• Journal of Biomedical Engineering Research
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• v.19 no.6
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• pp.571-575
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• 1998

One of the most significant features of diagnostic ultrasonic instruments is to provide real time information of the soft tissues movements. Echocardiogram has been widely used for diagnosis of heart diseases since it is able to show real time images of heart valves and walls. However, the currently used ultrasonic images are deteriorated due to presence of speckle noises and image dropout. Therefore, it is very important to develop a new technique which can enhance ultrasonic images. In this study, a technique which extracts enhanced binary images in echocardiograms was proposed. For this purpose, a digital moving image file was made from analog echocardiogram, then it was stored as 8-bit gray-level for each frame. For an efficient image processing, the region containing the heat septum and tricuspid valve was selected as the region of interest(ROI). Image enhancement filters and morphology filters were used to reduce speckle noises in the images. The proposed procedure in this paper resulted in binary images with enhanced contour compared to those form the conventional threshold technique and original image processing technique which can be further implemented for the quantitative analysis of the left ventricular wall motion in echocardiogram by easy detection of the heart wall contours.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.4
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• pp.200-204
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• 2006

Purpose: Determination of pulmonary to systemic blood flow ratio (QP/QS) is important for the management of patients with left-to-right shunt. This study was performed to assess the agreement of Qp/Qs ratio using the radionuclide method and oxymetry, to investigate the factors influencing the agreement, and to know how interchangeable the results of each technique. Materials and Methods: We compared the Qp/Qs measured by single-pass radionuclide angiocardiography and oxymetry during catheterization in 207 patients who underwent both studies. In radionuclide method, Qp/Qs was calculated from the pulmonary time-activity curves using a gamma variate fit. The correlation and Bland-Altman analysis were performed according to the levels of shunt and associated lesions. Results: The mean Qp/Qs was $1.83{\pm}0.50$ by radionuclide, and $1.74{\pm}0.51$ by oxymetry. The overall correlation coefficient was 0.86(p<0.001), and Bland-Altman range of agreement encompassing 4SD was 1.05. For atrial septal defect, ventricular septal defect, patent ductus arteriosus, tricuspid and mitral insufficiency, the correlation coefficient was 0.78, 0.90, 0.84, 0.63 and 0.44, and Bland-Altman range was 1.51, 0.74, 0.96, 1.57, and 1.50, respectively. Conclusion: There is good agreement but wide variance between the Qp/Qs ratios by radionuclide method and oxymetry. Associated atrioventricular valvar insufficiency decreases the correlation coefficient and widens the variance. Wide overall variance suggests that Qp/Qs measurements by two techniques should not be used interchangeably.

• Journal of Chest Surgery
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• v.16 no.2
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• pp.139-146
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• 1983

Between 1974 and 1982, 31 patients from 7 to 15 years of age have undergone valve replacement for their acuqired cardiac valvular diseases at Seoul National University Hospital. Furteen patients (45.2%) had a definite history of rheumatic fever and only 4 patients (12.9%) had atrial fibrillation on their preoperative electrocardiograms. Characteristically, the valvular lesions were ones of insufficiency with or without associated stenosis in all patients except only one whose mitral valve was tightly stenotic. Thrity-seven valves were replaced in 31 patietns including a case of successful replacement of his failed xenogragt mitral valve : 4 mechanical valves were used in 3 patients and 33 xenograft valves were used in the remaining 28 patients. The size of the valves were not the major problem at the time of opertion because most of the patients had a dilated heart from disease. There were 3 diaths within 30 days of surgery (9.7% operative mortality rate) and 3 late deaths (9.7% late mortality rate) with an overall mortality rate of 19.4%. Twenty-eight early survivors were followed up for a total of 488 patient-months. Thromboembolic complications occurred in 5 patients with 2 deaths: cmbolic rate of 17.9% or the actuarial embolic incidence of 12.29%/patients-year. four xenograft tissue valves in 4 patients had failed during the period from 19 to 41 months of surgery with an overall valve failure rate of xenograft of 14.3% or the actuarial incidence of 9.84% failure/patient-year. One of these 4 patients had required replacement of his failed mitral xenograft valve which had severe calcification and tissue disruption with primary tissue failure rate of 3.6% or the actuarial incidence of 3.13% failure/patient-year. The actuarial survial including the operative morality was 50.0% at 5 years of surgery. /the actuarial incidence free from thromboembolism in bioprosthetic group was 85.4% at 42 months, while it was 33.4% in mechanicial group at 60 months after operation. The actuarial incidence free from overall valve failur of 100.0% until 18 months after surgery was followed by a rapid decrease during the next 2-year period, and it was only 17.8% at the follow-up end of 42 months after surgery. It was suggested that the major advantage of low thrombogenecity with xenograft valve should be balanced against the high incidence of accelerated valve failure when it is used in children whose age is younger than 15 years old. The possible role of recurrent rheumatic attacks to the early failure of xenograft tissue valve was also discussed.

• Journal of Chest Surgery
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• v.29 no.11
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• pp.1212-1217
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• 1996

From Dec. 1993 to May 1995, 9 male and 5 female patients ranging in age from 25 to 65 years, were operated on for ascending aorta and/or aortic arch diseases. Six patients had acute aortic dissection, type A(ruptured in 4 cases); four had ruptured ascending aortic aneurysm; three had annuloaortic ectasia(ruptured in 1 cases); one had aortic arch aneurysm. The diagnostic procedures were echo cardiography and dynamic CT scan in all patients having acute dissection or rupture. The aortic angiography was performed in two cases. Indications for operations were rupture in five cases, acute aortic dissection in five cases, severe congestive heart failure in two cases, progressive aortic insufficiency in one case and impending rupture in one case. The emergent repair was performed in ten cases(71%). The surgical treatment consisted of 6 Cabrol operations, a Cabrol operation combined with arch replacement, a modified Bentall operation, 4 replacement of ascending aorta, a replacement of aortic arch, and a replacement of ascending aorta and aortic arch. Complications were a hypoxic encephalopathy, two atrial fibrillations, a sternal deheiscence, and a mediastinitis. Two early mortality(14%) were due to intractable bleeding and multiple organ failure, and one late mortality(7%) was due to ventricular arrhythmia. In eleven survivors, follow-up period was from 2 months to 12 months and the course was uneventful.

• Journal of the Korean Society of Radiology
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• v.81 no.2
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• pp.324-336
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• 2020

Cardiovascular calcifications can occur in various cardiovascular diseases and can serve as a biomarker for cardiovascular event prediction. Advances in CT have enabled evaluation of calcifications in cardiovascular structures not only on ECG-gated CT but also on non-ECG-gated CT. Therefore, many studies have been conducted on the clinical relevance of cardiovascular calcifications in patients. In this study, we divided cardiovascular calcifications into three classes, i.e., coronary artery, thoracic aorta, and cardiac valve calcifications, which are closely associated with cardiovascular events. Further, we briefly described pericardial calcifications, which can be found incidentally. Since the start of lung cancer screening in Korea in the second half of 2019, the number of non-enhanced, non-ECG-gated, low-dose chest CT has been increasing, and the number of incidentally found cardiovascular calcifications has also been increasing. Therefore, understanding the relevance of cardiovascular calcifications on non-enhanced, non-ECG-gated, low-dose chest CT and their proper reporting are important for radiologists.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.142-149
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• 2003

To know the feasibility of the coronary artery bypass graft (CABG) for multivessel coronary artery disease with purely bilateral internal thoracic arteries (ITAs), we analyzed the short-term clinical results and the coronary angiography of the patients. Material and Method: From March 2001 to June 2002, four hundred and five patients underwent CABG. Purely bilateral ITAs were used in 159 patients (39.3%). We analyzed these patients retrospectively The mean age of these patients was $61.2{\pm}8.5$ (range: 30 ~80) years and there were 123 male patients. The preoperative risk factors were as follows: diabetes in 54 patients (34.0%), history of acute myocardiac infarction within 4 weeks in 29 (18.2%), and emergency operation in 6 (3.8%). Off-pump CABG was carried out in 128 patients (80.5%). Associated procedures were mitral valvuloplasty (5), aortic valve replacement (3), Dor procedure (1), and so on. Result: The mean number of distal anastomoses was $3.1{\pm}0.9$ (range: 2~6), the mean duration of hospital stay was $8.4{\pm}4.5$ days. There was one (0.6%) operative death. Except for one early death, no other patients suffered from low cardiac output. The other postoperative complications were occurred as follows: reoperation due to bleeding in 3 patients, perioperative myocardiac infarction in 1, transient cardiac arrest in 2, transient cognitive dysfunction in 7, and transient ischemic attack in 1, and deep sternal wound infection in 1 patient. Recently, early postoperative angiography was performed in 19 patients who had triple vessel disease. The total number of distal anastomosis was 78 (mean $4.1{\pm}0.8$/patient). All distal anastomosis sites were patent, but competition flow was observed at the bypass sites where the native coronary artery stenosis was not significant. Conclusion: The CABG with purely bilateral ITAs for triple vessel disease was performed safely. The early patency rate was relatively good in small number of patients. However the long-term patency rate and the functional study to evaluate the sites where competition flow was observed should be followed.

• Journal of Chest Surgery
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• v.31 no.11
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• pp.1043-1048
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• 1998

Background: As coronary arterial disease is increasing, we evaluated the patients who underwent CABG(Coronary Artery Bypass Grafting) and thus report the early results and risk factors related to mortality and morbidity. Materials and methods: Between July 1996 and February 1998, 42 patients underwent CABG. We analyzed age, sex, preoperative ejection fraction, Canadian heart classification, prevalence factors of CAD(Coronary Artery Disease), angiographic findings, graft vessel numbers, IMA(Internal Mallary Artery) use, ECC* (extracorporeal circulation) time and morbidity. We also evaluated the mortality rate and the causes of death. Results: Complication was developed at 17cases. The average age of the complication group was 61±11.9 years and that of the noncomplication group was 51±10.5 years(p=0.004). ECC time was 198±42.5(min) in the complication group and 158±47.4(min) in the noncomplication group(p=0.008). The other factors had no correlation to the morbidity, statistically. The average follow up duration was 12.5 months and all the patients were alive except for the 2 expired cases. The mortality rate was 4.7%, among which one patient who underwent CABG with aortic valve replacement died due to multiorgan failure and the other died due to sepsis with pneumonia and wound infection. Conclusions: We conclude that the risk factors related to morbidity were age and ECC time, and that there were no correlations between other factors and morbidity.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.626-632
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• 2006

Background: Pulmonary hypertension caused by chronic pulmonary embolism is underrecognized and carries a poor prognosis. Medical therapy is generally unsatisfactory and palliative. With the improvement of operative technique and postoperative management, pulmonary endarterectomy has been the treatment of choice for this condition. Material and Method: Between January 2001 and December 2005, eleven patients were received pulmonary endarterectomy. All patients had chronic dyspnea and exercise intolerance. Diagnosis was made with cardiac echocardiography, lung perfusion scan and computed tomography. Before the operation, Greenfield vena cava filter were placed in all patient except one. Deep hypothermic circulatory arrest was used for the distal-most portion of the endarterectomy procedure. More than moderate degree of tricuspid reguirgitation was repaired during operation. Result: There was no early and late death. Right ventricular systolic pressure was reduced significantly after operation from $91{\pm}21$ mmHg to $40{\pm}17$ mmHg on echocardiography (p=0.001). NYHA class and tricuspid reguirgitaion were improved postoperatively. Although mild reperfusion injury in three case and postoperative delirium in one case were observed, all of them recovered without complication. Conclusion: Pulmonary thromboendarterctomy offers to patient an acceptable morbidity rate and anticipation of clinical improvement. This method is safe and effective operation for pulmonary hypertension caused by chronic pulmonary thromboembolism.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.9-13
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• 2009

Background: Hypoplastic left heart syndrome is uniformly fatal if this condition is not properly treated. We reviewed the surgical results of treating hypoplastic left heart syndrome, and we evaluated the hemodynamics and functional status of these patients after they underwent a Fontan operation. Material and Method: To assess the surgical results, we retrospectively reviewed the medical records of 6 (M/F=4/2) patients who underwent a staged operation, including a Norwood procedure, a bidirectional Glenn procedure and a Fontan procedure between October 1997 to May 2005. The mean age of the patients was $17.3{\pm}10.8$ days (range: 9~36 days) at the $1^{st}$ staged operation, $8.9{\pm}7.1$ months (4.6~23.3 months) at the $2^{nd}$ staged operation (the Bidirectional Glenn procedure) and $32.4{\pm}9.8$ months at the final staged operation (the Fontan procedure). During the $2^{nd}$ staged operation, one of the patients received tricuspid valve repair due to regurgitation. All the patients underwent an extracardiac Fontan procedure using Gore-Tex conduit (20 mm: 2 patients, 18 mm: 4 patients) and one of them required fenestration. Result: 21 patients underwented a Norwood procedure. There were 7 early deaths and 4 interstage deaths. Bidirectional cavopulmonary shunt was performed in 10 patients and the Fontan procedure was done in 6 (mortality: 1 patient, Flow up loss: 1 patient, Awaiting a Fontan procedure: 2 patients). After the Fontan procedure, there was no complication except for one case of post operative bleedings. All the patients had good ventricular function and 2 had grade I tricuspid regurgitation, as noted on their echocardiography. The average follow up period after the Fontan procedure was $19.6{\pm}14.9$ months (range: 1.5~39.1 month). All the patients had normal sinus rhythm and they were put on aspirin and cardiac medication. During follow up period, all the patients had a good functional status (NYHA functional class I). Conclusion: All the patients who suffered with hypoplastic left heart syndrome and who underwent a Fontan procedure achieved a good hemodynamic and functional status, even though there was a relatively high operative mortality rate after stage I Norwood palliation. Therefore, thise staged operation should be strongly recommended as an important surgical strategy for treating hypoplastic left heart syndrome.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.383-389
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• 1997

From March, 1992 to March, 1996, a total of 279 patients underwent coronary bypass surgery at the Sejong General Hospital, Puchon. We selected 22 patients with severe left ventricular(LV) dysfunction from them. The criteria were the presence of global or segmental abnormalities of left ventricular contraction and LV ejection fraction(EF) less than 35% based on biplane LV angiography by planimetry method. The mean age of 17 male and 5 female patients was 60$\pm$5.6years(range:47~73 years). All had the anginas, which were Canadian class II in 6, class 111 in 12 and class IV in 4. All patients except one had the history of previous myocardial infarction more than once. Seven of them had the symptoms and signs of congestive heart failure, such as dyspnea on excertion and increased pulmonary vascular markings. Their mean LVEF was 29.4$\pm$4 5%(range : 18~35%) and mean LV end-diastolic pressure was 18.7 $\pm$8. 2mmHg(range:10~42mmHg). 21 patients had 3 vessel-disease and 1 had 2 vessel-disease. Complete revascularization was tried with the use of 16 internal mammary arteries and 60 sapheuous veins and 3 radial arteries grafts. The mean number of distal anastomosis was 3.5$\pm$ 1.1. Concomitantly, one mitral valvuloplasty and annuloplasty was performed in the patient with moderate mitral regurtigation. The hospital mortality was 4.5%. During the follow-up, there were 3 late deaths. Of 18 survivors, 2 patients were lost in follow-up 24 and 27 month respectively after operation and the remaining 16 patients have bcen followed up with an average of 30.4 $\pm$ 13.4 months.15 patients had improvement with respect to angina but 8 patients still have the continuing or progressing heart failure. The 1-year, 2-year and 3-year actuarial survival rate was 85.2, 69.1, 46.1%, respectively. This study indicates that coronary artery bypass sur ery can be performed in the patients with severe LV dysfunction at acceptable risk but does not greatly contribute to the improvement of congestive heart failure.