• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.205-207
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• 1996

Clonidine, an antihypertensive drug, stimulates postsynaptic alpha-2 adrenergic receptors in the central nervous system and lowers arterial pressure through the effects on both cardiac output and peripheral resistance. However, many patients experience that sedation and xerostomia occur upon oral administration of clonidine. These side effects are due to high plasma peak concentration and can be avoided when clonidine is given transdermally. In this study, we tested the antihypertensive effects of trandermal administration of clonidine patch on spontaneously hypertensive rat (SHR) which is a model animal for human essential hypertension. Forty eight SHR (male) were divided into six groups according to the dose levels, respectively. After transdermal administration of clonidine patch of each dose, systolic blood pressure and heart rate were measured. Clonidine patch produced maximal antihypertensive and bradycardiac effects 48 hrs after administration and antihypertensive effects showed dose-dependency. We suggest that antihypertensive effects of clonidine patch are similar to those of orally given clonidine and clonidine patch can be used instead of clonidine tablet.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.202-204
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• 1996

Clonidine, an antihypertensive drug, stimulates postsynaptic $\alpha_2$adrenergic receptors in the CNS and lowers arterial pressure by erects on both cardiac output and peripheral resistance. However, many patients experience that sedation and xerostomia occured upon oral administration of clonidine. These side effects are due to high plasma peak concentration and can be avoided when clonidine is given transdermally. In this study, we performed the skin irritation test for transdermal administration of clonidine patch on New Zealand white rabbits. Twelve New Zealand white rabbits were divided into two groups according to the dose levels, respectively. After transdermal administration of clonidine patch with two doses, clinical manifestations, body weight loss and postmortem findings were observed. We could not find any significant evidence of skin irritation by transdermal administration of clonidine patch.

• Advances in biomechanics and applications
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• v.1 no.2
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• pp.127-141
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• 2014

A preliminary study of a new pulsatile pump that will work to a frequency greater than 1 Hz, is presented. The fluid-structure interaction between a Newtonian blood flow and a piston drive that moves with periodic speed is simulated. The mechanism is of double effect and has four valves, two at the input flow and two at the output flow; the valves are simulated with specified velocity of closing and reopening. The simulation is made with finite elements software named COMSOL Multiphysics 3.3 to resolve the flow in a preliminary planar configuration. The geometry is 2D to determine areas of high speeds and high shear stresses that can cause hemolysis and platelet aggregation. The opening and closing valves are modelled by solid structure interacting with flow, the rhythmic opening and closing are synchronized with the piston harmonic movement. The boundary conditions at the input and output areas are only normal traction with reference pressure. On the other hand, the fluid structure interactions are manifested due to the non-slip boundary conditions over the piston moving surfaces, moving valve contours and fix pump walls. The non-physiologic frequency pulsatile pump, from the viewpoint of fluid flow analysis, is predicted feasible and with characteristic of low hemolysis and low thrombogenesis, because the stress tension and resident time are smaller than the limit and the vortices are destroyed for the periodic flow.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.3
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• pp.96-101
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• 2013

Increased waist circumference has shown to be more strongly associated with cardiovascular disease risk factors. The purpose of this study is to investigate the association between exercise capacity and cardiovascular risk factors among obese types in adult men. The subjects of this study were a total fifty-four obese persons and obesity criteria is body mass index $(BMI){\geq}25kg/m^2$. Diagnostic criteria for obesity was defined as a waist circumference of ${\geq}90cm$. The BMI in the obese subjects, as judged by the presence or absence of abdominal obesity, were classified into two groups (non-AO: without abdominal obesity group, AO: with abdominal obesity group). AO presented lower total exercise time, metabolic equivalents (METs) than Non-AO. AO showed slow HRR (heart rate recovery) response. HRR was negative correlated with BMI, body fat mass, waist circumference. AO had a high heart rate and a low cardiac output in submaximal exercise stage 1~2. In conclusion, AO's (with abdominal obesity groups) total exercise time, METs and HRR are lower than Non-AO. HRR is related with BMI, body fat mass and waist circumference.

• Journal of Chest Surgery
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• v.24 no.2
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• pp.115-122
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• 1991

From April 1986 to December 1989, 25 infants under the age of 12 months with tetralogy of Fallot were operated on. Age ranged from 3 to 12 months[mean 8.9$\pm$4.9 months] and mean body weight was 7.8$\pm$ 2.6kg. All the patients were deeply cyanotic, 12 of them experienced anoxic spell. Transannular patch was laid down in 19 patients, in 7 of them monocuspid patch was utilized. Postrepair P RV/LV was measured at operation room in 17 patients[mean 0.48$\pm$0. 14]. Hospital mortality was 20Yo. Causes of deaths include right ventricular failure and low cardiac output. The mortality was closely related with patient`s age and body surface area at operation. Also higher mortality was noticed in patients having major associated anomaly or previous palliative operation, preoperative management with propranolol and transannular repair. 18 patients were followed up for 12 to 50 months with a mean follow-up time of 24 months after operation. There were no late deaths and late ventricular arrhythmia or congestive heart failure was not detected as yet. Redo operation was performed in one case because of residual pulmonic stenosis. Considering several advantages of early primary repair, primary repair of symptomatic infants with tetralogy of Fallot should be encouraged despite somewhat high mortality rate as yet and better results could be anticipated along with improvement of myocardial protection method and postoperative care.

• Journal of Chest Surgery
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• v.20 no.3
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• pp.536-543
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• 1987

The Fontan procedure was physiological correction which was initially applied to tricuspid atresia. We had used the modified Fontan operation in 8 cases at National Medical Center, Seoul, from Aug. 1984 to Oct. 1986. Age range was 20 months to 15 years [mean: 9 years] and male: female ratio was 5:3. 5 patients had tricuspid atresia [lb: 2 cases, Ic: 1 case, lib: 1 case, & llc: 1 case], 2 Patients had univentricular heart of left ventricular type, and one patient had transposition of great arteries with complete endocardial cushion defect. The operative principle was direct anastomosis between right atrium and pulmonary artery, whether main pulmonary artery or right pulmonary artery without any conduits. Postoperatively all patients needed high central venous pressure for adequate hemodynamic status in both survival [20-24 CmH2O] and mortality groups [20-24 CmH2O]. The fatal complications were as follows: empyema with bronchopleural fistula [1 case], bleeding tendency & brain damage [1 case], low cardiac output syndrome & acute renal failure [2 cases], and right to left shunt of unknown origin [1 case]. There were 5 hospital deaths; 3 of 5 tricuspid atresia patients, 1 of 2 univentricular heart patients, and 1 of 1 transposition of great arteries with complete endocar4ial cushion defect patient. The overall mortality was 62.5%. 3 survivors were nearly compatible with Choussat & Fontan criteria. Thus appropriate patient selection and experienced surgical technique were required for good results.

• Journal of Trauma and Injury
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• v.27 no.4
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• pp.204-207
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• 2014

Non-occlusive mesenteric ischemia (NOMI) encompasses all forms of mesenteric ischemia with patent mesenteric arteries. NOMI is commonly caused by decreased cardiac output resulting in hypoperfusion of peripheral mesenteric arteries. We report a case of NOMI secondary to hemorrhagic shock and rhabdomyolysis due to trauma. A 42-year-old man presented to our trauma center following a pedestrian trauma. On arrival, he was drowsy and in a state of hemorrhagic shock. He was found to have multiple fractures, both lung contusion and urethral rupture. An initial physical examination and abdominal computed tomography (CT) scan revealed no evidence of intra-abdominal injury. High doses of catecholamine were administered for initial 3 days due to unstable vital sign. On day 25 of hospitalization, follow-up abdominal CT scan demonstrated that short segment of small bowel loop was dilated and bowel wall was not enhanced. During exploratory laparotomy, necrosis of the terminal ileum with intact mesentery was detected and ileocecectomy was performed. His postoperative course was uneventful and is under rehabilitation.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.367-370
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• 2014

The study was to observe hemodynamic alterations of cardiac function to design a model of canine mitral valve insufficiency (MVI) based on chordae tendinae rupture (CTR). Ten healthy beagles with normal heart function were used in this study. To measure hemodynamics, the patient monitor was equipped for invasive blood pressure and a Swan-Ganz catheter. Hemodynamic alterations were checked promptly during CTR procedures. MVI model was made by transection of the chordae tendinae with small arthroscopy hook knife through $5^{th}$ intercostal open chest. Color Doppler at the level of the mitral valve showed high-velocity regurgitant flow immediately after CTR at intraoperative echocardiography. In hemodynamic measurements, pulmonary capillary wedge pressure (PCWP) was significantly increased, while mean arterial pressure (MAP), venous pressure (VP), pulmonary arterial pressure (PAP), cardiac output (CO) and cardiac index (CI) were significantly decreased after CTR. It was known that the left atrium was overloaded by regurgitant volume from the left ventricle. In conclusion, the MVI model induced by CTR technique in this study should be used as suitable one for the effective research of canine mitral valve disease. Further study should be needed to measure the chronic alternation of mitral valve in the model.

• Tuberculosis and Respiratory Diseases
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• v.48 no.3
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• pp.347-356
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• 2000

Background : Patients with obstructive sleep apnea syndrome are known to have high long-term mortality compared to healthy subjects because of their cardiovascular dysfunction. The observation of hemodynamic changes by obstructive apneas is helpful when attempting to understand the pathophysiological mechanism of the development of cardiovascular dysfunction in those patients. Therefore, we studied the changes in cardiovascular function with an animal model and tried to obtain the basic data for an ideal experimental model (this phrase is unclear), a requirement for a more advanced study. Methods : Sixteen anesthetized dogs with ${\alpha}$-chloralose delete were divided into two groups : 8 dogs of room air breathing group and 8 dogs of oxygen breathing group. We measured $PaO_2$, $PaCO_2$, heart rate, cardiac output, mean femoral artery pressure, and mean pulmonary artery pressure at specified times during the apnea-breathing cycle before endotracheal tube occlusion (baseline), 25 seconds after endotracheal tube occlusion (apneic period), 10 seconds (early phase of postapneic period, EPA) and 25 seconds (late phase of postapneic period, LPA) after spontaneous breathing. Results : In room air breathing group, the heart rate significantly decreased during the apneic period compared to that at baseline (P<0.01) and increased at EPA and LPA compared to that during the apneic period (P<0.01). But, the heart rate showed no significant changes during apneic and postapneic periods in the oxygen breathing group. Cardiac output tended to decrease during apneic period compared to that at baseline, but was statistically significant. Cardiac output significantly decreased at LP A compared to at baseline (P<0.01). Mean femoral artery pressure was significantly decreased at during apneic period compared to that at baseline (P<0.05). Conclusion : Through this experiment, we were partially able to understand the changes of cardiovascular function indirectly, but delete new experimental animal model displaying physiological mechanism close to natural sleep should be established, and the advanced study in the changes of cardiovascular function and their causes should be continued.

• Journal of the Korean Society of Radiology
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• v.10 no.7
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• pp.511-519
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• 2016

Left ventricular diastolic dysfunction is mostly observed in patients with cardiac disease, such as myocardial ischemia or LVH, but linking is usually observed in healthy people without heart disease. Evaluation of left ventricular diastolic failure in normal cardiac output(systolic function) conditions can affect the progress and prognosis of heart failure. The direct relevance to the epicardial adipose tissue metabolism in cardiovascular engine for generating a bioactive moleculer, which leads to dysfunction of the later had a direct effect on myocardial heart. The purpose of this study is to measure the thickness of the epicardial adipose tissue was to study the relevance of the assessment of diastolic dysfunction in systolic function in normal conditions. Results epicardial adipose tissue thickness and diastolic dysfunction was analyzed to have a high correlation in a statistically significant level. In particular, the epicardial adipose tissue thickness measured at the measuring section EAT2 and diastolic function evaluation E' was found to have a high correlation. Thus epicardial adipose tissue thickness variation is believed can be used as a predictor to evaluate the left ventricular diastolic dysfunction.