• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.474-475
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• 2008

심실 빈맥은 심실에서 비정상적인 전기자극 발생으로 인하여 심박수가 분당 $100{\sim}120$회를 초과하는 부정맥 증상을 일컫는다. 심실 빈맥이 발생하는 경우 심박출량이 감소하고, 폐에는 미처 나가지 못한 피가 고이는 경우도 발생하여 심부전증이 나타나거나 심실 세동으로 발전하여 사망에 이를 수 있는, 매우 위험한 부정맥 중의 하나이므로 심실 빈맥 검출은 매우 중요한 사안이다. 따라서 본 연구에서는 R-R 간격 정보를 이용하여 심실 빈맥 부정맥 신호를 실시간으로 검출할 수 있는 신호처리 알고리즘을 구현하고자 하였다.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2008.03a
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• pp.84-84
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• 2008

최근 견관절 질환의 상당수가 관절경 수술로 이루어지고 있다. 좌체위(beath chair position)를 이용한 관절경 수술은 시술 중 관헐적 방법으로의 전환이 용이하고 공간에 대한 orientation을 쉽게 잡을 수 있어 선호되고 있다. 또한 관절경 수술 시 시야 확보를 위해 epinephrine을 혼합한 세척액이 통상적으로 사용되고 있다. 관절경 수술 시 심부 정맥 혈전증(deep vein thrombosis), 가스 색전증, 세척액에 사용하는 epinephrine에 의한 심실성 빈맥 등과 같은 치명적인 부작용이 가끔 보고되어 있다. 관절경하 견관절 수술 도중 심실 빈맥의 발생은 매우 드문 경우이며 이에 대한 보고도 거의 없는 상태이다. 저자들은 2주의 기간 동안 좌체위로 관절경하 견관절 수술을 하는 도중 갑작스럽게 발생한 심실 빈맥 2예를 경험하였기에 원인 및 치료 과정을 보고하고자 한다. 좌체위로 인한 뇌혈류 저하, 가스 색전증 등의 증세는 없었다. 관절경술 도중 세척액에 투입된 소량의 epinephrine이 동시에 체내로 급속히 유입되어 심실 빈맥이 왔으리라 추정하고 있으며, 실험을 통해 이를 증명하고자 하였다.

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.179-186
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• 2009

This paper presents an approach to classify normal and Ventricular Tachycardia/Ventricular Fibrillation(VT/VF) from the Creighton University Ventricular Tachyarrhythmia DataBase(CUDB) using the neural network with weighted fuzzy membership functions(NEWFM). In the first step, wavelet transform is used for producing input values which are used in the next step. In the second step, two numbers of input features are extracted by phase space reconstruction method and peak extraction method using coefficients produced by wavelet transform in the previous step. NEWFM classifies normal and VT/VF beats using two numbers of input features, and then the accuracy rate is 90.13%.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.19-26
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• 2009

This paper presents an approach to classify normal and ventricular tachycardia/fibrillation(VT/VF) from the Creighton University Ventricular Tachyarrhythmia Database(CUDB) using the neural network with weighted fuzzy membership functions(NEWFM) and wavelet transforms. In the first step, wavelet transforms are used to obtain the detail coefficients at levels 3 and 4. In the second step, all of detail coefficients d3 and d4 are classified into four intervals, respectively, and then the standard deviations of the specific intervals are used as eight numbers of input features of NEWFM. NEWFM classifies normal and VT/VF beats using eight numbers of input features, and then the accuracy rate is 90.1%.

• Journal of Chest Surgery
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• v.43 no.2
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• pp.180-183
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• 2010

Submitral left ventricular aneurysm (SMLVA) is a rare disease entity that exclusively occurs in the black population. We herewith report on a surgical case of SMLVA in a 68-year-old male who presented with ventricular tachycardia. He underwent surgical repair under standard hypothermic cardiopulmonary bypass. In the state of apical elevation, a vertical ventriculotomy was made directly over the aneurysm, which was located at the posterobasal aspect of the left ventricle. Radiofrequency ablation was performed on the endocardium all around the neck of the aneurysm and then patch endoaneurysmorrhaphy was carried out with particular care not to injure the mitral valve and subvalvular structure. His postoperative recovery was uneventful. There has been no dysfunction of the mitral valve or recurrence of the ventricular tachycardia at 2 years' follow-up.

• Korean Journal of Biological Psychiatry
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• v.1 no.1
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• pp.124-128
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• 1994

We report a case of antipsychotics induced torsade de pointes in a 42-year-old female schizophrenic patient. The patient had taken perphenazine 20 mg/day, chlorpromazine 100 mg/day, and trifluoperazine 15 mg/day irregularly for about 8 years. She experienced syncope and a few difficulties in breathing. On EKG(electrocardiography), QT interval was delayed and polymorphic QRS complexes and ventricular tachycardia were observed. Following a switch of the antipsychotics to haloperidol, known to have fewest effects on the cardiac rhythms among antipsychotics, the arhythymias disappeared. However after discharge, as dose of haloperidol was increased, the symptoms such as chest discomforts and syncopes reappeared. We concluded that the torsade de pointes was developed by antipsychotics. The most common cause of sudden death in patients receiving antipsychotic treatment appears to be ventricular tochycardia. Therefore, clinician should be well aware of the possible side effects of antipsychotics and be cautious in prescribing such drugs to their patients.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.639-645
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• 1996

A 14-year-old male patient with previous surgical repair of tetralogy of Fallot was admitted with hemodynamically significant ventricular tachycardia (VT). On preoperative electrophysiologic study (EPS), the morphology of documented VT was RBBB of vertical axis with 320 msec cycle length. The endocardial mapping during VT delineated the origin of VT at right ventricular outflow tract (RVOT), where the patch was attached. The clinical VT had a clockwise reentry circuit around the patch with the earliest activation at the same site seen during the preoperative EPS. The previously placed right ventricular outflow patch and fibrous tissue were removed. During a postoperative EPS, it was no longer possible to induce the VT. Ventricular tachycardia following repair of tetralogy of Fallot seen in this patient was caused by a macro-reentry around the right ventricular outflow patch. We were able to ablate the VT with the aid of a detailed mapping of its epicardial activation sequence.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.5 s.305
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• pp.27-34
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• 2005

Ventricular fibrillation(VF) is generally caused by chaotic behavior of electrical propagation in heart and may result in sudden cardiac death. In this study, we proposed a ventricular fibrillation detection algorithm based on support vector machine classifier, which could offer benefits to reduce the teaming costs as well as good classification performance. Before the extraction of input features, raw ECG signal was applied to preprocessing procedures, as like wavelet transform based bandpass filtering, R peak detection and segment assignment for feature extraction. We selected input features which of some are related to the rhythm information and of others are related to wavelet coefficients that could describe the morphology of ventricular fibrillation well. Parameters for SVM classifier, C and ${\alpha}$, were chosen as 10 and 1 respectively by trial and error experiments. Each average performance for normal sinus rhythm ventricular tachycardia and VF, was 98.39%, 96.92% and 99.88%. And, when the VF detection performance of SVM classifier was compared to that of multi-layer perceptron and fuzzy inference methods, it showed similar or higher values. Consequently, we could find that the proposed input features and SVM classifier would one of the most useful algorithm for VF detection.

• Journal of Chest Surgery
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• v.39 no.5 s.262
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• pp.399-402
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• 2006

Stent thrombosis is a rare complication after percutaneous coronary intervention (PCI), but it might be related to fatal outcomes. We report a case of patient who suffered from acute myocardial infarction complicated with cardiogenic shock and ventricular tachycardia caused by stent thrombosis and successfully resuscitated by percutaneous cardiopulmonary bypass support.

• Journal of Chest Surgery
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• v.35 no.10
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• pp.745-749
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• 2002

Cardiac rhabdomyoma is a rare type of benign tumor affecting the heart. There are a few previous reports of intracardiac rhabdomyomas causing ventricular arrythmia. We describe a 1-year-old female tuberous sclerosis patient who was presented with a ventricular tachycardia. Diagnostic echocardiography revealed two masses in the left ventricular outflow tract originating from the ventricular septum. The masses were surgically resected through aortotomy using cardiopulmonary bypass and the masses appeared benign. The pathology was that of a cardiac rhabdomyomas. Postoperative course was uneventful and the ventricular tachycardia was controlled.