• The Korean Journal of Physiology and Pharmacology
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• v.23 no.1
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• pp.71-79
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• 2019

Body surface potential map, an electric potential distribution on the body torso surface, enables us to infer the electrical activities of the heart. Therefore, observing electric potential projected to the torso surface can be highly useful for diagnosing heart diseases such as coronary occlusion. The BSPM for the heart of a patient show a higher level of sensitivity than 12-lead ECG. Relevant research has been mostly based on clinical statistics obtained from patients, and, therefore, a simulation for a variety of pathological phenomena of the heart is required. In this study, by using computer simulation, a body surface potential map was implemented according to various occlusion locations (distal, mid, proximal occlusion) in the left anterior descending coronary artery. Electrophysiological characteristics of the body surface during the ST segment period were observed and analyzed based on an ST isointegral map. We developed an integrated system that takes into account the cellular to organ levels, and performed simulation regarding the electrophysiological phenomena of the heart that occur during the first 5 minutes (stage 1) and 10 minutes (stage 2) after commencement of coronary occlusion. Subsequently, we calculated the bipolar angle and amplitude of the ST isointegral map, and observed the correlation between the relevant characteristics and the location of coronary occlusion. In the result, in the ventricle model during the stage 1, a wider area of ischemia led to counterclockwise rotation of the bipolar angle; and, during the stage 2, the amplitude increased when the ischemia area exceeded a certain size.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1190-1196
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• 1997

Between July 1994 and August 1995, 78 patients underwent coronary artery bypass graft at Seoul National University Hospital. Coronary angiogram was performed one year after coronary artery bypass graft in 49 patients(62.8%) for evaluation of the graft patency and analysis of the risk factors for graft occlusion. The patency rates of both the internal mammary artery and the radial artery grafts were 100% , although three internal mammary artery grafts(5.0%) were narrowed(string sign). And that of the saphenous vein grafts were 85.2%. Multivariate analysis for the preoperative, operative, and postoperative factors was done between the widely patent and the narrowed internal mammary artery graft groups, and between the patent and the occluded saphenous vein graft groups by the general linear models procedure. Patient's age($\geq$60 years), postoperative intraaortic balloon pump insertion, bleeding, and acute renal failure were found to be the significant risk factors for internal mammary artery graft narrowing, and coronary artery size(< 1.5 mm) was the significant risk factor for the saphenous vein graft occlusion (p<0.05) . This study confirms that the arterial graft is superior to the vein graft at one-year patency rate, and suggests the risk factors for graft occlusion during the first postoperative year. Knowledge of this study may provide a basis for estimating the risk factors for graft occlusion, and thereby modifying surgical strategy and postoperative surveillance.

• Journal of Chest Surgery
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• v.40 no.6 s.275
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• pp.445-447
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• 2007

Occlusion of a coronary artery ostium and especially occlusion of the right by an aortic cusp is a rare condition. We experienced an adult patient with occlusion of the right coronary ostium that was due to fusion of the right coronary cusp to the aortic wall along with underlying rheumatic aortic valve stenosis. During the operation, the adherent right coronary cusp was excised. After confirming that the right coronary ostium was patent, the other cusps were removed, and this followed by replacement of the aortic valve with a mechanical valve. The postoperative course was uneventful.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.251-252
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• 2008

• Journal of Chest Surgery
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• v.37 no.7
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• pp.570-577
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• 2004

CT angiography is now available to evaluate the early graft patency after coronary bypass surgery. We investigated whether patency or occlusion of the bypass grafts can be visualized by CT angiography and what factors effect the visuality. Material and Method: Fifty patients underwent scanning with a 4-slice computed tomographic scanner (Somatom Volume ZoomTM; Siemens, Germany) before being discharged after coronary artery bypass grafting. To evaluate graft patency and relationship between the quality of graft image and the characteristics of the diseased coronary vessels, 50 internal thoracic artery grafts, 18 radial artery grafts, and 56 vein grafts were included in this study. Result: All vein grafts (24 grafts; 32 anastomoses) to left coronary artery system were well visualized, but 3 grafts (4.7%) of 30 vein grafts (35 anastomoses) to right coronary artery system were not visualized. The latter was also occluded in invasive coronary angiographic study. Thirty-nine (78%) internal thoracic artery grafts were well visualized, 8 (16%) faintly visualized, and 3 (6%) not visualized, but all the internal artery grafts were well patent in invasive coronary angiographic study. Conclusion: Unvisualized vein grafts in CT angiography means occlusion of the grafts, but unvisualized arterial grafts in CT angiography may not mean occlusion of the graft but result from competitive flow between the graft and coronary artery. To confirm patency of the unvisualized arterial grafts, invasive coronary angiography is needed.

• Journal of Chest Surgery
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• v.45 no.1
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• pp.45-48
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• 2012

We report a case of a postinfarction ventricular septal defect caused by an acute recurrent occlusion after the implantation of a covered stent, which was performed as a rescue procedure for the ruptured left anterior descending artery during a percutaneous coronary intervention. Although the emergent implantation of a covered stent for the ruptured coronary arteries such as the left main coronary artery or the origins of the left anterior descending artery can be performed during a percutaneous coronary intervention, and a coronary bypass surgery should be considered in order to decrease the risk of complete occlusion, thus providing a superior long term patency.

• International Journal of Vascular Biomedical Engineering
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• v.1 no.2
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• pp.20-29
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• 2003

A new treatment for coronary artery occlusive disease is being developed in which a shunt or conduit is placed directly connecting the left ventricle with the diseased artery at a point distal to the obstruction. To aid in assessing and optimizing its benefit, a computational model of the cardiovascular system was developed and used to explore various design conditions. Simulation results indicate that in complete LAD occlusion, flow can be returned to approximately 65% of normal if the conduit resistance is equal for forward and reverse flow, increasing to 80% in the limit in which backflow resistance is infinite. Increases in flow rate produced by asymmetric flow resistance are considerably enhanced in the case of a partial LAD obstruction since the primary effect of resistance asymmetry is to prevent leakage back into the ventricle("steal") during diastole. Increased arterial compliance has little effect on net flow with a symmetric shunt, but leads to considerable augmentation when the resistance is asymmetric. These results suggest that an LV-LAD conduit will be beneficial when stenosis resistance(Rst) > 27 PRU if resistance is symmetric.

• Journal of Chest Surgery
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• v.23 no.3
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• pp.514-521
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• 1990

Patient with aortic valvular disease have increased left ventricular work and greater myocardial oxygen demand, which may aggravate the effect of concomitant coronary artery disease. Thus in patient who repair aortic valve replacement, concomitant aortocoronary bypass surgery is often performed when angiographically significant coronary artery disease is present. This approach is supported by reports that revascularization does not increase operative risk when associated coronary artery disease is present and significantly reduce the occurrence of late sudden death. Recently we have experienced one case of aortic valve replacement concomitant with aorta-coronary bypass surgery. The patient was 56 year-old male and admitted with complaint of anterior chest pain especially during his exercise. He was diagnosed as aortic valve stenosis and regurgitation [GIII] with proximal right main coronary artery occlusion We performed aortic valve replacement with aorta coronary bypass surgery by use of saphenous vein. Post operative course was uneventful and chest pain was relieved. Post operative coronary angiogram disclosed good patency of grafted vessel.

• Journal of Chest Surgery
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• v.33 no.2
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• pp.167-172
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• 2000

Background: As the internal mammary artery is far superior to the vein in the patency rate recently there has been a tendency to use the arterial graft as much as possible in coronary artery bypass grafts with the expectation of better the short- and long-term patency rate. Material and Method: We sequentially grafted the diagonal and the left anterior descending artery significantly influencing the cardiac function with the internal mammary artery. There were 32 cases of sequential grafts from July 1993 to December 1998: 21 men and 11 women. The age range was from 43 to 69 years with a mean age of 56.64$\pm$6.41 years. There were 22 unstable angina 7 stable angina and 3 acute myocardial infarction. 8 cases of them were accompanied by stenosis of the left main coronary artery. The grafts for coronary artery bypass surgery included the great saphenous vein at 60 the right gastroepiploci artery at 5 and the left internal mammary artery at 64 coronary arteries. Result: One patient died from sepsis and multiorgan failure. Complications included wound infections in two cases and gastrointestinal bleeding in one patient. All patients showed decrease or disappearance of angina after operation. The postoperative coronary angiogram performed in 9 patients showed neither occlusion nor stenosis of the grafts. Conclusion: This study suggests that sequential anastomosis of the internal mammary artery to the diagonal and the left anterior descending artery may result in excellent short-term patency diagonal and the left anterior descending artery may result in excellent short-term patency rate and be useful for the coronary artery bypass graft using only arterial grafts

• Journal of Chest Surgery
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• v.34 no.6
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• pp.499-501
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• 2001

In the 1970s, the radial artery was proposed as a coronary artery bypass graft but then was abandoned due to graft occlusion secondary to spasm during harvesting. Development of new pharmacologic antispasmodic agents and minimal traumatic harvesting techniques has led to the revival of the use of the radial artery in coronary artery bypass procedures. Harmonic Scalpel(Ultracision Inc, Smithfield, Rl) offers the surgeon the ability to perform less traumatic, spasm free, and rapid radial artery harvesting.