• The Korean Journal of Physiology
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• 제26권2호
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• pp.99-111
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• 1992

Permissive action of thyroid hormone at the level of Ca channel and responsible mechanisms underlying thyroid hormone-induced change in myocardial contractile state and $T_3-induced$ arrhythmias were investigated in rabbit ventricular or atrial myocytes using whole cell patch clamp technique. Single cells were isolated by Langendorff perfusion with collagenase. Cardiac myocytes were incubated in $low-Cl^-,$, $high-K^+$ medium containing $1_{\mu}M\;L-triiodothyronine\;(T_3)$ at $4^{\circ}C$ for 2.10 hours. The calcium currrent $(I_{Ca})$ was increased in $T_3$ loaded cells, however, the shape of current voltage curve and reverse potential did not altered. Cyclic AMP, cyclic GMP, isoprenaline and 3-isobutyl-1-methyl-xanthine increased $I_{Ca}$ in euthyroid and hyperthyroid conditions, and acetylcholine blocked the increase of $I_{Ca}\;in\;T_3$ loaded cells. The amplitude of $I_{Ca}$ was much larger after perfusing cGMP than cGMP in both conditions, whereas the degree of increase of $I_{Ca}$ was greater after perfusing cAMP than cGMP in $T_3$ loaded cells. The degree of increase of $I_{Ca}$ after perfusing isoprenaline or IBMX also was greater in $T_3$ loaded cells than in control cells. Background current induced by isoprenaline also increased in $T_3$ loaded cells. The Ca release dependent inward current was increased in amplitude but its activation and inactivation time course was not changed in $T_3$ loaded cells. Activation of Na pump current was not changed in $T_3$ loaded cells. From the above results it is suggested that thyroid hormone induced increase in the contractile state of cardiac myocytes are accompanied by augmented $I_{Ca}$ and the increase of Ca release from sarcoplasmic reticulum and the permissive action of thyroid hormone to catecholamines could induce arrhythmias through the increase of $I_{Ca}$ and background current.

• Progress in Superconductivity
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• 제7권1호
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• pp.28-35
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• 2005

We propose a method to measure atrial arrhythmias (AA) such as atrial fibrillation (Afb) and atrial flutter (Afl) with a SQUID magnetocardiograph (MCG) system. To detect AA is one of challenging topics in MCG. As the AA generally have irregular rhythm and atrio-ventricular conduction, the MCG signal cannot be improved by QRS averaging; therefore a SQUID MCG system having a high SNR is required to measure informative atrial excitation with a single scan. In the case of Afb, diminished f waves are much smaller than normal P waves because the sources are usually located on the posterior wall of the heart. In this study, we utilize an MCG system measuring tangential field components, which is known to be more sensitive to a deeper current source. The average noise spectral density of the whole system in a magnetic shielded room was $10\;fT/{\surd}Hz(a)\;1\;Hz\;and\;5\;fT/{\surd}Hz\;(a)\;100\;Hz$. We measured the MCG signals of patients with chronic Afb and Afl. Before the AA measurement, the comparison between the measurements in supine and prone positions for P waves has been conducted and the experiment gave a result that the supine position is more suitable to measure the atrial excitation. Therefore, the AA was measured in subject's supine position. Clinical potential of AA measurement in MCG is to find an aspect of a reentry circuit and to localize the abnormal stimulation noninvasively. To give useful information about the abnormal excitation, we have developed a method, separative synthetic aperture magnetometry (sSAM). The basic idea of sSAM is to visualize current source distribution corresponding to the atrial excitation, which are separated from the ventricular excitation and the Gaussian sensor noises. By using sSAM, we localized the source of an Afl successfully.

• 수면정신생리
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• 제4권2호
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• pp.129-139
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• 1997

수면 무호흡을 포함한 다양한 원인의 수면과 관련된 호흡장애를 동반한 환자들에서는 여러가지 심혈관계 기능부전이 초래되어 이들 환자의 임상경과에 중대한 영향을 미친다. 수면 무호흡증후군, 특히 폐쇄성 수면 무호흡증후군은 수면장애의 여러 가지 원인 중 임상영역에서 가장 흔히 볼수 있는 질환으로 전신성 고혈압, 심부정맥, 폐동맥 고혈압 및 우심실 부전, 협심증 및 심근경색증, 뇌졸증등의 발병률이 정상인에 비하여 현저히 높은 것으로 알려져 있다. 폐쇄성 수면 무호흡과 달리 중추성 수면 무호흡은 수면중에 호흡중추를 불안정하게 하는 다양한 원인에 의해 발생하며 역시 심혈관계의 기능에 영향을 미칠 수 있다. 수면중에 환기장애가 더욱 악화될 수 있는 호흡기계 질환이 있는 환자들은 수면 무호흡증후군과 달리 만성적인 저산소증과 고탄산증이 동반되며 이로 인해 심부정맥, 폐동맥 고혈압, 우심실 부전(폐성심) 등의 심혈관계 이상이 초래될 수 있다. 따라서 수면 무호흡을 포함한 수면과 관련된 호홉 장애의 진단과 치료에 있어서는 호흡기계 질환에 대한 정확한 평가와 더불어 동반될 수 있는 심혈관계의 기능부전에 대한 정밀한 분석이 반드시 필요하며, 이들 자료를 바탕으로 기관절개술, 기계적 호흡, 지속적 양압공급치료, 적절한 산소요법 등의 적극적이고도 효과적인 치료법을 적용함으로서 심혈관계 합병증의 발생과 이로 인한 사망률을 감소시킬 수 있을 것으로 생각된다.

• Tuberculosis and Respiratory Diseases
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• 제42권4호
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• pp.610-617
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• 1995

저자들은 활동성 선단거대증과 이로 인하여 생긴 확장형 성근병증에 의한 울혈성 심부전과 중증의 심실성 부정맥이 있는 환자에 동반된 폐쇄성 수면 무호흡증후군을 치료하기 위하여 4개월간 지속적 영양공급치료를 시행한 예를 경험하였기에 문헌고찰과 함께 보고한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권1호
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• pp.99-118
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• 2013

Electrocardiograms (ECGs) are widely used by clinicians to identify the functional status of the heart. Thus, there is considerable interest in automated systems for real-time monitoring of arrhythmia. However, intra- and inter-patient variability as well as the computational limits of real-time monitoring poses significant challenges for practical implementations. The former requires that the classification model be adjusted continuously, and the latter requires a reduction in the number and types of ECG features, and thus, the computational burden, necessary to classify different arrhythmias. We propose the use of adaptive learning to automatically train the classifier on up-to-date ECG data, and employ adaptive feature selection to define unique feature subsets pertinent to different types of arrhythmia. Experimental results show that this hybrid technique outperforms conventional approaches and is therefore a promising new intelligent diagnostic tool.

• Journal of Chest Surgery
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• 제47권4호
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• pp.434-436
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• 2014

Left ventricular thrombus is a common complication related to acute myocardial infarction. Removing this with an incision of the free wall of the left ventricle may cause fatal cardiac dysfunction or arrhythmias. Furthermore, performing incision and suture on the fragile myocardium of an acute myocardial infarction patient may cause serious bleeding complications. If there is a patient with left ventricular thrombus who needs thoracotomy for another reason, the case is attempted with the thought that if effective intraventricular visualization and manipulation can be done, fatalities caused by incision and suture may be reduced. For patients undergoing cardiopulmonary bypass, if intracardiac manipulation is required, an endoscope can be used, and given the potential complications after the incision and suturing of the infarcted tissue, the benefits are deemed sufficient.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권2호
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• pp.162-166
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• 2001

Obstructive sleep apnea syndrome(OSAS) is a complex sleep disorder characterized by intermittent apnea secondary to sleep-induced obstruction of the upper airway. It occurs because of an airway obstruction anywhere between the trachea and the oronasal apparatus. The hallmark of OSAS is snoring, which is caused by vibration of the tissues of the pharynx as the airway narrows. The consequences of OSAS have focused on excessive daytime sleepiness resulting from sleep fragmentation and the cardiovascular derangements producing hypertension and arrhythmias. The primary method of controlling OSAS has been surgery. The current surgical procedures used for OSAS are tracheostomy, tonsillectomy, nasal septoplasty, uvulopalatopharyngoplasty, anterior mandibular osteotomy with hyoid myotomy and suspension, and maxillary, mandibular and hyoid advancement. We report a case of OSAS that was improved by genial advancement with infrahyoid myotomy and suspension. The patient was objectively documented by polysomnography, cephalometric analysis, and physical examination before the surgical procedure. The patient underwent genial advancement with infrahyoid myotomy and suspension. Patient had a good response from surgery.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권2호
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• pp.988-1001
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• 2018

Arrhythmia has recently emerged as one of the major causes of death in Koreans. Premature Ventricular Contraction (PVC) is the most common arrhythmia that can be found in clinical practice, and it may be a precursor to dangerous arrhythmias, such as paroxysmal insomnia, ventricular fibrillation, and coronary artery disease. Therefore, we need for a method that can detect an abnormal heart beat and diagnose arrhythmia early. We extracted the features corresponding to the QRS pattern from the subject's ECG signal and classify the premature ventricular contraction waveform using the features. We modified the weighting and bias values based on the error back-propagation algorithm through learning data. We classify the normal signal and the premature ventricular contraction signal through the modified weights and deflection values. MIT-BIH arrhythmia data sets were used for performance tests. We used RR interval, QS interval, QR amplitude and RS amplitude features. And the hidden layer with two nodes is composed of two layers to form a total three layers (input layer 0, output layer 3).

• Journal of Chest Surgery
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• 제17권4호
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• pp.657-665
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• 1984

Thirty-seven patients had undergone repair of a endocardial cushion defect between 1977 and Aug. 1983 in Seoul National University Hospital. Twenty eight had a partial defect, one intermediate defect and eight complete endocardial cushion defect. Tricuspid cleft was found in 4 cases and mitral cleft was in all p-ECD. Seven patients were of type C anatomy in c-ECD. Four patients had associated major anomalies, including three TOF in c-ECD, one coarctation in p- ECD. In p-ECD patients, the septal defect was closed with patch in all cases and the atrioventricular valvular insufficiency was corrected with MVR in 4 cases, TVR in 1 case and simple interrupted sutures in remainders. In c-ECD patients the septal defect was closed with single patch except one case. The atrioventricular valve was repaired with simple interrupted sutures except one MVR and TVR case. The operative mortality was 14.2% in p-ECD, 44.4% in c-ECD, but recent 3 years [1980-1983] mortality was 8.7% in p-ECD, 20% in c-ECD. More than grade III systolic regurgitant murmur was oted postoperatively in 4 cases of c-ECD and 3 cases of p-ECD. The operative risk factors were preoperative NYHA classification, cyanosis, Rp/Rs, systolic pressure of main pulmonary artery and the degree of regurgitation of atrioventricular valves. The causes of death were low cardiac output syndromes, pulmonary complications and arrhythmias.

• Journal of Chest Surgery
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• 제32권8호
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• pp.749-752
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• 1999

최근 여러 병원에서 선천성 수정대혈관전위의 해부학적 교정이 보고되고 있다. 해부학적 교정을 받은 수 정대혈관전위 환아의 단기 및 장기추적에서 문제가 되는 것은 주로 심방전환수술에 따르는 대정맥과 심방 문합 부\ulcorner의 협착과 상심실성 부정맥이며 이는 심방이 작은 경우에 위험도가 증가되고 특히 심첨과 대정맥 이 동측에 있는 경우에는 문제가 된다. 이런 경우 이중전환수술시 일부 선택된 환아에서 대정맥폐동맥단락 술을 추가함으로써 수술의 위험성과 심방의 잠재성 합병증을 피할 수 있다고 여겨진다. 본원에서는 수정대 혈관전위, 심실중격결손, 폐동맥폐쇄가 있으면서 심첨과 대정맥이 동측에 있는 환아의 해부학적 교정시에 대 정맥폐동맥단락술을 추가하여 좋은 결과를 얻었기에 보고하는 바이다.