patient group {r = -0.550 (p < 0.01) vs r = -0.609 (p < 0.01)}. We knew that the plasma total homocysteine concentration were relatively elevated in patient group compared with the control group. Because plasma total homocysteine concentrations are closely negative correlated with folate and vitamin $B_{12}$ in the patient group, folate and vitamin $B_{12}$ supplement can lower the mortality and morbidity of ischemic heart disease. (Korean J Community Nutrition 10(6) : $963\∼970$, 2005)

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.65-70
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• 1993

Among 64 patients with acute myocardial infarction who underwent coronary angiogrphy, 7 patients (10.9%) showed normal coronary artery. Six patients were men and 1 patient was female. The mean age of patients were $31.1{\pm}3.9$ years. Among the risk factors of coronary heart disease, smoking was most probable factor in patients with acute myocardial infarction with normal coronary angiography. $^{99m}Tc$-MIBI heart SPECT performed 5 of 7 patients and showed that it could be used in diagnosis, localization, extent of infarct area in patients with acute myocardial infarction with normal coronary angiograpy. But follow up $^{99m}Tc$-MIBI heart SPECT study will be needed to define the ability of myocardial viability in this patients.

• Journal of Preventive Medicine and Public Health
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• v.45 no.5
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• pp.323-328
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• 2012

Objectives: Economic growth and development of medical technology help to improve the average life expectancy, but the western diet and rapid conversions to poor lifestyles lead an increasing risk of major chronic diseases. Coronary heart disease mortality in Korea has been on the increase, while showing a steady decline in the other industrialized countries. An age-period-cohort analysis can help understand the trends in mortality and predict the near future. Methods: We analyzed the time trends of ischemic heart disease mortality, which is on the increase, from 1985 to 2009 using an age-period-cohort model to characterize the effects of ischemic heart disease on changes in the mortality rate over time. Results: All three effects on total ischemic heart disease mortality were statistically significant. Regarding the period effect, the mortality rate was decreased slightly in 2000 to 2004, after it had continuously increased since the late 1980s that trend was similar in both sexes. The expected age effect was noticeable, starting from the mid-60's. In addition, the age effect in women was more remarkable than that in men. Women born from the early 1900s to 1925 observed an increase in ischemic heart mortality. That cohort effect showed significance only in women. Conclusions: The future cohort effect might have a lasting impact on the risk of ischemic heart disease in women with the increasing elderly population, and a national prevention policy is need to establish management of high risk by considering the age-period-cohort effect.