• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.52-62
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• 1991

The toxic effect of azalea extract, expecially on cardiovascular system, is relatively unclear. The purpose of this study is to study the possible underlying mechanism and effect of toxic ingredient of azalea on cardiovascular system. The 71 healthy rabbits were divided into 10 groups : In group as preliminary study ; 4cc of normal saline was administered intravenously(N) ; 0.7gm/kg and 1.0gm/kg of azalea extract was administered respectively in the same route, volume(A1, A2) ; atropine was administered intravenously(A) ; after pretreatment with atropine(0.04mg/kg) to block parasympathetic system, azalea extract was injected like the above groups(AA1, AA2) ; normal saline, 0.7gm/kg and 1.0gm/kg of azalea extract were administered respectively with 0.2cc(1 : 1000) epinephrine(E0,E1,E2). We measured the following indices at I minute interval during first 10 minutes and then 10 minute interval during next 30 minutes : RR interval, QTc interval, maximal systolic and diastolic pressure drop with occuring time and presence of significant arrhythmia. The results were as follows : 1. The changes of RR interval, QTc interval were significantly increased in groups by Azalea extract. The blood pressure change was significantly decreased in groups by Azalea extract. There were no significant differences according to dosage of Azalea extract. 2. The changes of RR interval, blood pressure were significant differences between administration of atropine and Azalea extract after pretreatment with atropine, but not in the change of QTc interval. 3. There were no significant differences in the change of RR interval, ATc interval, blood pressure drop according to pretreatment with atropine. 4. The interaction between epineprine and Azalea extract was not noted by the effect of epineprine itself. 5. The ST change by 0.7gm/kg, 1.0gm/kg of Azalea extract was revealed in 1 case(14.0%), 7 case(100%), respectively. 6. Most of all cases with arrhthymia, ventricular tachycardia, ventricular fibrillation, were noted in the group by epineprine, except one case by Azalea extract(1.0gm/kg). It was idioventricular rhythm. In conclusion, azalea extract has negative inotropic and chronotropic effect with arrhythmogenic potential possibly through direct myocardial ischemia or injury but we cann't be absolutely exclusive of actions of autonmic nervous system, especially parasympathetic nervous system.

• Journal of the Korean Society of Radiology
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• v.13 no.6
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• pp.879-887
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• 2019

The purpose of this study is to establish a physiological injection protocol according to body weight, in order to minimize amount of contrast medium and optimize contrast enhancement in pediatric patients performing thoracic CT examinations. The 80 pediatric patients under the age of 10 were studied. Intravenous contrast material containing 300 mgI/ml was used. The group A injected with a capacity of 1.5 times its weight, and groups B, C and D added 5 to 15 ml of normal saline with a 10% decrease in each. The physiologic model which can be calculated by weight about amount of injection of contrast medium and normal saline, flow rate and delay time were applied. To assess image quality, measured average HU value and SNR of superior vena cava, pulmonary artery, ascending and descending aorta, right and left atrium, right and left ventricle. CT numbers of subclavian vein and superior vena cava were compared to identify the effects of reducing artifacts due to normal saline. Comparing SNR according to the contrast medium injection protocol, significant differences were found in superior vena cava and pulmonary artery, descending aorta, right and left ventricle, and CT numbers showed significant differences in all organs. In particular, B group with a 10% decrease in contrast medium and an additional injection of saline showed a low degree of contrast enhancement in groups with a decrease of more than 20%. In addition, the group injected with normal saline greatly reduced contrast enhancement of subclavian vein and superior vena cava, and the beam hardening artifact by contrast medium was significantly attenuated. In conclusion, the application of physiological protocol for injection of contrast medium in pediatric thoracic CT examinations was able to reduce artifacts by contrast medium, prevent unnecessary use of contrast medium and improve the effect of contrast enhancement.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.725-728
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• 2010

Rhabdomyoma is the most common benign cardiac neoplasm in neonates. Most patients with rhabdomyoma experienced spontaneous regression. Yet some of them need surgical therapy because of hemodynamic problems of the heart such as arrhythmia, outflow tract obstruction and valvular dysfunction. We found multiple masses in both ventricles on the patient's fetal echocardiogram. Heart failure caused by severe left ventricular outflow tract obstruction quickly presented after birth. The mass interfering with the outflow tract was resected via the transaortic approach at the first day of birth. Postoperative echocardiography showed complete release of the outflow tract obstruction. He was discharged on the postoperative day 8. During the 3 years of follow up, we found that the sizes of the remnant masses had gradually decreased.

• Journal of Veterinary Clinics
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• v.29 no.3
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• pp.203-206
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• 2012

Treatment for heart failure is directed to reduce atrial volume overload by diuretic agents, to lessen ventricular pressure overload by vasodilatory agents and to increase myocardial performance through inotropic agents. Of those cardiac therapeutics, diuretic agents are the most important to control heart failure in dogs, although long-term use often causes detrimental side-effects such as acute renal failure and electrolyte abnormalities. Thus, this study was designed to find a new diuretic agent from medicinal herbs which has better diuretic effect and less unfavorable complications in dogs. In a preliminary study performed with 5 normal healthy dogs, the extract from Akebia quinata Decaisne showed mild to moderate diuretic effect (0.3-0.5 potency of furosemide 2 mg/kg) and minimal changes in serum chemistry and electrolyte. Although the study population was not large enough and study period was not sufficient enough, this study found a good alternative diuretic agent which can replace or reduce the use of furosemide in dogs with heart failure.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.569-572
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• 2010

A 4-year-old neutered female Pekingese dog (weighing 3.6 kg) was referred with the primary complaint of exercise intolerance with occasional syncope. Physical examination revealed irregularly irregular heart rhythm with persistent pulse deficits. The 12-lead surface ECG showed a marked sinus arrest with occasional junctional escape beats, indicating a sick sinus syndrome. Permanent transvenous cardiac pacing with a rate-responsive bipolar implantable pacemaker (VVIR type) was performed in the right ventricle. After pacemaker implantation, the clinical signs were remarkably improved. No further syncopal episodes have yet been occurred after implantation.

• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.737-744
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• 2005

Purpose : Infants and children with cardiovascular diseases often present with respiratory symptoms. However, missed or delayed evaluation for potential airway problem may complicate overall prognosis. The aim of this study is to determine the clinical characteristics of these patients and explore the cause of airway problem. Methods : We reviewed the medical records of 64 patients(M : F=33:31, mean age : $6.3{\pm}7.5$ months) whose airway problems were proven by computed tomography or bronchoscopy in perioperative periods at the Asan Medical Center from January 1997 to June 2004. Patients were divided into two groups based on the duration of ventilator care : ${\leq}7$ days(group 1 : 23 cases, M : F=10 : 13) and >7 days(group 2 : 41 cases, M : F=23 : 18). Results : The patients in group 2 significantly developed more post-operative respiratory symptoms than group 1(P<0.001) and had more airway problems including extrinsic obstruction, intrinsic anomaly, and combined problem than group 1 although not significantly different(P=0.082). Among underlying diseases, the most common diseases were vascular anomaly(26.2 percent) and aortic arch anomaly(26.2 percent) in group 1 and pulmonary atresia with ventricular septal defect(22.4 percent) in group 2. The most frequent respiratory symptoms were recurrent wheezing pre-operatively and failure of ventilator weaning post-operatively. The major types of airway anomaly were tracheomalacia and tracheal stenosis(in each case 18.2 percent). Nineteen patients with persistent airway problems underwent aortopexy or other vascular correction. Of the 19 patients, 13(68.4 percent) were improved, but 2 failed in weaning ventilator and 4 died of non-airway problems. Conclusion : Early evaluation and treatment for potential airway problems may affect natural or surgical prognosis in patients with cardiovascular diseases presenting with respiratory symptoms.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.822-827
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• 1996

Ross procedure is an ideal operative modality for diseased aortic valve especially in children, but homogrart for right ventricular outflow tract(RVOT) reconstruction is not easily available in Korea. We tried to perform REV procedure for RVOT reconstruction in 10 young piglets(15.3 $\pm$ 1.3 kg) In an attempt to e clude the use of homograft in Ross operation. 3 of them survived after operation and raised till adult pig(about 70 kg), then examined their pulmonary arteries and hearts. Without any stenotic residues in the great arteries, we only found the deformed monocusp patch with severe calcification, which deprived the adequate valve function, but kept the pig growing normally We are sure that this operative modality (REV + Ross procedure) could be extendedly applied to the diseased human aortic valve, but we need to develope the anti-calcification method for the heterograft patch.

• Journal of IKEEE
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• v.5 no.2 s.9
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• pp.182-189
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• 2001

Single-pass VDD pacemakers have been used as a result of simple implantation procedures and generally reliable atrial tracking that ensures an A-V sequence pacing. However, there is a controversy over their reliabilities of atrial tracking. As a new sensing method for reliable atrial tracking, a simple automatic pacemaker sensing algorithm was implemented and evaluated to validate its benefits in sensing depolarization waves of Single-pass VDD atrial electrograms. The automatic sensing algorithm had a predetermined sensing dynamic range and the sensitivity level was controlled as 50% of the average of two most recently sensed intrinsic amplitudes. The behavior of the automatic sensing algorithm in the Single-pass VDD atrial electrograms was analyzed and characterized. It was observed that the automatic sensing algorithm was more effective than a conventional fixed threshold method to accurately detect and track p-waves in Single-pass VDD electrograms.

• Journal of Chest Surgery
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• v.38 no.7 s.252
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• pp.504-506
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• 2005

Intracavitary coronary artery is variant anomalous entrance to right ventricular cavity of left anterior descending artery. Since the disease is extremely rare, there has not been any report of it in Korea and is only found in $0.2\~0.3\%$ of all CABG patients. It is very difficult to be diagnosed by preoperative coronary arteriography (CAG) and secure suture is needed for right ventriculotomy after CABG due to bleeding from right ventricle. Horizontal mattress suture with pledget has been recommended but, it could compress the myocardium surrounding ventriculotomy and result in disturbed flow of left anterior descending artery branch and perforating artery. So we used simple interrupted suture and the patient was recovered as other CABG patients without complications.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1213-1217
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• 2011

Electric stimulators are used for various treatments, such as for pain relief and to improve rehabilitation in and out of the hospital. However, if the stimulation pulse affects the patient's heart, it can cause critical cardiac disorders such as arrhythmia or ventricular fibrillation. As a result, it must be ensured that the transmission length of the stimulation pulse does not exceed the proper range in the design of an electric stimulator. Furthermore, every anticipated risk factor must be monitored in in-vitro and in-vivo experiments. A new stimulator was designed to supply continuous 0.001 J stimulation pulses at a rate of 60 pulses per second. To evaluate the safety of the new electric stimulator and to measure its energy transfer and pulse transmission length, we built a conduction model that was filled with saline and measured the electric field at various positions in response to real stimulations. In an animal experiment with two pigs, heart disorders were induced by applying electric stimulation to tissues near the heart. These heart disorders were different from the result obtained with 9 V DC stimulation.