• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.199-203
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• 1998

Acute hemodynamic effects of CJ-18513, a non-peptide angiotensin IIreceptor antagonist, were examined in mongrel dogs treated with high frequency ventricular pacing for one week. Rapid ventricular pacing reduced mean blood pressure (mBP), Lvdp/dt and cardiac output (CO), and increased the left ventricular end-diastolic pressure (LVEDP) and pulmonary capillary wedge pressure (PCWP). Continuous infusion of CJ-10513 at doses of 10 and 20$\mu$g/kg/min, respectively, for 30 minutes reduced mBP, LVEDP and myocardial oxygen consumption rate (MVO,) and shifted the cardiac function curve (CO-LVEDP ourve) to the left in this dog model. In conclusion, CJ-10513 decreased the preload and afterload and increased the cardiac function in dogs with pacing-induced heart failure.

• Journal of Chest Surgery
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• v.24 no.11
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• pp.1081-1089
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• 1991

Atrial fibrillation is characterized by beat to beat irregularity of shape, size, conduction time and polarity. The mechanism of atrial fibrillation can be explained by so called "Multiple wavelet theory". The adverse effect of atrial fibrillation is the decrease of cardiac output by absence of atrial kick[10 ~ 15%] and the possibility of thrombosis in the left atrium which is dangerous to develop the thromboembolism is increased. The present study was designed to assess the effect of overdrive pacing on the suppression of recurring of atrial fibrillation after open heart surgery and the results were summarized as follows: 1. There were no significant differences of factors between converting patients and non-converting patients to normal sinus rhythm by electric cardioversion after open heart surgery. 2. Among converting patients to normal sinus rhythm, there were no significant differences of factors between study group and control group. 3. Cardiothoracic Ratio on the preoperative chest film was significantly larger in the patients of recurring atrial fibrillation within 72hrs than in the patients of maintaining normal sinus rhythm. [61.7$\pm$ 1.4% vs 67.7$\pm$2.4%, p=0.03] 4. There was a significant difference of suppressive effects between overdrive pacing group and control group among recurred cases until 24, 48, and 72hours [Fisher`s exact test ; p=0.037, p=0.076, p=0.53, respectively] 5. There was a difference of the delay of recurring of atrial fibrillation between study group and control group among recurred cases within 72 hours.[53.4$\pm$6.9hr vs. 19.3$\pm$3.8 hr, p<0.01] We think that the overdrive pacing may suppress the natural pacemaker and the converted normal sinus rhythm is maintained longer than control group during critical immediate postoperative period.ve period.

• Dementia and Neurocognitive Disorders
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• v.17 no.3
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• pp.90-99
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• 2018

Background and Purpose: To explore anatomic substrate of specific wandering patterns in patients with Alzheimer's disease (AD) by performing positron emission tomography with $^{18}F$ fluorodeoxyglucose positron emission tomography (FDG PET). Methods: Drug-naïve AD patients with wandering (n=80) and without wandering (n=262) were recruited. First, the specific pattern of wandering type was operationally classified according to specific wandering score and clinical assessment. Second, brain FDG PET was performed and fluorodeoxyglucose (FDG) uptake differences of specific brain regions according to wandering patterns were compared to those of non-wanderers. Results: In patients with pacing pattern, FDG PET showed significant lower FDG uptake in both middle cingulum and left putamen cluster compared to non-wanderers. The right precuneus and supplementary motor area in patients with random pattern and left calcarine sulcus, right calcarine sulcus, right middle cingulum, and right post central gyrus in patients with lapping pattern had significantly lower FDG uptake compared to non-wanderers. Conclusions: This study showed that wandering in patients with AD had three distinct patterns. These specific patterns showed significant lower FDG uptake in specific brain areas compared to non-wanderers.

• Journal of Korea Game Society
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• v.21 no.1
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• pp.25-34
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• 2021

The purpose of this study is to develop online gamification contents to prove the social entrepreneurship of adolescents and verify the effectiveness. To implement the Agzak class, a youth social problem-solving education program, via Google spreadsheet for this study. To analyze the effectiveness of the developed contents 1378 middle school students participated in A area for the survey. According to the results, online content is more effective than offline content in understanding social problems and future talents. Based on the results of this study, it suggests further development of sustainable online education contents by gamification.

• Journal of Cardiovascular Imaging
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• v.30 no.1
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• pp.62-75
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• 2022

BACKGROUND: Due to its location very close to the bundle of His, mitral annulus calcification (MAC) might be associated with the development of atrioventricular (AV) conduction disturbances. This study assessed the association between MAC and AV conduction disturbances identified by cardiac implantable electronic device (CIED) use and electrocardiographic parameters. The association between MAC and traditional cardiovascular risk factors was also assessed. METHODS: This cross-sectional study analyzed 14,771 participants, predominantly men aged 60-75 years, from the population-based Danish Cardiovascular Screening trial. Traditional cardiovascular risk factors were obtained. Using cardiac non-contrast computed tomography imaging, MAC scores were measured using the Agatston method and divided into absent versus present and score categories. CIED implantation data were obtained from the Danish Pacemaker and Implantable Cardioverter Defibrillator Register. A 12-lead electrocardiogram was available for 2,107 participants. Associations between MAC scores and AV conduction disturbances were assessed using multivariate regression analyses. RESULTS: MAC was present in 22.4% of the study subjects. Participants with pacemakers for an AV conduction disturbance had significantly higher MAC scores (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.01-1.23) than participants without a CIED, whereas participants with a CIED for other reasons did not. Prolonged QRS-interval was significantly associated with the presence of MAC (OR, 1.45; 95% CI, 1.04-2.04), whereas prolonged PQ-interval was not. Female sex and most traditional cardiovascular risk factors were significantly associated with high MAC scores. CONCLUSIONS: MAC was associated with AV conduction disturbances, which could improve our understanding of the development of AV conduction disturbances.

• Journal of The Korean Society of Clinical Toxicology
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• v.19 no.2
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• pp.133-138
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• 2021

Glufosinate-containing herbicides is a non-selective herbicide commonly used worldwide. As the use of them increased gradually since paraquat was banned in 2012, the number of suicides by their ingestion is also increasing continuously. Complications of glufosinate-containing herbicide poisoning include various central nervous system (CNS) toxicities such as convulsions, loss of consciousness, memory impairment, and respiratory depression, which may be accompanied by hemodynamic changes such as bradycardia and hypotension. However, it is very rare that arrhythmias other than bradycardia occurred and Takotsubo cardiomyopathy was combined due to cardiotoxicity. A 71-year-old female patient was transferred to our hospital after ingesting 500 mL of glufosinate-containing herbicide and receiving 5 L of gastric lavage at a local hospital. A few hours later, she presented stuporous mentality, respiratory depression, and convulsions, and was accompanied by hypotension and bradycardia. On the second day of admission, electrocardiogram (ECG) showed bradycardia and QTc prolongation with hemodynamic Instability. Accordingly, we conducted the early treatment with continuous renal replacement therapy (CRRT) and the application of temporary cardiac pacemaker. An echocardiogram demonstrated decreased ejection fraction (EF) and Takotsubo cardiomyopathy on the third day of admission. Then, she was discharged safely with conservative treatment. At the follow-up after 1 year, Takotsubo cardiomyopathy, EF and QTc prolongation were recovered on echocardiogram and ECG. Because cardiac toxicity after glufosinate-containing herbicide poisoning may cause life-threatening consequences, caution is required while treating the patient. Therefore, if electrocardiogram changes are seen in the elderly with a large amount of glufosinate herbicide ingestion, additional cardiac function test through echocardiography should be concerned, and early treatment through CRRT or artificial cardiac pacing should be considered.

• Korean Circulation Journal
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• v.52 no.12
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• pp.865-875
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• 2022

Background and Objectives: Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure. However, in pediatric and congenital heart disease (CHD) patients, current adult indications cannot be directly applied because of heterogeneity in anatomy and diagnosis. Therefore, CRT responses and clinical outcomes in these patients were investigated to derive possible candidates for CRT. Methods: This study retrospectively analyzed 16 pediatric and CHD patients who underwent CRT implantation at a single center in early (0.7±0.2 year) and late (4.7±0.3 years) follow-up period after CRT. Results: The median age at CRT implantation was 2.5 (0.3-37.2) years, and median follow-up duration was 6.3 (0.1-13.6) years. Thirteen had non-transvenous CRT. Two had congenital complete atrioventricular (AV) block with previous right ventricular pacing, 5 had dilated cardiomyopathy (DCM) with left bundle branch block, and 9 had CHD. The mean ejection fraction of the systemic ventricle increased from 28.1±10.0% to 44.3±21.0% (p=0.003) in early and 51.8±16.3% (p=0.012) in late outcome. The mean functional class improved from 3.1±0.9 to 1.8±1.1 after CRT (p=0.003). Twelve patients (75%) showed improvement in ventricular function or functional class after CRT. Proportion of responders differed between patients without CHD (2/2 patients with complete AV block and 5/5 with DCM, 100%) and those with CHD (5/9, 56%), although statistical significance was not reached (p=0.088). Conclusions: CRT improved ventricular function and functional status according to the underlying condition in pediatric and CHD patients. However, further large and longer-term studies are needed to establish the guideline for the patient selection of CRT in these patients.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.467-473
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• 2004

Background: The sinus conversion rate after the maze procedure in chronic atrial fibrillation using radiofrequency energy is lower than with either conventional 'cut and saw' technique or cryothermia. The creation of incomplete transmural lesions due to poor tissue-catheter contact is thought to be the main cause. To address this problem, the current study was aimed to evaluate the effectiveness of a specially constructed compression device designed to enhance tissue catheter contact during unipolar radiofrequency catheter ablation. Material and Method: Circum-ferential right auricular epicardial lesions were created with a linear radiofrequency catheter in 10 anesthetized pigs. A device specially designed to increase contact by compression of the catheter to the atrial wall was used in 5 pigs (study group). This device was not used in the control group (5 pigs). Conduction block across the right auricular lesion was assessed by pacing, and the transmurality of the lesions were confirmed by microscopic examination. Result: Conduction block was observed in a total of 8 pigs; 5 in study group and 3 in control group. Transmural injury was confirmed microscopically by the accumulation of acute inflammatory cells and loss of elastic fibers in the endocardium. In two pigs with failed conduction block, microscopic examination of the endocardium appeared normal. Conclusion: Failed radiofrequency ablation is strongly related to non-transmural energy delivery. The specially constructed compression device in the current study was successful in creating firm tissue-catheter contact and thereby generating transmural lesions during unipolar radiofrequency ablation.