• Proceedings of the KOSOMBE Conference
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• 대한의용생체공학회 1991년도 추계학술대회
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• pp.142-144
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• 1991

In this study, we have developed 64 channel computerized cardiac mapping system using micro-computer for basic research of electrophysiology and electrical propagation in cardiac arrhythmias. The significant problems of this study are the simultaneous acquisition of large amount data at 64 sites, the need of accurate and rapid analysis, and the effective display of the analyzed data. To solve these problems, we made 64 channel signal pre-processing board in order to amplify and filter the raw signals. And the software for cardiac isochronous mapping which were presented immediately via computer-generated graphics has been developed. This system is expected to enable us to study pathophysiology of cardiac arrhythmia and to improve the results of diagnosis and surgical treatment for cardiac arrhythmia.

• Clinical and Experimental Pediatrics
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• 제58권7호
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• pp.263-266
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• 2015

Purpose: Ventricular repolarization is assessed using the QT interval corrected by the heart rate (QTc) via an electrocardiogram (ECG). Prolonged QTc is associated with an increased risk of arrhythmias and cardiac mortality. As there have been few reports regarding the effects of hyperthyroidism on ventricular repolarization, we studied the association between serum free thyroxine (free T4 [fT4]) and thyroid stimulating hormone (TSH) levels and the QTc interval. Methods: Thirty-eight patients with hyperthyroidism (<30 years old) were included, and we used their clinical records and available ECGs (between August 2003 and August 2011) to evaluate the association between their fT4 and TSH levels and their QTc interval. In addition, we studied the ECGs of 72 age-matched patients with no hyperthyroidism (control group) and compared their data with that from the patients group. Results: The QTc duration in patients with hyperthyroidism was significantly prolonged compared to that in the control subjects (P<0.001). In addition, the number of hyperthyroid patients with abnormal prolonged QTc was significantly higher than that in the control group (P<0.001). Among the patients with hyperthyroidism, patients with prolonged QTc and borderline QTc had higher fT4 levels and there was positive correlation between their fT4 levels and their QTc interval (P<0.05). However, no correlation was observed between their TSH levels and their QTc interval. Conclusion: We report that hyperthyroidism is associated with QTc prolongation. The correlation between the fT4 levels and the QTc interval suggests that thyroid status is associated with QTc values and the risk of cardiac mortality.

• Journal of Chest Surgery
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• 제55권5호
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• pp.364-377
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• 2022

An anatomical understanding of the atrial myocardium is crucial for surgeons and interventionists who treat atrial arrhythmias. We reviewed the anatomy of the inter-nodal and intra-atrial conduction systems. The anterior inter-nodal route (#1) arises from the sinus node and runs through the ventral wall of the atrial chambers. The major branch of route #1 approaches the atrioventricular node from the anterior aspect. Other branches of route #1 are Bachmann's bundle and a vestibular branch around the tricuspid valve. The middle inter-nodal route (#2) begins with a broad span of fibers at the sinus venarum and extends to the superior limbus of the oval fossa. The major branch of route #2 joins with the branch of route #1 at the anterior part of the atrioventricular node. The posterior inter-nodal route (#3) is at the terminal crest and gives rise to many branches at the pectinate muscles of the right atrium and then approaches the posterior atrioventricular node after joining with the vestibular branch of route #1. The branches of the left part of Bachmann's bundle and the branches of the second inter-nodal route form a thin myocardial network at the posterior wall of the left atrium. These anatomical structures could be categorized into major routes and side branches. There are 9 or more anatomical circles in the atrial chambers that could be structural sites for macro re-entry. The implications of normal and abnormal structures of the myocardium for the pathogenesis and treatment of atrial arrhythmias are discussed.

• Proceedings of the Korean Biophysical Society Conference
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.52-52
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• 2003

Junctate is a newly identified integral ER/SR membrane $Ca^{2+}$ binding protein, which is an alternative splicing form of the same gene generating aspartyl $\square$-hydroxylase and junctin. To elucidate the functional role of junctate in heart, transgenic (TG) mice overexpressing mouse cardiac junctate-1 under the control of mouse $\square$$^{~}$ myosin heavy chain promoter were generated. Overexpression of junctate in mouse heart resulted in cardiac hypertrophy, increased fibrosis, bradycardia, arrhythmias and impaired contractility. Overexpression of junctate also led to down-regulation of SERCA2, calsequestrin, calreticulin and RyR, but to up-regulation of NCX and PMCA. The SR $Ca^{2+}$ content decreased and the L-type $Ca^{2+}$ current density and the action potential durations increased in TG cardiomyocytes, which could be the cause for the bradycardia in TG heart. The present work has provided an important example of pathogenesis leading to cardiac hypertrophy and arrhythmia, which was caused by impaired $Ca^{2+}$ handling by overexpression of junctate in heart.n heart.

• Journal of Chest Surgery
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• 제25권1호
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• pp.73-78
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• 1992

From Octorber 1984 through September 1991, 480 patients underwent percutaneous tra-nsluminal coronary angioplasty and 7 of these[1.4%] required coronary artery bypass surgeries in the emergency base. The principal indications for surgery were coronary dis-sections[n=2], acute coronary occlusions[n=3], and ventricular arrhythmias[n=2]. There were two early deaths and one late death. No patient who developed cardiac arrest and had not been resuscitated before surgery survived the operation. The outcome of surgery was related to the preoperative clinical status of patients.

• Proceedings of the Korean Biophysical Society Conference
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• 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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• pp.64-64
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• 1999

Amitriptyline has been known to induce QT prolongation and ventricular arrhythmias such as torsades de pointes which causes sudden death. We studied the effects of amitriptyline on the human ether-a-go-go-related gene (HERG) channel expressed in Xenopus oocytes.(omitted)

• Journal of Chest Surgery
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• 제22권4호
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• pp.580-588
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• 1989

The potential for enhancing myocardial protection by adding high-energy phosphate to cardioplegic solutions [St. Thomas Hospital solution] was investigated in a rat heart model of cardiopulmonary bypass and ischemic arrest. Creatine phosphate was evaluated as an additive to the St. Thomas Hospital cardioplegic solution. Creatine phosphate 10.0 mmol/L as the optimal concentration which improved recovery of aortic flow and cardiac output after a 30 minute period of normothermic [37oC] ischemic arrest. In comparing mechanical function in both groups the mean postischemic recoveries of aortic flow, cardiac output, stroke volume and stroke work [expressed as a percentage of its preischemic control] were significantly greater in STH-CP group than in CP- free control group. In addition to improving function and decreasing CK release, CP reduced reperfusion arrhythmias significantly decreasing the time between cross-clamp removal and return to regular rhythm from 81.8 * 13.9 [sec] in CP-free group to 35.9 * 6.8 [sec] in CP group [P< 0.05] so, exogenous CP exerts potent protective and antiarrhythmic effects when added to the St. Thomas Hospital cardioplegic solution. However, the mechanism of action remains to be elucidated.

• Advances in Traditional Medicine
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• 제3권2호
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• pp.51-55
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• 2003

Resibufogenin is a single compound isolated from the skin venom gland of the toad (Bufo bufo gargarizans cantor). Formulations containing toad venom have been widely used as complementary and alternative medicines. However, like digitalis, resibufogenin possesses both pharmacological and toxicological activities. Our previous data indicated that resibufogenin induces electro-toxicity, including delayed afterdepolarization and triggered arrhythmias at high concentration, both in cardiac fiber in vitro and in beating heart in vivo.

• Journal of The Korean Society of Clinical Toxicology
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• 제4권1호
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• pp.58-60
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• 2006

The venom gland of Toad contains large quantities of cardiac glycosides, and toad venom poisoning is similar to digitalis toxicity and carries a high mortality. Sometimes after ingestion of aphrodisiac pills which contain dried toad, a patient develops gastrointestinal symptoms and bradycardia, psychoneurologic symptoms. We have experienced 2 cases of toad venom intoxication, who ingested asian toads. Patients were presented to our ED with nausea, vomiting, and abdominal pain. The patients were peformed monitoring and conservative treatment and were fully recovered. Toad venom intoxication should be considered in patients with clinical manifestation of gastrointestinal irritation, cardiac arrhythmias, hyperkalemia, and detectable serum digoxin level without current medication of digoxin.

• Journal of Chest Surgery
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• 제25권6호
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• pp.672-677
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• 1992

This is a clinical review of the results from electric cardioversion and pharmacological therapy used in our hospital for reverting cardiac arrythmia in patients with mitral valve surgery between Jan. 1990 and Jun. 1991. Of 62 evaluated patients, 16 patients had regular sinus rhythm and the other 46 had arrhythmias [42; atrial fibrillation 1; atrial flutter 1; premature ventricular contraction] preoperatively. In 2 of patients with sinus rhythm, atrial fibrillation newly developed after surgery and was converted into sinus rhythm soon by intravenous administration of digoxin. Remaining 14 patient resumed sinus rhythm spontaneously. In patients with preoperative arrythmia, 3 patients reverted into sinus rhythm from atrial fibrillation by electric cardioversion at operative field, 1 patient by lidocain and mexiletine, 4 patients by combined use of digoxin and verapamil, 4 patients by 2 times of oral quinidine and 9 patient by long term use of oral amiodarone. Throughout this consecutive trials of anti-arrhythmic drugs and electric cardioversion, Conversion into normal sinus rhythm occurred in 48% of patients with arrhythmia developed after mitral valve surgery.