• Journal of Chest Surgery
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• v.21 no.1
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• pp.62-69
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• 1988

In the department of chest surgery of WonKwang university hospital, mechanical valve replacement was performed in 51 cases from June 1985 to September 1987. Among these, 32 cases were mitral valve replacement, 4 cases were aortic valve replacement, and 15 cases were double valve replacement. 26 cases were male and 25 cases were female and age distribution ranged from 16 years old to 63 years old. Early death within 30 days after operation was 2 cases [3.9%] and causes of death were right heart failure [1] and right ventricular wall rupture [1]. Among 49 early survivors, 2 cases of late death were developed and the causes of death were cardiomyopathy [1] and ventricular arrhythmia [1] Anticoagulant therapy was done with warfarin sodium to the level of 1.5-2 times of normal prothrombin time [20-40%] in 47 survivors. Symptomatically, 93.6% of preoperative NYHA functional class III or IV were converted to the NYHA functional class I or II during follow up.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1924-1925
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• 2007

본 논문에서는 부정맥 판별을 위한 전처리 과정으로 PCA, LDA, ICA를 바탕으로 하여 정확도를 비교하여 보았다. 각각의 전처리는 고유의 특성을 가지고 있으며 본 논문의 목적은 부정맥 판별상 어떤 전처리가 더욱 정확성의 면에서 효과적인지를 알아보는 것이다. 본 논문의 데이터는 MIT-BIH에 기반하고 있으며, Beat의 분류는 정상(Normal), 좌각차단(Left Bundle Branch Block, LBBB), 우각차단(Right Bundle Branch Block, RBBB), 조기심실수축(Premature Ventricular Contraction, PVC), 조기심방수축(Atrial Premature Beat, APB), paced Beat, 심실보충수축(Ventricular Escape Beat)로 나누었다. 실험적 결과는 PCA-BPNN의 경우 95.53%, ICA-BPNN의 경우 93.95%, LDA-BPNN의 경우 96.42%로 LDA가 가장 ECG 부정맥 판별 응용에 있어 가장 효율적인 방법으로 나타났다.

• Korean Journal of Radiology
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• v.20 no.1
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• pp.114-125
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• 2019

Objective: Segmented cardiac cine magnetic resonance imaging (MRI) is the gold standard for cardiac ventricular volumetric assessment. In patients with difficulty in breath-holding or arrhythmia, this technique may generate images with inadequate quality for diagnosis. Real-time cardiac cine MRI has been developed to address this limitation. We aimed to assess the performance of retrospective electrocardiography-gated real-time cine MRI at 3T for left ventricular (LV) volume and mass measurement. Materials and Methods: Fifty-one patients were consecutively enrolled. A series of short-axis cine images covering the entire left ventricle using both segmented and real-time balanced steady-state free precession cardiac cine MRI were obtained. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and LV mass were measured. The agreement and correlation of the parameters were assessed. Additionally, image quality was evaluated using European CMR Registry (Euro-CMR) score and structure visibility rating. Results: In patients without difficulty in breath-holding or arrhythmia, no significant difference was found in Euro-CMR score between the two techniques (0.3 ± 0.7 vs. 0.3 ± 0.5, p > 0.05). Good agreements and correlations were found between the techniques for measuring EDV, ESV, EF, SV, and LV mass. In patients with difficulty in breath-holding or arrhythmia, segmented cine MRI had a significant higher Euro-CMR score (2.3 ± 1.2 vs. 0.4 ± 0.5, p < 0.001). Conclusion: Real-time cine MRI at 3T allowed the assessment of LV volume with high accuracy and showed a significantly better image quality compared to that of segmented cine MRI in patients with difficulty in breath-holding and arrhythmia.

• Journal of Chest Surgery
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• v.19 no.4
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• pp.672-677
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• 1986

From April, 1984 to August, 1986, 214 cases of cardiovascular surgeries had been performed at Yeungnam University Hospital consisting 158 open heart surgeries and 56 non-open heart surgeries. The leading cardiac anomaly of open heart surgeries was ventricular septal defect which was 43% of congenital heart diseases, and most of remaining non-open heart surgeries were ligating patent ductus arteriosus. We had observed 33 postoperative complications such as wound problems, transient arrhythmia, postpericardiotomy syndrome, bleeding requiring reoperation and so on. 3 cases of surgical mortality were present [2 in congenital heart diseases and 1 in acquired heart disease], which resulting 1.9% of surgical mortality rate in the open heart surgeries.

• Journal of The Korean Society of Clinical Toxicology
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• v.5 no.1
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• pp.67-70
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• 2007

Aconitum is an extremely dangerous plant that contains various toxic diterpenoid alkaloids, primarily concentrated in the roots. We report a case of acute intoxication of a 60-year-old man admitted to our emergency department after ingestion of a large amount of homemade aconitine decoction. At presentation about one hour after intake, the patient was unconscious and electrocardiographic analysis showed a ventricular tachycardia/fibrillation. Several times defibrillation was applied and antiarrhythmic agents were administered, but the patient still exhibited a refractory ventricular fibrillation and failed to return to spontaneous circulation. Sustained cardiopulmonary resuscitation finally produced a pulsatile cardiac rhythm at two hours after intake. The patient was discharged from our hospital on day 8. The authors stress that clinicians must be aware of the possible occurrence of life-threatening ventricular arrhythmia in cases of aconitine intoxication and be prepared to persist with prolonged CPR as necessary.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.7
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• pp.1072-1077
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• 2017

Mean-reverting analysis refers to a way of estimating the underlining tendency after new data has evoked the variation in the equilibrium state. In this paper, we propose a new method to interpret the specular portraits of Premature Ventricular Contraction(PVC) arrhythmia by applying K-means unsupervised learning algorithm on electrocardiogram(ECG) data. Aiming at this purpose, we applied a mean-reverting model to analyse Heart Rate Variability(HRV) in terms of the modified poincare plot by considering PVC rhythm as the component of disrupting the homeostasis state. Based on our experimental tests on MIT-BIH ECG database, we can find the fact that the specular patterns portraited by K-means clustering on mean-reverting HRV data can be more clearly visible and the Euclidean metric can be used to identify the discrepancy between the normal sinus rhythm and PVC beats by the relative distance among cluster-centroids.

• The Korean Journal of Emergency Medical Services
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• v.24 no.3
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• pp.155-160
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• 2020

Torsades de pointes refers to polymorphic ventricular tachycardia (PMVT), which is caused by the suppression of potassium channels owing to genetic and electrolytic abnormalities, resulting in the extension of the QT interval. Symptoms range from spontaneous circulation recovery to fainting and sudden death. Defibrillation, magnesium correction, and the use of lidocaine as an antiarrhythmic agent are recommended as treatments for persistent torsades de pointes. Currently, only amiodarone is available in the ambulance; however, torsades de pointes does not respond efficiently to amiodarone because it suppresses potassium channels and increases the refractory period of the myocardium. Lidocaine, in contrast, reduces the relative refractory period of the myocardium caused by suppressing sodium channels; thus, it inhibits the occurrence of and treats arrhythmia. In cases where PMVT did not respond to defibrillation, the administration of lidocaine showed no difference in survival and discharge rates compared to amiodarone. Thus, ambulances must be equipped with provisions to administer lidocaine.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.437-444
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• 2016

Most methods for detecting arrhythmia require pp interval, diversity of P wave morphology, but it is difficult to detect the p wave signal because of various noise types. Therefore it is necessary to use noise-free R wave. In this paper, we propose algorithm for premature contraction arrhythmia classification through ECG pattern analysis and template threshold. For this purpose, we detected R wave through the preprocessing method using morphological filter, subtractive operation method. Also, we developed algorithm to classify premature contraction wave pattern using weighted average, premature ventricular contraction(PVC) and atrial premature contraction(APC) through template threshold for R wave amplitude. The performance of R wave detection, PVC classification is evaluated by using 6 record of MIT-BIH arrhythmia database that included over 30 PVC and APC. The achieved scores indicate the average of 99.77% in R wave detection and the rate of 94.91%, 95.76% in PVC and APC classification.

• Clinical and Experimental Pediatrics
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• v.61 no.11
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• pp.362-365
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• 2018

Purpose: This study aimed to analyze changes in QRS duration and cardiothoracic ratio (CTR) following pulmonary valve replacement (PVR) in patients with tetralogy of Fallot (TOF). Methods: Children and adolescents who had previously undergone total repair for TOF (n=67; median age, 16 years) who required elective PVR for pulmonary regurgitation and/or right ventricular out tract obstruction were included in this study. The QRS duration and CTR were measured pre- and postoperatively and postoperative changes were evaluated. Results: Following PVR, the CTR significantly decreased (pre-PVR $57.2%{\pm}6.2%$, post-PVR $53.8%{\pm}5.5%$, P=0.002). The postoperative QRS duration showed a tendency to decrease (pre-PVR $162.7{\pm}26.4$ msec, post-PVR $156.4{\pm}24.4$ msec, P=0.124). QRS duration was greater than 180 msec in 6 patients prior to PVR. Of these, 5 patients showed a decrease in QRS duration following PVR; QRS duration was less than 180 msec in 2 patients, and QRS duration remained greater than 180 msec in 3 patients, including 2 patients with diffuse postoperative right ventricular outflow tract hypokinesis. Six patients had coexisting arrhythmias before PVR; 2 patients, atrial tachycardia; 3 patients, premature ventricular contraction; and 1 patient, premature atrial contraction. None of the patients presented with arrhythmia following PVR. Conclusion: The CTR and QRS duration reduced following PVR. However, QRS duration may not decrease below 180 msec after PVR, particularly in patients with right ventricular outflow tract hypokinesis. The CTR and ECG may provide additional clinical information on changes in right ventricular volume and/or pressure in these patients.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.329-333
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• 2006

A 9-month-old neutered male German Shepherd dog was referred with the primary complaint of episodic collapse. Apparent abnormal findings were not observed in physical examination, routine biochemistry, and diagnostic imaging studies. In the 12-lead surface ECG after collapse, the dog showed frequent ventricular premature contractions (VPCs) with torsade de pointes. The frequency of VPCs was reduced after lidocaine infusion. Based on the history, findings in event recordings oi the ECG and lidocaine response test, the dog was diagnosed as inherited malignant ventricular tachyarrhythmia. Although the dog was initially responded to oral sotalol therapy, the dog was died suddenly. This report described the first case of malignant ventricular tachyarrhythmia of German Sheperd in Korea.