• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.10
• /
• pp.893-899
• /
• 2010

A previous study showed that hemodynamics is correlated with stenosis in the coronary artery. The flow characteristics and the distributions of the hemodynamic wall parameters in the coronary artery are investigated under physiological flow condition. The present study also aims to establish the mechanism of the generation of atherosclerosis by analyzing the hemodynamic variables in the coronary artery where atherosclerosis frequently occurs. The stenosis phenomena due to atherosclerosis are related to not only the biochemical reaction between blood and blood vessels but also the hemodynamic factors sush as flow separation and oscillatory wall shear stress. As the bifurcated angle increases, the size of the recirculation area that appears in the cross section increases and disturbed flow is observed in this area. We speculate that this area is the starting point of atherosclerosis in the coronary artery.

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

• Journal of Chest Surgery
• /
• v.38 no.11 s.256
• /
• pp.733-738
• /
• 2005

Background: The possibility of incomplete revascularization and development of flow competition after revascularization of the borderline lesion made the hybrid strategy as an option for complete revascularization. Material and Method: From January f998 to July 2004, 25 $(3.2\%)$ patients underwent hybrid revascularization among 782 total OPCAB procedures. Clinical results and angiographic patencies were evalulated. Percutaneous coronary intervention (PCI) was peformed before CABG in 8 patients and after CABG in 47 patients. Result: The causes of PCIs before CABG were to achieve complete revascularization with minimally invasive surgery (n=7) and emergent PCI for culprit lesion (n=1). The indications of PCIs after CABG were high possibility of flow competition in the borderline lesion of right coronary artery territory (n=8), diffuse atheromatous lesion preventing anastomosis of graft (n=5), severe calcified ascending aorta with no more arterial grafi available (n=3), and intramyocardial coronary lesion (n=1). Mean number of distal anastomoses was $2.3\pm1.0$. Mean number of lesions treated by PCI was $1.2\pm0.4$. There was no operative or procedure-related mortality. PCI-related complication was periprocedural myocardial infarction in one patient, and complications related to CABG were transient atrial fibrillation (n=5), perioperative myocardial infarction (n=1), and transient renal dysfunction (n=1). Early postoperative coronary angiography $(1.8{pm}1.6days)$ revealed $100\%$ patency rate of grafts (57/57). The stenosis occurred in one patient performed PCI before CABG, which was successfully treated with re-ballooning. During midterm follow-up (mean; $25{\pm}26$ months), 1 patient died of congestive heart failure. All survivors (n=24) accomplished follow-up coronary angiographics, which showed .all grafts (56/57) were patent except one string sign. In-stent restenosis was developed in 2 patients who received bare metal stents. Conclusion: In selected patients, complete revascularization was achieved with low risk by taking the hybrid strategy.

• Journal of Chest Surgery
• /
• v.37 no.11
• /
• pp.925-928
• /
• 2004

Bilateral coronary artery to pulmonary artery fistulas are very rare anomaly. Echocardiography, cardiac catheterization and coronary angiography of two patients having chest pain and dyspnea showed bilateral coronary to pulmonary artery fistulas. One patient had left anterior descending coronary artery stenosis and the other patient had cystic tumor. We report the good results of the surgical treatment of two patients with bilateral coronary to pulmonary artery fistulas.

• The Korean Journal of Nuclear Medicine
• /
• v.37 no.3
• /
• pp.153-161
• /
• 2003

Purpose: Recently the occurrence of dipyridamole stress-induced short term stunning was proven and it is reported that Bland Altman analysis by repeated acquisition Tl-201 gated myocardial SPECT (gSPECT) revealed the 95% limit of agreement for LVEF was 10.3 %. The purpose of this study was to investigate the clinical value of dipyridamole induced transient LV dysfunction on Tl-201 gSPECT. Materials and Methods: Total 93 patients were included and coronary angiography was peformed in all patients less than 2 month from gSPECT. The patients with myocardial infarction were excluded. All patients underwent both dipyridamole stress and 4-h redistribution Tl-201 gSPECT. Forty nine patients of total 93 showed normal coronary arteries (Group 1) and the remaining 44 patients had coronary artery disease (Group 2). We compared LV EF, EDV and ESV during post-stress and 4-h redistribution period calculated by gSPECT using quantitative gated SPECT software and the incidence of dipyridamole induced transient LV dysfunction between group 1 and 2. The criteria for transient LV dysfunction was defined more decrease ${\geq}11%$ of LVEF during post-stress than 4-h redistribution according to previous reported Bland Altman analysis. Results: During post-stress and 4-h redistribution average of 3.1% increment in LVEF, 6.6% increment in LVEDV and 0.7% decrement in LVESV were shown after stress in Group 1, whereas 4.1% decrement, 9.7% increment and 7.2% increment in Group 2 respectively. Dipyridamole induced transient LV dysfunction was only detected in group 2 (18.2%) and not in group 1. It was more frequently observed in triple vessel disease and left main disease (31.8%, N=22) than one and two vessel disease (4.5%, N=22). Conclusion: As with Tc-99m myocardial agent post-stress LV dysfunction was observed in dipyridamole Tl-201 gSPECT. It was only detected in CAD and more frequently occurred in multivessel disease. Thus this finding seems to provide additional information in the diagnosis of coronary artery disease and prediction of prognosis.

• Journal of The Korean Radiological Technologist Association
• /
• v.28 no.1
• /
• pp.341-341
• /
• 2002

• Journal of Chest Surgery
• /
• v.34 no.9
• /
• pp.692-697
• /
• 2001

Background: The left main coronary artery surgical angioplasty has become the choice of surgical procedure in isolated LM disease. We have performed 22 cases of LMCA surgical angioplasy since 1996. We report the immediate and long term result of the surgical angioplasty with their postoperative angiography. Material and Method: Between July 1994 and October 2000, 22 patients(11 men and 11 women) were subjected to surgical patch angioplasty of the LMCA, 1 patient had an additional angioplasty performed on the proximal right coronary artery. The LMCA was approached anteriorly with or without transection of the main pulmonary artery(21 cases), and in a patient who had undergone an aortic valve replacement, LMCA was approached superiorly with transection of the ascending aorta. Additional grafting was required in 5 cases. The on-lay patch was used with autologous pericardium in 6 cases and bovine pericardium in 16 cases. Result: There was no operative mortality. There was 30~50% stenosis of the anastomosis site in 3 cases at the postop. coronary angiography. Coronary angiography was reperformed in 5 cases between 5th months and 15th months postoperatively. There was 40~60% stenosis of the anastomosis site in 2 cases. There was one death at 42nd months postoperatively but the cause was unknown. No patient complained of angina with a mean follow up of 48.$\pm$22.5 months. Conclusion: There were only several coronary angiographic results in long term follow-up but we had relatively good clinical results for LMCA surgical angioplasty in the immediate and long term. The excellence of LMCA surgical angioplasty needs the result of the long term follow-up.

• Journal of radiological science and technology
• /
• v.33 no.1
• /
• pp.37-44
• /
• 2010

We sought to confirm an independent factor about in-stent restenosis (ISR) in the patients who underwent drug-eluting stent (DES) and know a possibility as a predictor of measured coronary artery calcium score by MDCT. A total of 178 patients (159 men, $61.7{\pm}10.0$ years of age) with 190 coronary artery lesions were included in this study out of 1,131 patients who underwent percutaneous coronary intervention (PCI) with DES implantation for significant stenosis on MDCT at Chonnam National University Hospital between May 2006 and May 2009. All lesions were divided into two groups with the presence of ISR : group I (re ISR, N = 57) and group II (no ISR, N = 133). Compared to group II, group I was more likely to be older ($65.8{\pm}9.0$ vs. $60.2{\pm}9.9$ years, p = 0.0001), diabetic (21.8% vs. 52.6%, p = 0.0001), have old myocardial infarction (8.8% vs. 2.3%, p = 0.040), left main stem disease (5.3% vs. 0.8%, p = 0.047), and smaller stent size ($3.1{\pm}0.3\;mm$ vs. $3.3{\pm}0.4\;mm$, p = 0.004). Group II was more likely to be smokers (19.3% vs. 42.1%, p = 0.003), have dyslipidemia (8.8% vs. 23.3%, p = 0.019). Left ventricular ejection fraction, lesion complexity, and stent length were not different between the two groups. Total CAC score was $389.3{\pm}458.3$ in group I and $371.2{\pm}500.8$ in group II (p = 0.185). No statistical difference was observed between the groups in CAC score in the culprit vessel, left main stem, left anterior descending artery, left circumflex artery, and right coronary artery. On multivariate logistic regression analysis, left main stem disease (OR = 168.0, 95% CI = 7.83-3,604.3, p = 0.001), male sex (OR = 36.5, 95% CI = 5.89-2,226.9, p = 0.0001), and the presence of diabetes (OR = 2.62, 95% CI = 1.071-6.450, p = 0.035) were independent predictors of ISR after DES implantation. In patients who underwent DES implantation for significant coronary stenosis on MDCT, ISR was associated with left main stem disease, male sex, and the presence of diabetes. However, CAC score by MDCT was not a predictor of ISR in this study population.

• Journal of Chest Surgery
• /
• v.31 no.2
• /
• pp.118-124
• /
• 1998

Minimally invasive coronary artery bypass grafting without using cardiopulmonary bypass (CPB) is a recently accepted modality of myocardial revascularization prcedures which is particularly suitable to the patients with lesions in the left anterior descending(LAD) and the right coronary arteries. Of the consecutive 35 patients of coronary artery bypass grafting performed at Sejong General Hospital from March to August 1996, six patients underwent minimally invasive coronary artery bypass grafting without CPB. All had stenotic lesions of the LAD more than 90%. Bypass grafting of the LAD was approached through midline sternotomy in one, through ministernotomy in two, and through limited left anterior thoracotomy in three patients, respectively. The internal mammary arteries were prepared without the use of thoracoscope. The mobilized mammary arteries were connected directly to the LAD in 5 patients, and the anastomosis required interposition of a segment of the radial artery in the remaining one. The diagonal branch was revascularized with the saphenous vein graft at the same time in one patient. No blood transfusion was necessary in 2 patients, and average blood required during surgery was 800ml in 4 patients. All patients were extubated from 4 to 14 hours(mean 9 hours) after operation. Early postoperative coronary angiography in 5 patients between 7 and 10 days after surgery has proved full patency of the grafts. With these limited clinical experiences, the clinical results demonstrated that minimally invasive coronary artery bypass grafting without CPB is an useful procedure especially in patients with isolated lesion in the proximal LAD.

• Journal of the Korean Society of Radiology
• /
• v.6 no.4
• /
• pp.275-279
• /
• 2012

Methods and results : The suspected patient who have results of CTA and CAG examinations to evaluate coronary stenose to undergo each 16MD CT(n=93) and dual source CT(n=100). As a results of statistic, the highest rank of sensitivity, specificity, PPV, NPV and accuracy in coronary artery with using 16MDCT was displayed in LAD(73.5%), RCA(74.5%), LAD(66.7%), LCX(75%), LCX(67.7%). The mean diagnostic accuracy of dual source CT was more 17% than 16MDCT. Dual source CT was recorded 84% mean of accuracy. In addition to, segments of coronary artery did not show significant differences in all of them. However, distal segment become more and more accurate than proximal site.