• Journal of radiological science and technology
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• v.37 no.2
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• pp.109-116
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• 2014

Many studies have suggested that in the era of Drug-Eluting Stents(DES) are one of the causes of In-Stent Restenosis(ISR) of Stent Fracture(SF). The present study sought to evaluate clinical characteristics of patients with stent fracture after successful DES implantation. The 4,701 patients were selected for analysis who underwent a follow-up coronary angiography irrespective of ischemic symptoms. The overall incidence of SF was 32 patients(male:female=19:13, Av. age $62.44{\pm}9.8$year, 0.68%). Fractures of Sirolimus-Eluting Stents(SES), Paclitaxel-Eluting Stents(PES), Biolimus A9-Eluting Stents(BES), Everolimus-Eluting Etents(EES), Endothelial Progenitor Cell Capture Stent(EPC) and Zotarolimus-Eluting Stents(ZES) are accounted for 19(59.4%), 9(28.1%), 2(6.3%), 1(3.1%), 1(3.1%) and 0(0%) respectively. SF developed in the left Anterior Dscending(LAD) artery in 16 patients(50%) and in complex(type B2, C) lesions in 25 patients(69.4%). Ten patients were treated with heterogenous DES, the rest being treated with either homogenous DES(3 patients), plain old balloon angioplasty(3 patients), or conservative medical treatment(17 patients). None of the patients with SF suffered from cardiac death during a follow-up period of $32.9{\pm}12.4$ months. The overall rate of DES fracture over up to 3.7 years of follow-up was 0.68% with higher incidence in SES than in PES. SF frequently occurred in the LAD artery and in complex lesions. Of the patients with SF, coronary intervention was performed only when the binary restenosis lesion was significant. During the follow-up, patients with SF have continued on combination antiplatelet therapy. There is a very low rate of major adverse cardiac events(post-detection of SF), especially cardiac death associated with SF.

• Journal of Chest Surgery
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• v.39 no.12 s.269
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• pp.891-899
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• 2006

Background: This study is to evaluate the safety of ATS valve by examining the clinical results of ten-years experience. Material and Method: From July 1995 to March 2005, we reviewed 305 patients with ATS valve implantation. Mean age was $49.8{\pm}11.7$ years and 140(45.6%) males were included. Etiologies were rheumatic diseases in 207 cases(67.4%), degenerative changes in 57 cases(18.6%), valve dysfunction in 23 cases(7.5%) and infective endocarditis in 14 cases(4.6%). AVR was performed in 72 patients(23.5%), MVR in 156 patients (50.8%), DVR(AVR+MVR) in 63 patients(20.5%) and TVR in 16 patients(5.2%). Result: There were 9 operative mortalities(2.9%). Follow up period was $56.5{\pm}34.0(0{\sim}115)$ months and 96.4% patients were followed up with 9 late deaths. Five and ten years survival rates were $94.9{\pm}1.3%,\;91.2{\pm}2.3%$ using Kaplan-Meier's methods. Valve related event free survival rates in 5 and 10 years were $90.8{\pm}2.0%$ and $86.9{\pm}3.2%$. There were 16 anticoagulation-related hemorrhages, 6 thromboembolisms, 3 prosthetic valve endocarditis and 1 paravalvular leakage. NYHA class improved after operation(p<0.05). Postoperative echocardiography showed significant decrease in LA size, LVEDD and IVESD(p<0.01). Patients with 19 and 21 mm valve showed significantly higher transvalvular pressure gradient in aortic position(p<0.001, p<0.001). Conclusion: ATS valve showed good hemodynamic results with few valve related complications and thus can be used with acceptable risk.

• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.5-10
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• 2012

There is a still unsettled issue about the comparison of long-term clinical effects between sirolimus-(SES) and paclitaxel-eluting stents (PES) for the patients with acute myocardial infarction (AMI). Therefore, we performed a retrospective analysis to evaluate the 4-year clinical outcome of SES as compared with PES after percutaneous coronary intervention (PCI) in patients with AMI. From January 2004 to August 2006, all consecutive patients with acute ST-segment elevation myocardial infarction (STEMI) underwent primary PCI and acute NSTEMI underwent PCI by implantation either SES or PES were enrolled. The occurrence of death, cardiac death, recurrent infarction, target vessel revascularization (TVR) and stent thrombosis were analyzed. The composite of major adverse cardiac events (MACE; death, recurrent infarction and TVR) were also analyzed. During the study period, total 668 AMI patients had visited. Of them, total 522 patients (299 with SES and 223 with PES) were enrolled. During 4-year clinical follow-up, there were similar occurrences of death ($18.3{\pm}3.0%$ vs. $14.6{\pm}2.2%$, p=0.26), cardiac death ($11.2{\pm}2.6%$ vs. $6.8{\pm}1.52%$, p=0.39), re-infarction ($6.4{\pm}1.8%$ vs. $3.3{\pm}1.1%$, p=0.31), and stent thrombosis ($5.4{\pm}1.7%$ vs. $3.2{\pm}1.1%$, p=0.53) between the two groups, consecutively. The occurrences of TVR ($10.0{\pm}3.0%$ vs. $4.0{\pm}1.2%$, p=0.008) and MACE ($29.4{\pm}3.5%$ vs. $19.4{\pm}2.5%$, p=0.003) were significantly higher in patients treated with PES than SES. In AMI patients treated with either SES or PES implantation, SES had a significantly lower risk of TVR and MACE during 4-year clinical follow-up. Rates of death, cardiac death or recurrent infarction, and stent thrombosis were similar.

• Journal of Preventive Medicine and Public Health
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• v.34 no.2
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• pp.109-118
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• 2001

The purpose of this review is to discuss the debate concerning the interpretation of epidemiologic studies on particles and health effects. Study of the 1952 air pollution disaster in London established that very high levels of particulate-based smog can cause dramatic increases in daily mortality. However, recent epidemiologic studies have reported statistically significant health effects and mortality due to low levels of air pollution. The statistical significance does not prove causation in observational studies; therefore it is necessary to evaluate these associations. There are arguments for and against each of the numerous studies using Hill's criteria, however the body of accepted evidence supports the causal association. In particular, a high level of consistency in the estimated effect of PM10 has been observed across studies worldwide. The mechanism of the relationship between air pollution and health effects is not obvious. The mechanism of particle-induced injury may involve the production of an inflammatory response by the particulate. The harvesting and the threshold effect are also major concerns regarding the health effects of air pollution. However, current epidemiologic findings indicate that linear models lacking a threshold are appropriate for assessing the effect of particulate air pollution on daily mortality even at current levels.

• Journal of Chest Surgery
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• v.39 no.2 s.259
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• pp.117-126
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• 2006

Background: The purpose of this study is to describe the characteristics of malpractice claims related to hemopneumothorax and to identify the causes and potential preventability of such claims. Material and Method: A retrospective study was performed by reviewing the records in the Lawnb website and Lx CD-rom: the records on closed malpractice claims involving hemopneumothorax were abstracted from the files available for analysis. The records were reviewed and were analysed to determine the etiology of hemopneumothorax, patient age, results of lawsuit and indemnity payment, underlying diseases, cause of death or complications, and the factors associated with a successful defense. Result: Seven closed claim involving hemopneumothorax were founded in the data for malpractice. Three claims were supreme court decision, one was a high court decision and three claims were district court decision. The most common cause of death was tension pneumothorax. Four of which resulted in indemnity payments. Conclusion: While malpractice claims involving hemopneumothorax were uncommon, they resulted in a high rate and amount of indemnity payments. Claims are more common in pediatric patients. In case of iatrogenic hemopneumothorax, post-procedural X-ray can improve patient outcome and is also associated with decreased indemnity risks. Informed consent is also important.

• Journal of Internet Computing and Services
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• v.13 no.4
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• pp.23-31
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• 2012

Nowadays, recognizing human activities is an important subject; it is exploited widely and applied to many fields in real-life, especially in health care and context aware application. Research achievements are mainly focused on activities of daily living which are useful for suggesting advises to health care applications. Falling event is one of the biggest risks to the health and well-being of the elderly especially in independent living because falling accidents may be caused from heart attack. Recognizing this activity still remains in difficult research area. Many systems equipped wearable sensors have been proposed but they are not useful if users forget to wear the clothes or lack ability to adapt themselves to mobile systems without specific wearable sensors. In this paper, we develop a novel method based on analyzing the change of acceleration, orientation when the fall occurs and measure their similarity to featured fall patterns. In this study, we recruit five volunteers in our experiment including various fall categories. The results are effective for recognizing fall activity. Our system is implemented on G1 smart phone which are already plugged accelerometer and orientation sensors. The popular phone is used to get data from accelerometer and results showthe feasibility of our method and significant contribution to fall detection.

• The Korean Journal of Blood Transfusion
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• v.29 no.3
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• pp.229-239
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• 2018

The circulatory system is closely related to the inter-relationship between the anatomy of the heart and blood vessels, and the fluid dynamic properties of blood. The physical properties of blood, which affect blood flow, are called hemorheologic factors. Hemorheologic factors, such as blood viscosity and erythrocyte aggregation, are influenced mainly by hematocrit. A higher hematocrit level results in an increase in blood viscosity, erythrocyte aggregation, which impedes the circulation itself, and tissue oxygenation. An excess of serum ferritin causes injury to vascular endothelial cells and erythrocytes via oxygen free radicals. In addition, an excess of blood can aggravatee the adverse effects of the hemorheologic parameters and induce atherogenesis, microcirculatory disturbances, and major cardiovascular events. A preventive and therapeutic approach with a phlebotomy or blood donation has been stimulated by the knowledge that blood loss, such as regular donations, is associated with significant decreases in key hemorheologic variables, including blood viscosity, erythrocyte aggregation, hematocrit, and fibrinogen. Major cardiovascular events have been improved in regular blood donors by improving blood flow and microcirculation by decreasing the level of oxidative stress, improving the hemorheologic parameters, and reducing the serum ferritin level. Confirmation of the positive preventive and therapeutic effects of blood donations on cardiovascular disease by a well-designed and well-controlled Cohort study may be good news to patients with cardiovascular disease or at risk of these diseases, as well as patients who require a transfusion.

• Journal of The Korean Association For Science Education
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• v.26 no.6
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• pp.753-764
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• 2006

The concept of blood circulation is so complex, dynamic and abstract that students have difficulty in understanding it and students' preconceptions hardly change into scientific concepts even after the lessons. The purpose of this study is to examine middle school, high school, and undergraduate students' understanding of blood circulation and to find the reason why the lack of deep understanding is displayed in students' explanations for the blood circulation. The study consists of three parts. First, the test was designed to investigate students' ideas for blood circulation as components of the structure, the function, the behavior and the mechanism. Second, the test was applied to 7th, 10th and 13th graders to investigate the students' understanding of blood circulation and categorize the types of students' blood circulation model according to their academic level. Finally, the concepts the students had little understanding of were analyzed to decide which ontological category they fell into and further to inquire the characteristics of each concept. The results showed that many students comprehend the structure and the function of blood circulation components well, and there was no significant difference in students' understanding according to the academic level. In contrast, understanding the behavior and the mechanism of circulatory components has remarkably improved in high school students and undergraduates majoring in science and engineering. Also, students' blood circulation models were classified into seven different types. High school students and undergraduates majoring in science and engineering demonstrated a significantly higher percentage on the type of double-loop-branch compared to other academic levels. In addition, it was found that the lack of deep understanding was caused by students' misconceiving the 'equilibrium' category as 'event' category.

• Journal of Chest Surgery
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• v.35 no.11
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• pp.779-784
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• 2002

Recently, the number of coronary artery bypass surgery(CABG) is increasing according to the increasing incidence of coronary artery disease. However, CABG is not a definite corrective surgery; therefore, in some patients, redo-CABG may be required. We retrospectively reviewed our redo-CABG experiences to help future redo-CABG. Material and Method: From January 1991 to April 2001, 14 cases of redo-CABG were performed in Yonsei Cardiovascular Center(M:F＝12:2) and mean age was 61,7 $\pm$ 7.1(47-72) years. Mean time from 1st. CABG to redo-CABG was 121.9 $\pm$ 50.5(6.1-179.6) months. Thirteen cases were conventional on-pump CABG and one case was off-pump CABG. In two patients, mitral valve re-replacement and mitral valve repair were performed each. All redo-CABG were performed through mid-sternotomy. During redo-CABG, left internal mammary artery and saphenous vein grafts were used in 6 patients, left internal mammary artery and left radial artery grafts were used in 2 patients, left internal mammary artery and gastroepiploic artery were used in one patient and only greater saphenous veins were used in 5 cases(In one case, cephalic vein was also used). The number of mean distal anastomosis was 2.1 $\pm$ 0.9(1-4). Result: There were no operative death and no perioperative myocardial infarctions and cerebrovascular accidents or other heart related complications. Mean follow up duration was 40.1 $\pm$ 38.6(1.1-118.5) months. During follow up period, angina was re-developed in one patient 13 months after operation. Two patients died of end-stage renal failure 14.8 months and 116.3 months after redo-CABG, respectively. During follow up period, coronary angiography was performed in 3 patients, and all grafts were patent. At last follow up, mean Canadian class was 1.3. Kaplan-Meier survival at 9 years was 90.0 $\pm$ 9.5% and event free survival at 9 years was 71.4 $\pm$ 6.9%. Conclusion: After redo-CABG, all patients improved their angina symptom and daily activity. And long-term survival after redo-CABG was excellent. Therefore, if patients have indications for redo-CABG, thenredo-CABG must be strongly recommended and performed.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.67-72
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• 2010

Purpose: In Asan Medical Center we perform myocardial perfusion SPECT to evaluate cardiac event risk level for non-cardiac surgery patients. In case of patients with cancer, we check tumor metastasis using whole body bone scan and whole body PET scan and then perform myocardial perfusion SPECT to reduce unnecessary exam. In case of short term in patients, we perform $^{201}Tl$ myocardial perfusion SPECT after whole body bone scan a minimum 16 hours in order to reduce hospitalization period but it is still the actual condition in which the evaluation about the affect of the crosstalk contamination due to the each other dissimilar isotope administration doesn't properly realize. So in our experiments, we try to evaluate crosstalk contamination influence on $^{201}Tl$ myocardial perfusion SPECT using anthropomorphic torso phantom and patient's data. Materials and Methods: From 2009 August to September, we analyzed 87 patients with $^{201}Tl$ myocardial perfusion SPECT. According to $^{201}Tl$ myocardial perfusion SPECT yesterday whole body bone scan possibility of carrying out, a patient was classified. The image data are obtained by using the dual energy window in $^{201}Tl$ myocardial perfusion SPECT. We analyzed $^{201}Tl$ and $^{99m}Tc$ counts ratio in each patients groups obtained image data. We utilized anthropomorphic torso phantom in our experiment and administrated $^{201}Tl$ 14.8 MBq (0.4 mCi) at myocardium and $^{99m}Tc$ 44.4 MBq (1.2 mCi) at extracardiac region. We obtained image by $^{201}Tl$ myocardial perfusion SPECT without gate method application and analyzed spatial resolution using Xeleris ver 2.0551. Results: In case of $^{201}Tl$ window and the counts rate comparison result yesterday whole body bone scan of being counted in $^{99m}Tc$ window, the difference in which a rate to 24 hours exponential-functionally notes in 1:0.114 with Ventri (GE Healthcare, Wisconsin, USA), 1:0.249 after the bone tracer injection in 12 hours in 1:0.411 with 1:0.79 with Infinia (GE healthcare, Wisconsin, USA) according to a reduction a time-out was shown (Ventri p=0.001, Infinia p=0.001). Moreover, the rate of the case in which it doesn't perform the whole body bone scan showed up as the average 1:$0.067{\pm}0.6$ of Ventri, and 1:$0.063{\pm}0.7$ of Infinia. According to the phantom after experiment spatial resolution measurement result, and an addition or no and time-out of $^{99m}Tc$ administrated, it doesn't note any change of FWHM (p=0.134). Conclusion: Through the experiments using anthropomorphic torso phantom and patients data, we found that $^{201}Tl$ myocardium perfusion SPECT image later carried out after the bone tracer injection with 16 hours this confirmed that it doesn't receive notable influence in spatial resolution by $^{99m}Tc$. But this investigation is only aimed to image quality, so it needs more investigation in patient's radiation dose and exam accuracy and precision. The exact guideline presentation about the exam interval should be made of the validation test which is exact and in which it is standardized about the affect of the crosstalk contamination according to the isotope use in which it is different later on.