• Journal of Chest Surgery
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• v.32 no.8
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• pp.715-721
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• 1999

Background:The number of old patients receiving coronary artery bypass grafting(CABG) is increasing. With the more recent advances in operative techniques, the age at which CABG is indicated has also increased. This study evaluated the risk factors associated with the hospital mortality and the morbidity following CABG in elderly patients. Material and Method: Between March 1991 and June 1998, we retrospectively reviewed 45 consecutive patients aged 65 years or older who underwent CABG. We compared the data with the results of 179 patients under the age 65 years operated during the same period. Result: Mean age was 68${\pm}$1.41 years(range 65 to 74 years). Emergency surgery was required in 4, and elective surgery in 41 patients. The mean number of distal anastomosis per patient was 3.62 ${\pm}$0.81 and mean aortic cross-cramp time was 69.84${\pm}$18.5 minutes. Thirty patients had Canadian class III or IV preoperatively, but 43 patients had class I or II postoperatively. The left ventricular ejection fraction increased significantly from 54.23${\pm}$10.62% preoperatively to 58.14${\pm}$9.88% postoperatively(p<0.05). Postoperative complication was pneumonia in 2 patients, acute renal failure in 2 patients, sternal wound infection in 1 patient, and postoperative myocardial infarction in 1 patient. There were two postoperative deaths. The causes of deaths were low output syndrome in one patient, and sepsis due to pneumonia in the other patient. The hospital mortality was higher in the elderly group(4.4 versus 2.86%) but was not statistically significant(p>0.05). Incremental risk factors for hospital deaths in the elderly were emergent operation, preoperative PTCA, postoperative use of IABP and postoperative ARF(p<0.05). The duration of hospital stay after operation was significantly longer for the elderly group than the younger group(19.27${\pm}$12.51 vs 15.55${\pm}$6.99 days; p＜ 0.05). Follow-up was complete for 34 of the hospital survivors and ranged from 1 to 73 months(mean: 23.58${\pm}$19.56 months). There was no late mortality of cardiac origin. Conclusion: Age is an important factor in selecting optimal management for elderly patients with coronary compromise, but age alone should not dictate the choice of therapy. Coronary artery bypass surgery in the elderly is associated with acceptable early mortality and excellent long-term results.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.861-866
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• 1996

Surgical angioplasty of isolated stenosis of the left main coronary artery(LMCA) restores a more physiologic flow to the myocardium, allows percutdneous transluminal coronary angioplasty (PTCA) of distal coronary stenoses at a later stage, and is a less time consuming and convenient procedure than the conventional coronary artery bypass grafting(CABG) . Between Jul. 1994 and Dec. 1995, 7 surgical angioplasty had been performed. LMCA stenoses involved ostium in 2 patients, middle third in 3, and dis- tal third in 2. In 2 patients, the origin of left anterior descending coronary artery was involved in conjunction with LMCA. T e additional coronary artery stenoses were found in 2 cases. One patient was emergently operated after coronary angiography following his cardiac arrest. LMCA was approached anteriorly in all patients. The pulmonary artery was transected in 3 patients for a better exposure. The onlay patch consisted or autologous or bovine pericardium. There was no postoperative myocardial infarction or mortality. Left ventricular functions were well preserved in all patients. Postoperative coronary angiography revealed widely patent LMCA in 5 cases, and mild narrowing of distal anastomotic sites in 2 cases. Provided that well defined indications are followed correctly, surgical angioplasty can be a safe alternative to conventional CABG.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.210-217
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• 1993

To compare the myocardial viability in patients suffering from total occlusion of the right coronry artery (RCA) with the angiographic collaterals, intracoronary injection of Thallium-201 (T1-201) was done to 14 coronary artery disease (CAD) patients (pts) with total occlusion of RCA and into four normal subjects for control. All 14 CAD pts had Grade 2 or 3 collateral circulations. There were 14 male and 4 females, and their ages ranged from 31 to 70 years. In nine pts, T1-201 was injected into left main coronary artery (LCA) ($300{\sim}350{\mu}Ci$) to evaluate the myocardial viability of RCA territory through collateral circulations. The remaining five pts received T1-201 into RCA ($200{\sim}250{\mu}Ci$) because two had intraarterial bridging collaterals and three had previous successful PTCA. Planar & SPECT myocardial perfusion images were obtained 30 minutes, and four to five hours after T1-201 injection. Intravenous T1-201 reinjection (six pts) or $^{99m}Tc-MIBI$ (two pts) were also performed in eight CAD pts. Intracoronary myocardial perfusion images were compared with intravenous T1-201 (IV T1-201) images, ECG, and ventriculography. Intracoronary T1-201 images proved to be superior to that of IV T1-201 due to better myocardial to background uptake ratio and more effective in the detection of viable tissue. We also found that perfusion defects were smaller on intracoronary T1-201 images than those on the IV T1-201. All of the 14 CAD pts had either mostly viable myocardium (seven pts) or large area of T1-201 perfusion (seven pts) in RCA territory, however ventriculographic wall motion and ECG did not correlate well with intracoronary myocardial perfusion images. In conclusion, total RCA occlusion patients with well developed collateral circulation had large area of viable myocardial in the corresponding territory.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.191-195
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• 2000

This study was undertaken to estimate the exposed dose of the medical personnel during the intracoronary radiotherapy procedure as a part of ongoing SPARE (Seoul National University Hospital Post-Angioplasty Rhenium) trial. Data of thirty-four patients among forty-two irradiated patients participating in this trial due to coronary artery stenosis were retrospectively analyzed. Intracoronary radiotherapy was delivered to the patient immediately after angioplasty ballooning. Prescribed dose was 17 Gy to media of the diseased artery and was delivered with $^{188}Re$ filled balloon catheter. Dosimetry was carried out with GM counter at eight different points. Ten centimeter and forty centimeter from the patient's heart were selected to represent maximum and whole-body exposed dose of the operator, respectively. Median delivered dose was 111.6 mCi with average treatment time of 576 seconds. Average exposed dose rate at 10 cm and 40 cm from the patient's heart were 0.43 mSv/hr and 0.30 mSv/hr, respectively. Average exposed doses per treatment were 0.07 mSv and 0.05 mSv for 10 cm and 40 cm from the patient's heart, respectively. Exposed doses measured are much lower than recommended limit of 50 mSv for radiation workers or 1 mSv for general population in ICRP-60. This study proves that current method of intracoronary radiotherapy incorporated in this trial is very safe regarding radiation protection.

• Journal of Korean Academy of Nursing
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• v.30 no.3
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• pp.549-559
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• 2000

The purpose of this study was to investigate the correlation between the knowledge and educational needs related to recurrent in coronary artery bypass graft patients as a basis to provide an individual nursing education for the population. The subjects consisted of 110 patients who had coronary artery bypass graft(CABG) at Asan Medical Center in Seoul and Sechong hospital in Buchon. Data was obtained from a knowledge questionnaire and a learning needs questionnaire between November 1998 and February 1999. Data were analyzed using SAS program for Wilcoxon rank sum test and Spearman correlation coefficient. The results were as follows : 1. With regard to the 18 items to measure knowledge, the mean (median) of items 'don't know' was 4.9(4) items. The mean (median) of items answered wrong was 3.2(3) items. The number of items answered 'don't know' tend to show higher in those who had less education, blue color jobs and myocardiac infarction history than in their counter parts. There were higher frequency of items answered 'don't know' in those who had no hypertension 2. With regard to the level of knowledge by questionnaire about CABG, The most "I dont know" (59.1%) highly response was 'He has to be treated with anticoagulant drug to prevent revasculized vessel from obstructing.' The seond highest response (56.4%) was 'If you were hypotensive, the coronary attack would collapse. 'During the hospitalized day, the patient has complete bedrest.' The highest error probability was cholesterol has not to intake.', 'After surgery, the sexual life is need controlled for 1 year. 3. The mean of educational needs was 3.38. With regard to the level of learning needs by sentence about CABG, 'Food that benefit heart disease', 'Recurrence possibility of heart disease', 'Management method of operation site', 'Risk symptom that visit hospital or report immediately' were higher than other sentenses. With regard to the level of learning needs by factor 'food(5 items)', 'disease(9 items)' and 'exercise(3 items)' showed the highest than other factors. The educational needs by patients characteristics tend to show higher in males, under the age of 49, middle or high school degree, previous experience of admission with coronary artery disease, history of myocardial infarction, expierience of PTCA, history of cerebro-vascular accident, previous expierience of smoking than in their counter parts. 4. The number of items answered 'don't know', wrong and correct weren't correlated with the level educational needs. As the results, the number of items answered 'don't know' tend to show higher in those who had less educated, blue color jobs and myocardiac infarction history than in their counter parts. There were higher frequency of items answered 'don't know' in those who had no hypertension .There were higher frequency of items answered 'don't know' on anti-thrombolitic theraphy, hypotension and pain relief. Also there were higher frequency of items answered wrong on bed rest period, cholesterol intake, and sexual life. Educational needs were higher in young age group, had previous experience of procesure and history of other disease. And when we educate CABG patients, education for diet, recurrence possibility of disease, management methods of operation site and risk symptom should be emphasized.

• Progress in Medical Physics
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• v.13 no.2
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• pp.98-103
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• 2002

The purpose of this study was to evaluate the absorbed dose to the coronary artery segment from various sized balloon angio catheters. The liquid form of Ho-166 was produced at the KAERI by (n, ${\gamma}$ ) reaction. We used GafChromic film for the estimation of the absorbed dose by beta particles. The exposed films were read using a videodensitometer. Several film exposures were made with varying irradiation times and activities. A modified micrometer was used for the measurement of the absorbed dose distribution near the balloon surface. Four balloons of coronary catheters evaluated were 30 m long and 2.5, 3.0, 3.5 and 4.0 mm in diameter. All doses are plotted in units of Gy/min/GBq/ml as a function of radial distance in mm from the surface of balloon. The absorbed dose rate was 0.86, 1.01, 1.11 and 1.24 Gy/min/GBq/ml at a balloon surface for various balloon diameter 2.5, 3.0, 3.5 and 4.0 mm respectively. Using a vacuum pump, the air in the balloon was evacuated prior to instillation of the Ho-166 source. By removing air bubbles in the balloon, the absorbed dose distribution was more uniform.

• Progress in Medical Physics
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• v.10 no.3
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• pp.151-157
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• 1999

The GafChromic film was used for the dosimetry of a balloon angio catheter filled with the radioisotope HO-166 for endovascular irradiation. The balloon angio catheter was 2 cm long and 3 mm in diameter when inflated. The isotope, Ho-166, was produced by the neutron bombardment using the research reactor in Korea Atomic Energy Research Insititute. Co-60 teletherapy beam was used for making H-D curve for the Gaf-Chromic film. The film dosimetry was measured with a videodensitometer. The radial dose distribution indicated that the absorbed dose dropped to about 20% of the surface dose at the 1 mm away from the balloon surface and at 5 mm position the dose decreased to below 1% of the surface dose. The result also shows that with the specific activity of Ho-l66, 250 mCi/ml it takes 230 seconds to deliver 1200 cGy to the region where is 1mm away from the balloon surface. The concentric isodose curves were also presented. The Ho-166 is an another alternative for endovascualr irradiation to prevent restenosis after PTCA (Percutaneous Trans Coronary Angioplasty)

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.30-38
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• 2000

Purpose: We investigated the role of myocardial perfusion SPECT in prediction of ventricular dilatation and the role of revascularization including thrombolytic therapy and PTCA in prevention of ventricular dilatation after an acute myocardial infarction (AMI). Materials and Methods: We performed dipyridamole stress, 4 hour redistribution, and 24 hour reinjection Tl-201 SPECT in 16 patients with AMI two to nine days after attack. Perfusion and wall motion abnormalities were quantified by perfusion index (PI) and wall motion index (WMI). Left ventricular ejection fraction (LVEF), WMI and ventricular volume were measured within 1 week of AMI and after average of 6 months. According to serial changes of left ventricular end-diastolic volume (LVEDV), patients were divided into two groups. We compared WMI, PI and LVEF between the two groups. Relationships among degree of volume, stress-rest PI, WMI, CKMB, Q wave, LVEF and revascularization were analysed using multivariate analysis. Results: Only initial rest perfusion index was significantly different between the two groups (p<0.05). While initial LVEF, stress PI, CKMB, trial of revascularization procedure, presence of Q wave and WMI were not significantly different between the two groups. Eight of 16 patients (50%) showed LV dilatation on follow-up echocardiography. Three of 3 patients (100%) who did not undergo revascualrization procedure documented LV dilatation. And only 5 (38%) of the remaining 13 patients who underwent revascularization revealed LV dilatation. There was no difference in infarct location between the two groups. By multivariate linear regression analysis in patients only undergoing revascularization, rest perfusion index was the only significant factor. Conclusion: Myocardial perfusion SPECT performed prior to revascularization was useful in prediction of LV dilatation after an AMI. Rest perfusion index on myocardial perfusion plays as a significant predictor of left ventricular dilatation after AMI. And revascularization appears to be a valuable procedure in alleviating LV dilatation after AMI with or without viable myocardium in a limited number of patients studied retrospectively.

• Journal of Chest Surgery
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• v.30 no.10
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• pp.966-972
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• 1997

Between June 1994 to August 1996, 13 patients underwent emergency coronary artery bypass operations. There were 3 males and 10 females and ages ranged from 56 to 80 years with the mean of 65.5 years. The indications for emergency operations were cardiogenic shock in 12 cases and intractable polymorphic VT(ve'ntricular tachycardia) in 1 case. The causes of cardiogenic shock were acute evolving infarction in 6 cases, PTCA failure in 4 cases, acute myocardial infarction in 1 case, and post-AMI VSR(ventricular septal rupture) in 1 case. Pive out of 13 patients could go to operating room within 2 hours. However, the operations were delayed from 3 to 10 hours in 8 patients due to non-medical causes. In 12 patients, 37 distal anastomoses were constructed with only 3 LITA's(left internal thoracic arteries) and 34 saphenous veins. In a patient with post-AMI VSR, VSR repair was added. In a patient with intractable VT and critical sten sis limited to left main coronary artery, left main coronary angioplasty was performed. Pive patients died after operation with the operative mortality of 38.5%. Three patients died in the operating room due to LV pump failure, one patient died due to intractable ventricular tachycardia on postoperative second day, and one patient died on postoperative 7th day due to multi-organ failure with complications of mediastinal bleeding, low cardiac output syndrome, ARF, and lower extremity ischemia due to IABP. In 8 survived patients, 3 major complications (mediastinitis, PMI, UGI bleeding) developed but eventually recovered. We think that the aggressive approach to critically ill patients will salvage some of such patients and the most important factor for patient salvage is early surgical intervention before irreversible damage occurs.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.282-286
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• 1997

In the era of coronary artery bypass grafting, the intraaortic balloon pump (IABP) is more widely used and its indication has been ex anded. We perf'orbed retrospective clinical analysis on the patients who have received IABP pre andfor postoperatively during the course of CABG. From January 1981 to June 1995, total 322 patients have received CABG at the Seoul National University Hospital and among them 50 patients (15.5%) were supported by IABP during the course of the operation. The mean age at the time. of the operation was 57.2 years (39∼ 75 years) and the male to female ratio was 33 : 17. The preoperative diagnosis was unstable angina in 33 (66%), stable angina in 7 (14%) and postinfarct angina in 8 patients(16%). As for the indications of the IABP, there were 13 cases(26%) with left main disease, 13 (26%) with class IV angina, 12 (24%) with difficulty in CPB weaning, 6 (12%) with postinfarct angina and 3 (6%) with severe LV dysfunction. In the remaining 3 cases, one patient was operated on after PTCA failure in emergency basis, another was a patient with AMI, and the other was one who had postoperative low c rdiac output syndrome. All IABPS were introduced via femoral artery and among them 45 cases (90%) percutaneously. The mean postoperative assist time was 22.3 hours (0.5 ∼ 168 hours) and IABP could be removed within 48 hours in most of them (44150). The operative mortality was 6.1% (3 cases) and postoperative morbidity was only one with lower extremity ischemia. The more general application of the IABP during the course of the CABG ,especially in patients with high preoperative risk factors or difficulty in CPB weaning is a good measure of protecting and recovering myocardial function with minimal risk.