• Journal of Biomedical Engineering Research
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• v.23 no.6
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• pp.437-449
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• 2002

Coronary arteries are subjected to very different flow conditions compared to other arteries in systemic blood circulation. We Performed a computational fluid dynamic research to investigate influence of such flow conditions in coronary arteries on development and progress of atherosclerosis in the same. The results showed big differences in the flow field of the coronary artery compared to the abdominal and femoral arteries. The coronary artery showed higher wall shear stresses due to the small vessel diameter. On the other hand, it showed only one vortex distal to the stenosis throat during a whole pulse cycle. However. several vortices were observed in the abdominal and femoral arteries in both proximal and distal sides of the stenosis throat The wall shear stresses and extent of recirculation area were increased with impedance phase angle increasing toward more negative values. Therefore, cardiac contraction and the negative impedance phase angle as large as -110。 may induce a flow field that accelerates atherosclerosis.

• Korean Circulation Journal
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• v.48 no.12
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• pp.1120-1130
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• 2018

Background and Objectives: Feasibility of coronary angiography (CAG) and percutaneous coronary intervention (PCI) via left snuffbox approach is still concerned. We aimed to investigate efficacy and safety of the left snuffbox approach for CAG and PCI. Methods: Left snuffbox approach was tried in 150 patients who planned to perform CAG or PCI for suspected myocardial ischemia between 1 November 2017 and 31 March 2018. Results: Success rate of radial artery (RA) cannulation via snuffbox approach was 88.0% (n=132). Among 132 individuals, 58 (43.9%) acute coronary syndrome (ACS) patients were included. The diameter of snuffbox RA was significantly smaller than conventional RA (2.57 mm vs. 2.72 mm, p<0.001) from quantitative computed angiography of 101 patients. However, CAG via snuffbox approach by 6 French sheath was successfully performed in all 132 patients. In addition, there was significant correlation between the snuffbox and conventional RA diameter (r=0.856, p<0.001). In 42 PCI cases, including 25 patients with acute myocardial infarction (AMI), the success rate of PCI via snuffbox approach was 97.6% (n=41). Intravascular imaging-guided PCI was performed in 8 (19.5%) patients and multi-vessel PCI in 4 (9.8%) cases. Regarding vascular complication, forearm swelling with bruising, not requiring surgery or transfusion, occurred in 2 (4.9%) PCI cases. Conclusions: Left snuffbox approach is suitable for CAG and PCI compared with the conventional radial approach.

• 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.

• Clinical and Experimental Pediatrics
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• v.56 no.11
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• pp.500-504
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• 2013

Here we present the case of an 11-year-old female patient diagnosed with Caroli syndrome, who had refractory esophageal varices. The patient had a history of recurrent bleeding from esophageal varices, which was treated with endoscopic variceal ligation thrice over a period of 2 years. However, the bleeding was not controlled. When the patient finally visited the Emergency Department, the hemoglobin level was 4.4 g/dL. Transhepatic intrajugular portosystemic shunt was unsuccessful. Subsequently, the patient underwent percutaneous transhepatic variceal obliteration. Twenty hours after this procedure, the patient complained of aphasia, dizziness, headache, and general weakness. Six hours later, the patient became drowsy and unresponsive to painful stimuli. Lipiodol particles used to embolize the coronary and posterior gastric veins might have passed into the systemic arterial circulation, and they were found to be lodged in the brain, kidney, lung, and stomach. There was no abnormality of the portal vein on portal venography, and blood flow to the azygos vein through the paravertebral and hemiazygos systems was found to drain to the systemic circulation on coronary venography. Contrast echocardiography showed no pulmonary arteriovenous fistula. Symptoms improved with conservative management, and the esophageal varices were found to have improved on esophagogastroduodenoscopy.

• Biomedical Science Letters
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• v.7 no.1
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• pp.7-15
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• 2001

Although extracorporeal circulation (ECC) has been routinely used for cardiovascular surgery, hyperoxemia during ECC may produce oxygen toxicity and cellular injury. This study was performed to investigate the clinical influences of hyperoxemic ECC during cardiovascular operation. 40 adult patients scheduled for elective cardiovascular surgery were classified into normoxemic (arterial oxygen tension: 115 mmHg, n＝20) and hyperoxemic (arterial oxygen tension: 380 mmHg, n＝20) ECC. At preoperative and postoperative period, total leukocyte and neutrophil counts, platelet counts, iron, glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine in peripheral arterial blood, malondialdehyde (MDA) and troponin-T concentration (TnT) in coronary sinus blood, pulmonary vascular resistance (PVR), and postoperative blood loss volume (BLS) were measured and compared between groups. Hyperoxemic group had postoperatively higher total leukocyte and neutrophil counts, MDA, TnT, PVR total BLS, iron, glucose, AST, ALT, BUN, and creatinine than normoxemic group (p<0.05).0 conclusion, hyperoxemic ECC results in greater inflammatory response and oxidative damaging effects on the heart lung, liver and kidney, probably being adverse to postoperative patient recovery. For reducing these deleterious effects and improving postoperative outcomes, management lowering oxygen tension during ECC is recommended.

• Journal of Mechanical Science and Technology
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• v.19 no.5
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• pp.1158-1168
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• 2005

A shunt from the left ventricle to the left anterior descending artery is being developed for coronary artery occlusive disease, in which the shunt or conduit connects the the left ventricle (LV) with the diseased artery directly at a point distal to the obstruction. To aid in assessing and optimizing its benefit, a computational model of the cardiovascular system was developed and used to explore various design conditions. Computational fluid dynamic analysis for the shunt hemodynamics was also done using a commercial finite element package. Simulation results indicate that in complete left anterior descending artery (LAD) occlusion, flow can be returned to approximately 65% of normal, if the conduit resistance is equal for forward and reverse flow. The net coronary flow can increase to 80% when the backflow resistance is infinite. The increases in flow rate produced by asymmetric flow resistance are enhanced considerably for a partial LAD obstruction, since the primary effect of resistance asymmetry is to prevent leakage back into the ventricle during diastole. Increased arterial compliance has little effect on net flow with a symmetric shunt, but considerably augments it when the resistance is asymmetric. The computational results suggest that an LV-LAD conduit will be beneficial when the resistance due to artery stenosis exceeds 27 PRU, if the resistance is symmetric. Fluid dynamic simulations for the shunt flow show that a recirculating region generated near the junction of the coronary artery with the bypass shunt. The secondary flow is induced at the cutting plane perpendicular to the axis direction and it is in the attenuated of coronary artery.

• Journal of Chest Surgery
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• v.12 no.4
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• pp.350-354
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• 1979

The incidence of congenital aortic valvular stenosis has been known rare, and approximately 3-6% of congenital heart diseases. Recently, we experienced 1 case of congenital aortic valvular stenosis, and which was corrected surgically under extracorporeal circulation successfully. A 11 years old male pt. was admitted to N.M.C. because of dyspnea, dizziness, chest pain and episode of syncope. An auscultation, harsh systolic murmur [Gr. IV/VI] was noted at aortic area and also palpable strong thrill. ECG showed LVH c strain pattern and suspicious LVH finding in simple chest P-A film. In Lt. cardiac catheterization, abrupt pressure change [110mmHg] between LV & Aorta was noted across the aortic valve. And aortic insufficiency was absent, well visualized both coronary arteries and suspicious bicuspid aortic valve in aortography. Valve form was bicuspid, large one was noncoronary cusp and another cusp was Rt. & Lt. coronary cusp which was interpositioned rudimentary commissure. Central aortic orifice was about 5ram in diameter. Valvulotomy was done along the fusioned commissure between noncoronary cusp and Rt. & Lt.coronary cusp, and then short incision was added between Rt. coronary cusp & Lt. coronary cusp. Immediate postoperative course smooth but unknown cardiac arrest was noted in POD second day. Complete recovery was done without sequelae by resuscitation. After operation, clinical symptoms were subsided but systolic murmur [Gr. II/VI] was audible at aortic area, diastolic murmur was absent. ECG showed still remained LVH but much decreased R wave voltage in Lt. precordial leads. Simple chest P-A showed no interval changes compared to preop film. Control Lt. heart catheterization revealed still remained pressure gradient [40ramrig] between LV & Aorta. But much decreased pressure gradient compared to preop pressure gradient [110mmHg].

• Journal of Chest Surgery
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• v.25 no.10
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• pp.1048-1054
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• 1992

With use of a simple, inexpensive and nonpharmacological program for blood conservation, 24 consecutive patients underwent elective or urgent coronary artery bypass grafting without need of homologous red cell transfusions and /or fresh frozen plasma transfusions in 16 patients[66.7%]. Left internal mammary artery graftings were done in 18 patients[75%], with supplemental saphenous vein grafts in all. Intraoperatively, autologous heparinized blood was removed before bypass and retransfused at the conclusion of ext-racorporeal circulation. The volume remaining in the oxygenator and tubing set was returned without cell processing or hemofiltration. Using the hard-shell cardiotomy reservoir from the oxygenator, autotransfusion of the shed mediastinal blood was continued hourly by the next early;norning. The mean postoperative mediastinal blood loss was 364$\pm$234ml, whereas 553$\pm$383ml was autotransfused. 4 patients [16.7%] received homologous blood and an additional 4 patients[16.7%] fresh frozen plasma. Thus, in total, 16 patients[66.7%] were not exposed to any homologous blood products during the hospital stay. At discharge, the mean hemoglobin concentration was 10.3$\pm$1.6g /dl. Postoperative complications were few and there was no hospital death.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.1
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• pp.57-64
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• 2018

Major cardiac complication such as acute myocardial infarction can occur unexpectedly in patients without risk factors. We experienced cardiac arrest due to an unexpected acute myocardial infarction in a patient without any risk factors during head and neck reconstructive surgery. The patient was diagnosed with acute myocardial infarction after return of spontaneous circulation. With immediate percutaneous coronary intervention, the patient recovered without complications.

• 순환기질환의공학회:학술대회논문집
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• 2003.11a
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• pp.7-7
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• 2003