• Journal of the Korean Institute of Intelligent Systems
• /
• v.23 no.6
• /
• pp.519-526
• /
• 2013

ECG signal has the feature that is repeated in a cycle of P, Q, R, S, and T waves and is sampled at a high sampling frequency in general. By using the feature of periodic ECG signals, maximizing compression efficiency while minimizing the loss of important information for diagnosis is required. However, the periodic characteristics of such amplitude and period is not constant by measuring time and patients. Even though measured at the same time, the patient's characteristics display different periodic intervals. In this paper, an adaptive multi-level coding is provided by coding adaptively the dominant and non-dominant signal interval of the ECG signal. The proposed method can maximize the compression efficiency by using a multi-level code that applies different compression ratios considering information loss associated with the dominant signal intervals and non-dominant signal intervals. For the case of long time measurement, this method has a merit of maximizing compression ratio compared with existing compression methods that do not use the periodicity of the ECG signal and for the lossless compression coding of non-dominant signal intervals, the method has an advantage that can be stored without loss of information. The effectiveness of the ECG signal compression is proved throughout the experiment on ECG signal of MIT-BIH arrhythmia database.

• Journal of Chest Surgery
• /
• v.24 no.4
• /
• pp.404-420
• /
• 1991

Surgical treatment of congenital and acquired heart disease preceded the development of accurate techniques for diagnosis, heart lung machine and cardiopulmonary bypass, intraoperative myocardial protection, operative techniques and cardiac anesthesia. For 5 years from Sep. 1985 to Sep. 1990, six hundred cases of open heart surgeries [OHS] were performed in the department of Thoracic & Cardiovascular Surgery, Pusan Paik Hospital, College of Medicine, Inje University. The results were summarized as follows. 1. The annual number of OHS[cases per year] was above 100 since 1987, and the increasing rate of cases was 23.5% per year since 1986. 2. Among the total 600 cases, there were 470 cases of congenital heart diseases and 130 cases of acquired. Age range of the congenital patients was 8 months to 44 years with the mean age of 10 years, and acquired patients was 16 to 56 years with the mean age of 36 years. 3. Among the 470 congenital anomalies, there were 429 cases of acyanotic and 41 cyanotic patients. Totally, VSD was 286 cases[60.6%], ASD 103 cases[21.9%], TOF 35 cases [7.4%], PS 20 cases [4.1%], ECD 12 cases [2.0%], Ebstein`s anomaly 3 cases [0.6%], Valsalva sinus rupture 3 cases [0.6%] and others. The appropriate one stage radical operations were applied to the all congenital cases with the result of 2.6% immediate postoperative hospital mortality rate. 4. Among the 130 acquired cases, there were 122 cases of valvular heart diseases, 6 of heart tumors [5 myxoma, one malignant histiocytoma], one of LA thrombus and one of annuloaortic ectasia. Cardiac tumors and LA thrombus were removed through the atrial septal approach. Bentall procedure was adopted to the annuloaortic ectasia case. AVR, MVR and TVA [DeVega procedure] were applied to 120 valve diseases, and there were also one of OMC and one of MVA[Jerome-Kay procedure]. 5. Among the 120 valve replacement cases, there were 87 of single valve replacement cases [AVR: 8, MVR: 79], 11 of double valve replacement [AVR+MVR: 11], 12 of MVR+TVR and 10 of MVR+AVR+TVA. The total number of implanted prosthetic valves were 141. In MVR, 45 of St. Jude Medical valves, 63 of Carpentier-Edward valves and 4 of Ionescu-Shiley valves were used. In AVR, 18 of St. Jude Medical valves and 11 of Carpentier-Edward valves were used. in MVR, 29mm and 31mm sized valves were used mostly and In AVR, 23mm sized valves were used mostly. 6. Postoperatively many kinds of complications were occurred. Among them, wound problems [30 cases], low output syndrome [29 cases], arrhythmia [20 cases], pleural effusion and pneumothorax [13 cases] were occurred frequently. The postoperative immediate hospital mortality was 3.0% in total [congenital 2.6%, acquired 4.6%].

• Journal of Chest Surgery
• /
• v.40 no.2 s.271
• /
• pp.136-139
• /
• 2007

Bilateral popliteal artery entrapment syndrome is a rare vascular disease, which leads to ischemic claudication as a result of disturbance to the blood flow from the abnormal relationship of the popliteal artery to the gastrocnemius muscle, a fibrous band or the popliteus muscle in the young male population. A 58-years-old male patient, complaining of ischemic claudication, coldness and 3rd toe gangrene of left leg of 1 month's duration was admitted to our institution. His left ankle-brachial index was decreased; therefore, a femoral artery angiography was peformed, which revealed a total occlusion below the distal superficial femoral artery of the left leg. An EKG revealed atrial fibrillation, suggestive of a thromboembolism of the popliteal artery due to atrial fibrillation; therefore, Urokinase thrombolysis was attempted. After the Urokinase thrombolysis, popliteal artery entrapment syndrome was diagnosed, with MRI then performed for an anatomical diagnosis. The popliteal artery entrapment was type 1, where the popliteal artery was displaced medial to the Gastrocnemius head. After complete removal of the popliteal artery aneurysm, interposition was performed with a contra lateral greater saphenous vein graft. A mild right popliteal artery aneurysm still remained, but surgery was not performed. Currently, the patent is surviving, without complications. Herein, the good results obtained for the surgical treatment of a severely affected leg, and the conservative treatment of a mildly affected leg, are reported.

• Journal of Chest Surgery
• /
• v.35 no.12
• /
• pp.862-870
• /
• 2002

The surgical results of the patients with single ventricle(SV) associated with total anomalous pulmonary venous connection(TAPVC) has been reported with high mortality and morbidity due to their morphologic and hemodynamic complexity. A retrospective review was undertaken to report the outcome of the first-stage palliative surgery in our institution and to determine the factors influencing early death. Material and Method: Between January 1987 and June 2002, 39 patients with SV and TAPVC underwent surgical intervention with or without TAPVC repair. Age at operation ranged from 1day to 10.7months (median age, 2.4month), and 29 patients were male. Preoperative diagnosis included 20 right-dominant SV, 15 SV with endocardial cushion defect, 3 left-dominant SV, and 1 tricuspid atresia. The pulmonary venous connection was supracardiac in 22, cardiac in 5, infracardiac in 11, and mixed in 1, Obstructed TAPVC was present in 11. First-stage palliative surgery was performed in 37. Repair of TAPVC, either alone or in association with other procedures, was performed during the initial operation in 31. Univariate and multivariate analyses were performed to analyze the risk factors influencing the operative death. Result: A mean follow-up period of survivors was 34.3 $\pm$ 43.0(0.53 ~ 146.2)months. Overall early operative mortality was 43.6%(17/39). The causes were low cardiac output in 8, failure of weaning from cardiopulmonary bypass in 3, sepsis in 2, pulmonary hypertensive crisis in 1, pulmonary edema in 1, pneumonia in 1, and postoperative arrhythmia in 1. Risk factors influencing early death in univariate analysis were body weight, surgical intervention in neonate, obstructive TAPVC, preoperative conditions including metabolic acidosis, and need for inotropic support, TAPVC repair in initial operation, operative time, and cardiopulmonary bypass(CPB) time. In multivariable analysis, body weight, age at initial operation, surgical intervention in neonate, preoperative conditions including metabolic acidosis, need for inotropic support and CPB time were the risk factors. Conclusion: In this study, we demonstrated that the patients with SV and TAPVC had high perioperative mortality. Preoperative poor condition, young age, the length of operative and CPB time, the presence of obstructive TAPVC had been proven to be the risk factors. This fact suggests that the avoidance of unnecessarily additional procedures may improve the surgical outcomes of the first-stage palliative surgery. However further observation and collection of the data is mandatory to determine the ideal surgical strategy.

• Journal of Chest Surgery
• /
• v.38 no.9 s.254
• /
• pp.609-615
• /
• 2005

Background: Some controversy still exists concerning the operative indications of coronary fistulas. Nevertheless, a short-term and long-term outcomes are excellent with surgical interventions. In this study, we assessed our surgical results on this disease entity during the last 20 years. Anatomic diversity was described as well. Material and Method: From April 1986 to March 2005, 20 patients with coronary fistulas underwent surgical correction in Seoul National University Children's Hospital. Their medical records were reviewed retrospectively. Result: Twelve patients ($60\%$) were asymptomatic prior to surgery. All had electrocardiogram and echocardiogram and all but 3 had coro-nary angiogram preoperatively. Anatomically, none of them had two or more coronary fistulas. The sites of origin were left coronary system in 11 patients and right in 9. The draining sites were right ventricle in 11, right atrium in 3, left ventricle in 3, main pulmonary artery in 2, and superior vena cavae in 1. All of the involved, the coro-nary arteries were dilated or aneurismal. In 1 case, there was atherosclerotic change but no ischemic evidence in preoperative electrocardiogram. Operative techniques included external obliteration (13), internal obliteration (5), and both (2). External obliteration was done by ligation of the fistulous tract only in T patients, by fstula ligation plus plication in 3 and by plication or patch closure via fistulotomy in 3. There was no operative mortality. All of postoperative morbidities including transient sinus arrhythmia (2), complete atrioventricular block (1), decreased left ventricular function (2), ventricular tachycardia (1), pericarditis (1), and seizure (1) improved on discharge. The mean follow-up was 55.1$\pm$50.2 months (4.0 months${\~}$18.0 years) and there were no recurrences of fistula. There was 1 second operation for aortic root aneurysm, which developed after external patch closure of right coronary fistula. Conclusion: We demonstrated here that coronary fistulas can be cured with excellent clinical outcome and low operative risk under precise diagnosis. Understanding the anatomic diversity will help to construct surgical plans.

• Clinical and Experimental Pediatrics
• /
• v.46 no.10
• /
• pp.996-1002
• /
• 2003

Purpose : In Rett syndrome patients, the incidence of sudden death is greater than that of the general population, and cardiac electrical instability including fatal cardiac arrhythmia is a main suspected cause. In this study, we are going to find out the possible cause of the higher risk of sudden death in Rett patients by the evaluation of heart rate variability, a marker of cardiac autonomic activity and corrected QT intervals. Methods : Diagnosis of Rett syndrome was made by molecular genetic study of Rett syndrome (MECP2 gene) or clinical diagnostic criteria of Rett syndrome. Heart rate variability and corrected QT intervals were measured by 24 h-Holter study in 12 Rett patients, and in 30 age-matched healthy children with chief complaints of chest pain or suspected heart murmurs. The were compared with the normal age-matched control. Results : Patients with total Rett syndrome, classic Rett syndrome, and Rett variants had significantly lower heart rate variability(especially rMSSD)(P<0.05) and longer corrected QT intervals than age-matched healthy children(P<0.05). Sympathovagal balance expressed by the ratio of high to low frequency(LF/HF ratio) also showed statistically significant differences between the three groups considered(P<0.05). Conclusion : A significant reduction of heart rate variability, a marker of autonomic disarray, suggests a possible explanation of cardiac dysfunction in sudden death associated with Rett syndrome.

• Tuberculosis and Respiratory Diseases
• /
• v.56 no.4
• /
• pp.364-373
• /
• 2004

Background : Obstructive sleep apnea is a contributory factor of hypertension, arrhythmia, ischemic heart disease and other cardiovascular diseases. However, the pathophysiology underlying this relationship is unclear. Recent reports have shown that the soluble intercellular adhesion molecule-1(sICAM-1) and vascular endothelial growth factor(VEGF) are involved in the initiation and progression of atherosclerosis, and some reports state that increased levels of these cytokines are found in patients with obstructive sleep apnea. In this study, the levels of sICAM-1 and VEGF were measured in patients with obstructive sleep apnea in order to determine if obstructive sleep apnea is involved in the pathophysiology of cardiovascular diseases. Methods : Thirty-seven patients were chosen amongst a population who visited the Sleep Disorders Clinic of St. Paul's Hospital in Seoul, Korea for a diagnosis of obstructive sleep apnea and who had subsequently undergone an overnight polysomnography at the clinic. The sera from these patients were retrieved after an overnight polysomnography session and the samples were kept at $-70^{\circ}C$. The cytokine levels were determined with ELISA and the relationships between the serum levels of sICAM-1 and VEGF along with polysomnography parameters were analyzed. Results : No statistically significant correlation was observed between the sICAM-1 levels and the apnea-hypopnea index(r=0.27, P>0.05). Positive correlations were found between the apnea-hypopnea index and serum VEGF levels (r=0.50, P<0.01), the apnea index and the serum sICAM-1 levels (r=0.31, P<0.01), and the apnea index and the serum VEGF levels (r=0.45, P<0.01). Conclusions : Obstructive apnea or hypopnea leads to an increase in the sICAM-1 and VEGF levels. Such an increase in the cytokine levels most likely leads to the higher incidence of cardiovascular diseases observed in patients with obstructive sleep apnea.