• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.192-200
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• 2015

Several algorithms have been developed to classify arrhythmia which rely on specific ECG(Electrocardiogram) database. Nevertheless personalized difference of ECG signal exist, performance degradation occurs because of carrying out diagnosis by general classification rule. Most methods require accurate detection of P-QRS-T point, higher computational cost and larger processing time. But it is difficult to detect the P and T wave signal because of person's individual difference. Therefore it is necessary to classify the pattern by analyzing personalized ECG signal and extracting minimal feature. Thus, QRS pattern Analysis of personalized ECG Signal by Q, R, S peak variability is presented in this paper. For this purpose, we detected R wave through the preprocessing method and extract eight feature by amplitude and phase variability. Also, we classified nine pattern in realtime through peak and morphology variability. PVC, PAC, Normal, LBBB, RBBB, Paced beat arrhythmia is evaluated by using 43 record of MIT-BIH arrhythmia database. The achieved scores indicate the average of 93.72% in QRS pattern detection classification.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.766-770
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• 2008

Primary tumors of the heart are uncommon among pediatric patients. Rhabdomyoma is the most frequent cardiac tumor in infants and children, which is commonly associated with tuberous sclerosis. Tuberous sclerosis is a neurocutaneous syndrome affecting the brain, heart, skin, and other organs. Cardiac rhadomyomas are reported in 50-64% of infants with tuberous sclerosis. Tuberous sclerosis involves multiple locations in the atrium, ventricle and septum, and may induce mechanical obstruction of the outflow tract and heart failure depending on the location, number, size, and degree of invasion of tumors. Arrhythmias may also develop in infants with cardiac rhadomyomas, but only a few of these patients require prolonged anti-arrhythmic therapy because arrhythmia often disappears with spontaneous regression of the tumors, and the ultimate prognosis may be decided by the cerebral manifestations.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.624-630
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• 2010

As electrocardiogram(ECG) signals are generally sampled with a frequency of over 200Hz, a method to compress diagnostic information without losing data is required to store and transmit them efficiently. In this paper, an ECG signal compression method, which uses feature points based on curvature, is proposed. The feature points of P, Q, R, S, T waves, which are critical components of the ECG signal, have large curvature values compared to other vertexes. Thus, these vertexes are extracted with the proposed method, which uses local extremum of curvatures. Furthermore, in order to minimize reconstruction errors of the ECG signal, extra vertexes are added according to the iterative vertex selection method. Through the experimental results on the ECG signals from MIT-BIH Arrhythmia database, it is concluded that the vertexes selected by the proposed method preserve all feature points of the ECG signals. In addition, they are more efficient than the AZTEC(Amplitude Zone Time Epoch Coding) method.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1163-1185
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• 2021

Sudden cardiac death is an unexpected death originating from the heart that occurs within an hour of the onset of symptoms. The main cause of sudden cardiac death is arrhythmia; however, diagnosing underlying structural heart disease significantly contributes to predicting the long-term risk. Cardiovascular CT and MR provide important information for diagnosing and evaluating structural heart disease, enabling the prediction and preparation of the risk of sudden cardiac death. Therefore, we would like to focus on the various structural heart diseases that increase the risk of clinically-important sudden cardiac death and the importance of imaging findings.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.525-531
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• 1999

Background: We analyzed five hundred patients who underwent either isolated or concomitant coronary artery bypass grafting(CABG) between November 1981 and June 1997. Material and Method: There were 330 males and 170 females with a mean age of 57.4$\pm$8.9 years. To evaluate the preoperative status, we performed electrocardiograghy, echocardiography, MIBI scan, Duplex sonogram, common blood test including CK and LDH and coronary angiography. Result: Preoperative clinical diagnoses were unstable angina in 282 (56.4%), stable angina in 141 (28.2%), postinfarction angina in 58 (11.6%), acute myocardial infarction in 8 (1.6%), variant angina in 7 (1.4%) and failed percutaneous transluminal coronary angioplasty in 4 (0.8%) patients. Preoperative angiographic diagnoses were three-vessel disease in 263 (52.6%), two-vessel disease in 93 (18.6%), one-vessel disease in 71 (14.2%), left main disease in 68 (13.6%), and others in 5 (1.0%) patients. Patients had various risk factors for coronary disease, and the frequency of the risk factors such as hypertension, diabetes and smoking showed increasing tendency year by year. We used saphenous vein grafts in 1143, internal thoracic artery grafts in 442, radial artery graft in 17, and gastroepiploic artery graft in 1 anastomosis. The mean number of grafts was 3.2$\pm$1.2 per patient. Concomitant operations were prosthetic valve replacement or valvuloplasty in 31, coronary endarterectomy and angioplasty in 27, left main coronary angioplasty in 13, carotid endarterectomy in 5, and neurologic problems, bleeding, and perioperative myocardial infarction. The mean follow-up period was 25$\pm$23 months and there were 5 cases of reoperation. Conclusion: We hope that the surgical results would improve with the accumulation of experience, application of new myocardial protection technique, and timely intervention of mechanical assisted devices.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.1-8
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• 2002

Atrial fibrillation(AF). chronic or paroxysmal is the most frequent arrhythmia in human subjects Duration of P wave in signal-averaged electrocardiography(SAECG) reflects intra-atrial conduction time and therefore. could be used as an electrophysiological marker for atrial conduction chance at the earthy stave. So we apply the analysis method using SAECG to diagnose Paroxysmal atrial fibrillation(PAF) . Subjects Participated for the study consisted of two groups: a control group(n=34) of normal healthy volunteers and a group of AF Patients(n=38) with a documented history of PAF but no other history of cardiac disease. We evaluated the effect of several filtering and determination methods to find the starting and ending feints of the P wavy on its duration. To increase the measurement reliability of P wave duration. the automatic detection method was proposed. Also. to increase the detection rate for PAF risk, the decision threshold value was optimized using receiver operation characteristics(ROC) curve. Results showed that the highest statistical difference (p〈0.001) of the P wane duration between controls and subjects was obtained at the Processing condition, using absolute threshold vague(8.75 $\mu N$) , a least mean square(LMS) high pass filter and 30 Hz cutoff frequency. The most outstanding difference(sensitivity 88 % specificity 64.4 %) between controls and subjects was obtained at the decision threshold value of 112 ms.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.268-271
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• 2007

Purpose : Premature narrowing of the foramen ovale is rare but serious clinical entity. Prenatal narrowing or obstruction of the foramen ovale shows symptoms such as right heart failure, fetal hydrops, triscupid regurgitation, left heart obstructive disease, and supraventricular tachycardia. This study aimed to assess the prenatal diagnosis and postnatal clinical course of restrictive foramen ovale in utero in otherwise normal heart. Methods : The subjects were five patients diagnosed with restrictive foramen ovale in utero from January 2001 to June 2005 at Chungnam National University Hospital. The diagnostic criteria was defined when the maximum diameter in a 4-chamber view is less than 2.5 mm and there is a continuous doppler velocity at the foramen ovale of more than 0.6m/s. Results : At the time of diagnosis of restrictive foramen ovale, gestation age was 34~37 wks, and chief complaints were fetal arrhythmia(2 cases), pericardial effusion, Ebstein anomaly and subaortic stenosis. Two cases which were diagnosed fetal hydrops and supraventricular tachycardia delivered by emergent cesarian section. Five cases were found to have right heart dilatation on echocardiogram after birth, but right heart dilatation became normalized at day 7 after birth and the clinical courses were not eventful. Conclusion : Identifying an obstructed foramen ovale in the fetus warrants the further search for additional cardiac and extracardiac anomalies, which may alter the prognosis. Delivery should be induced if possible in cases of foramen ovale obstruction with signs of cardiac decompensation.

• Journal of Chest Surgery
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• v.38 no.7 s.252
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• pp.476-482
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• 2005

Recently, coronary artery obstructive disease and coronary artery bypass graft surgery have increased, and the operative result has been improved. We reviewed 154 cases of coronary artery bypass graft surgery from Jan. 1985 to Jun. 2004. Material and Method: We reviewed 148 patients, 154 cases of coronary artery bypass surgery from Jan. 1985 to Jun. 2004. This investigation is designed to illustrate the preoperative diagnosis, severity of disease, operative method, the kind of used bypass graft used, number of distal anasomosis, associated surgery, and postoperative morbidity and mortality. Result: There were 84 males, 64 females and the average age was $58.9\pm8.3$ years old. Preoperative clinical diagnosis were unstable angina in 97 cases $(63.0\%)$, stable angina in 31 cases $(20.1\%)$, acute myocardial infarction in 12 cases $(7.8\%)$ and postinfartion angina in 14 cases $(9.1\%)$. Preoperative angiographic diagnosis were three-vessel disease in 68 $(44.2\%)$, two-vessel disease in 39 $(25.3\%)$, one-vessel disease in 35$(22.7\%)$, and left main disease in 12$(7.8\%)$ cases. There were 78 cases of on-pump coronary artery bypass graft surgery and 76 cases of off-pump coronary artery bypass graft surgery. The total distal anastomoses number was 319, mean number of anastomoses was $2.06\pm0.96$. There were 10 concomitant procedures. Postoperative intra-aortic balloon pump was used in 21$(13.6\%)$ cases, but only 4 cases were used at off-pump coronary artery bypass surgery. Total early mortality was $7.8\%$. The mortality was decreased as $4.5\%$ from Jan. 2001 to Jun. 2004. Post operative complication was perioperative yocardial infarction in 9cases$(5.8\%)$, low cardiac output syndrome in 17 cases$(11\%)$, and arrhythmia in 30 cases$(19.5\%)$ cases. Conclusion: Since 1985, The result of coronary artery bypass graft surgery has been improved because of more refined technique, use of off-pump coronary artery bypass surgery, use of internal thoracic artery and radial artery as bypass graft. We should study the long-term follow up more for better operative results.

• Journal of Veterinary Clinics
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• v.32 no.1
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• pp.101-104
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• 2015

A 4-years-old, intact male Golden retriever dog was presented with abdominal distension and dyspnea. Physical examination revealed arrhythmia and cardiac murmur. Generalized cardiomegaly, pleural effusion and ascites were shown on thoracic and abdominal radiographs. Two-dimensional echocardiography revealed abnormal mitral and tricuspid valve motion, mitral and tricuspid regurgitation, left ventricular eccentric hypertrophy and left atrial dilation. Color-flow Doppler imaging revealed turbulent flow extending into the left ventricle during diastole from the mitral valve orifice, and into the left atrium during systole. Spectral Doppler recordings revealed highly increased early diastolic mitral valve inflow and prolonged pressure half-time of mitral inflow. Based on the echocardiographic examination, the diagnosis was made as the mitral valve dysplasia concurrent with mitral valve stenosis and tricuspid valve dysplasia.

• Journal of Chest Surgery
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• v.40 no.3 s.272
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• pp.228-231
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• 2007

Chest trauma can lead to various cardiac complications ranging from arrythmia to myocardial rupture. Coronary artery injury in patients with blunt chest trauma is rare, and traumatic aneurysm of the left coronary artery is even more unusual than right coronary artery. Injury to the coronary arteries, including intimal aneurysm, dissection, laceration, arteriovenous fistula and thrombosis, are sequelae that rarely occur after a blunt trauma. Occlusion of the coronary artery results is a serious complication for the patient via acute myocardial infarction, We report here on a case of acute myocardial infarction with coronary artery aneurysm that arose from blunt chest trauma in a 33-year-old male, and he was successfully managed by a coronary bypass graft without performing cardiopulmonary bypass.