• Investigative Magnetic Resonance Imaging
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• v.12 no.1
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• pp.40-48
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• 2008

Purpose : We sought to determine the early change of ventricular geometry and function after concomitant surgeries of modified Dor procedure and mitral valve annuloplasty by using magnetic resonance imaging. Materials and Methods : We enrolled 21 patients with dilated heart failure who underwent modified Dor procedure (n=8), mitral valve annuloplasty (n=6), or both surgeries (n=7). Cine MRI was used to assess left ventricular dimensions and function before and after surgery. We measured the left ventricular end-diastolic and end-systolic volumes and the dimensions of the left ventricular long-axis and short-axis. Left ventricular stroke volume, ejection fraction, and sphericity index were calculated from these measurements. These parameters were analyzed and compared between three different surgery groups to explain the combined effect of the concomitant surgeries. Results : MRI was performed within average $12\;{\pm}\;15$ days (range 1-58 days) before and $38\;{\pm}\;50$ days (range 7- 231 days) after the surgery. The patients who underwent concomitant surgeries had more profound enlargement of left ventricle and decreased contractility prior to surgery than those in the patients who underwent single surgical procedure. Left ventricular end-diastolic volume and endsystolic volume significantly decreased in all patients regardless of surgery type after surgery. Ejection fraction significantly increased only in the patients who got modified Dor procedure without mitral valve annuloplasty (25.4% to 40.7%). Sphericity index increased in patients with modified Dor procedure but decreased in patients with mitral valve annuloplasty (0.65 to 0.78 vs. 0.75 to 0.65). In the patients who underwent concomitant surgeries showed no significant change in sphericity index after surgery. Conclusion : The early change of the left ventricular geometry and function after the concomitant surgeries with modified Dor procedure and mitral valve annuloplasty in patients with dilated heart failure includes a marked reduction in left ventricular volume and in stroke volume. The shape of the left ventricle does not change because the effect of sphericity index decrease from mitral valve annuloplasty is counteracted by the effect of sphericity index increase from modified Dor procedure. Improvement of left ventricular ejection fraction is not the early change after the concomitant surgeries.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.211-222
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• 1988

Tetralogy of Fallot is a cyanotic congenital heart disease characterized by large ventricular septal defect[VSD] and stenosis of right ventricular outflow tract[RVOT] and the degree of RVOT stenosis and the state of pulmonary arteries are the major determinant of prognosis of this anomaly after operation. The sum of blood flow through RVOT and collateral flow from systemic arteries determine the total pulmonary blood flow and it is drained to left atrium and left ventricle. Therefore the degree of development of left ventricle not only reflects pulmonary blood flow and the status of peripheral pulmonary arteries but also affects postoperative prognosis as a systemic ventricle. In this article, left ventricular volume and its influence on postoperative cardiac function in tetralogy of Fallot were studied in 34 patients operated on at Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital in 1985. Mean age of the patients was 5 1/12*3 9/12 years[range 9/12 - 14 8/12 years], mean body surface area[BSA] 0.65*0.20m2[range 0.38 - 1.22m2], mean body weight 15.6k6.48kg[range 7.0 - 36kg]and mean hematocrit 50.6*9.77%[range 32.0 - 73.5%]. Left ventricular end-diastolic volume[LVEDV] of them were from 11.2 to 113cc and there was a good linear correlation between BSA[m2, X]and LVEDV[cc, Y][Y= - 20.0+923x, r= 0.84, p < 0.005]. Mean LVEDV/m2 was [57.6 * 18.3 cc / m2[range 28.7 - 95.8 cc / m2] and there was a significant reduction of volume compared with normal value. As body surface increases, there was a increasing tendency in LVEDV/m2 but there was no statistical significance. Mean total amount of postoperatively infused dopamine in these 33 patients[except one who expired postoperatively] was 65.6*74.5mg / kg and it was 40.6*44.0mg / kg in routine RVOT widening group [Group I] and 205*49.3mg / kg in transannular RVOT widening group[Group II]. There was a statistically significant difference between two groups. In group I patients there was a good linear inverse correlation between dopamine total amount[mg / kg, Y] and LV volume[cc / m2, X] [Y = 150 - 1.89 X, r = - 0. 77, p < 0.005]. But there were no correlations between dopamine total amount and Hct, cardiopulmonary bypass time and aorta cross clamp time. In conclusion, the patient with small preoperative left ventricular volume required more amount of dopamine as an inotropic agent for the maintenance of a cardiac function in postoperative period. But this is a result of immediate postoperative period and does not reflect the long term effect of left ventricular volume in tetralogy of Fallot. There must be more study for the evaluation of its long term effect.

• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.63-66
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• 2005

Surgical anterior ventricular endocardial restoration (SAVER) is a technique that improves hemodynamic status by excluding akinetic or dyskinetic portions of the left ventricle, restores the ventricle to normal elliptical shape and reduces ventricular wall tension to normal level in patients with acute anterior wall myocardial infarction that accompanies aneurysm. We performed redo-SAVER procedure in a 40-year old man with remodeled dilated ventricle who had already underwent LV aneurysmectomy 12 years earlier, and the results were satisfactory.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.755-761
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• 2004

We evaluated the efficacy of Dor procedure in patients with ischemic left ventricular dysfunction. Material and Method: Between April 1998 and December 2002, 45 patients underwent the Dor procedure con-comitant with coronary artery bypass grafting (CABG). Left ventricular ejection fraction (LVEF) and left ventricular end-diastolic/end-systolic volumes (LVEDV/LVESV) were measured by echocardiography, myocardial SPECT, and cardiac catheterization and angiography performed at the sequence of preoperative, early postoperative, and one year postoperative stage. Result: Cardiopulmonary bypass and aortic clamp times were mean 141$\pm$64, 69$\pm$24 minutes, respectively. Intraaortic balloon pump (IABP) therapy was required in 19 patients (42%; 7 preoperatively, 9 intraoperatively, 3 postoperatively). Operative mortality rate was 2.2% (1/45). Postoperative morbidities were low cardiac output syndrome (12), atrial fibrillation (5), acute renal failure (4), and postoperative bleeding (4). Functional class (NYHA) was improved from classes 2.8 to 1.1 (p < 0,01). When we compared between the preoperative and early postoperative values, LVEF was improved from 32$\pm$9% to 52$\pm$11% (p<0.01). The asynergy portion decreased from 57$\pm$12% to 22$\pm$9%, and LVEDV/LVESV indexes improved from 125$\pm$39 mL/$m^2$, 85$\pm$30 mL/$m^2$ to 66$\pm$23 mL/$m^2$, 32$\pm$16 mL/$m^2$ (p<0.01). Although these changes in volumes were relatively preserved at postoperative one year, the left ventricular volumes showed a tendency to increase. Conclusion: After the Dor procedure for ischemic left ventricular dysfunction, LVEF improvement and left ventricular volume reduction were maintained till postoperative one year. The tendency for left ventricular volume to increase at postoperative one year suggested the requirement of strict medical management.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.224-236
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• 1999

Background: To evaluate the short-term effect of dynamic cardiomyoplasty on circulatory function and detect the related factors that can affect it, experimental cardiomyoplasties were performed under the state of normal cardiac function and heart failure. Material and Method: A total of 10 mongrel dogs weighing 20 to 30kg were divided arbitrarily into two groups. Five dogs of group A underwent cardiomyoplasty with latissimus dorsi(LD) muscle mobilization followed by a 2-week vascular delay and 6-week muscle training. Then, hemodynamic studies were conducted. In group B, doxorubicin was given to 5 dogs in an IV dose of 1 mg/kg once a week for 8 weeks to induce chronic heart failure, and simultaneous muscle training was given for preconditioning during this period. Then, cardiomyoplasties were performed and hemodynamic studies were conducted immediately after these cardiomyoplasties in group B. Result: In group A, under the state of normal cardiac function, only mean right atrial pressure significantly increased with the pacer-on(p<0.05) and the left ventricular hemodynamic parameters did not change significantly. However, with pacer-on in group B, cardiac output(CO), rate of left ventricular pressure development(dp/dt), stroke volume(SV), and left ventricular stroke work(SW) increased by 16.7${\pm}$7.2%, 9.3${\pm}$3.2%, 16.8${\pm}$8.6%, and 23.1${\pm}$9.7%, respectively, whereas left ventricular end-diastole pressure(LVEDP) and mean pulmonary capillary wedge pressure(mPCWP) decreased by 32.1${\pm}$4.6% and 17.7${\pm}$9.1%, respectively(p<0.05). In group A, imipramine was infused at the rate of 7.5mg/kg/hour for 34${\pm}$2.6 minutes to induce acute heart failure, which resulted in the reduction of cardiac output by 17.5${\pm}$2.7%, systolic left ventricular pressure by 15.8${\pm}$2.5% and the elevation of left ventricular end-diastole pressure by 54.3${\pm}$15.2%(p<0.05). With pacer-on under this state of acute heart failu e, CO, dp/dt, SV, and SW increased by 4.5${\pm}$1.8% and 3.1${\pm}$1.1%, 5.7${\pm}$3.6%, and 6.9${\pm}$4.4%, respectively, whereas LVEDP decreased by 11.7${\pm}$4.7%(p<0.05). Comparing CO, dp/dt, SV, SW and LVEDP that changed significantly with pacer-on, both under the state of acute and chronic heart failure, augmentation widths of these left ventricular hemodynamic parameters were significantly larger under the state of chronic heart failure(group B) than acute heart failure(group A)(p<0.05). On gross inspection, variable degrees of adhesion and inflammation were present in all 5 dogs of group A, including 2 dogs that showed no muscle contraction. No adhesion and inflammation were, however, present in all 5 dogs of group B, which showed vivid muscle contractions. Considering these differences in gross findings along with the following premise that the acute heart failure state was not statistically different from the chronic one in terms of left ventricular parameters(p>0.05), the larger augmentation effect seen in group B is presumed to be mainly attributed to the viability and contractility of the LD muscle. Conclusion: These results indicate that the positive circulatory augmentation effect of cardiomyoplasty is apparent only under the state of heart failure and the preservation of muscle contractility is important to maximize this effect.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.611-618
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• 2006

Background: There have been controversies whether mitral valvular surgery is necessary in the patients with moderate ischemic mitral regurgitation undergoing coronary artery bypass grafting. The purpose of this study is to evaluate the long term clinical results of patients with moderate ischemic mitral regurgitation. Material and Method: Between January 1992 and February 2005, 44 patients with moderate ischemic mitral regurgitation underwent coronary artery bypass grafting. Concomitant mitral valvular procedure was performed in 20 patients (group 1) and isolated coronary artery bypass grafting was performed in 24 patients (group 2). There were no significant difference between groups except cardiopulmonary bypass time (p<0.01). Postoperative follow up duration was $30.1{\pm}29.6$ months and last follow up echocardiographic examination was performed at $21.2{\pm}28.0$ months. Result: There was no difference in operative mortality between groups (group 1 vs group 2, 15.0% vs 8.3%, p=0.493). Grade of mitral regurgitation ${(0.81{\pm}0.91\;vs\;1.50{\pm}0.05,\;p=0.046)}$ and reduction in regurgitation grade ${(1.75{\pm}0.93\;vs\;0.70{\pm}1.26,\;p=0.009)}$ were different between two groups. But there were no significant differences in left ventricular ejection fraction ${(34.1{\pm}11.4%\;vs\;41.6{\pm}12.9%)}$, left ventricular end systolic volume ${(118.2{\pm}63.9\;ml%\;vs\;85.6{\pm}281\;ml)}$, New York Heart Association functional class ${(2.1{\pm}0.2\;vs\;2.4{\pm}1.2)}$ and 5 year survival rate ${(85{\pm}8%\;vs\;82{\pm}8%)}$. There was no risk factor for operative mortality and the only risk factor for late death was preoperative atrial fibrillation (p=0.042). There was no significant correlation between mitral valvular surgery and late death. Conclusion: Concomitant mitral valvular procedure in patients with moderate ischemic mitral regurgitation undergoing coronary artery bypass grafting had no significant positive effect on survival and ventricular function compared with isolated coronary artery bypass grafting. Prospective randomized study may be needed to evaluate the necessity of concomitant mitral procedure and to find more effective method for the improvement of ventricular function.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.422-427
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• 1999

Background: Tachycardia induced heart failure model would be the model of choice for the dilated cardiomyopathy. This more closely resembles the clinical syndrome and does not require major surgical trauma, myocardial ischemia and pharmacological or toxic depression of cardiac function. When heart failure is progressive, application of new surgical procedures to the faling heart is highly risky. It has been shown that recovery trajectory from heart failure is a new method in decreasing animal mortality. The purpose is to establish the control datas for recovery trajectory in the canine heart failure model. Material and Method: 21 mongrel dogs were studied at 4 stages(baseline, at the heart failure, 4 and 8 weeks after recovery). Heart failure was induced during 4 weeks of continuous rapid pacing using a pacemaker. Eight weeks of trajectory of recovery period was allowed. Indices of left ventricular function and dimension were measured every 2 weeks and the hemodynamics were measured by use of Swan-Ganz catheterization and thermodilution method every 4 weeks. Values were expressed as mean${\pm}$standard deviation. Result: 4(20%) dogs died due to heart failure. Left ventricular end-diastolic volume at the 4 stages were 40.8${\pm}$7.4, 82.1${\pm}$21.1, 59.9${\pm}$7.7 and 46.5${\pm}$6.5ml. Left ventricular end-systolic volume showed the same trend. Ejection fractions were 50.6${\pm}$4.1, 17.5${\pm}$5.8, 36.3${\pm}$7.3, and 41.5${\pm}$2.4%. Blood pressure and heart rate showed no significant changes. Pressures of central vein, right ventricle, pulmonary artery, and pulmonary capillary wedge showed significant increase during the heart failure period, normalizing at the end of recovery period. Stroke volumes were 21.5${\pm}$8.2, 12.3${\pm}$3.5, 17.9${\pm}$4.6, and 15.5${\pm}$3.4ml. Blood norepinephrine level was 133.3${\pm}$60.0pg/dL at the baseline and 479.4${\pm}$327.3pg/dL at the heart failure stage(p=0.008). Conclusion: Development of tachycardia induced heart failure model is of high priority due to ready availability and reasonable amenability to measurements. Recovery trajectory after cessation of tachycardia showed reduction of cardiac dilatation and heart function. Application of new surgical procedures during the recovery period could decrease animal mortality.

• Journal of Chest Surgery
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• v.35 no.4
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• pp.261-266
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• 2002

In an attempt to avoid the adverse effects of the cardiopulmonary bypass, off pump coronary artery bypass grafting(Off pump CABG) that has recently been rediscovered and refined. We compared the preoperative risk factors and in-hospital outcomes of patients done Off pump with those done On pump CABG. Material na Method: One hundred seventy eight patients was underwent CABG between January 2001 and July 2001 12 patients whom underwent associated valvular or left ventricular volume reduction surgery were excluded in this study Data were collected for 52 Off pump CABG and 114 On pump CABG for patient and disease risk factors, extent of coronary disease, and in-hospital outcomes. Result: Off pump CABG and On pump CABG groups did not show any differences in their patient and disease risk factors, and extent of coronary disease. Off pump CABG group had significantly lower mean operation time(234 $\pm$ 37 min vs 290 $\pm$ 48 min, p<0.001), lower mean CK-MB level(10.1 $\pm$ 13.5 IU/L vs 33.1 $\pm$ 18.2 IU/L, p<0.001) and mean ventilation time(14.8 $\pm$ 3.5 hours vs 16.2 $\pm$ 4.9 hours, p=0.048) than On pump CABG groups. On pump CABG group had significantly more distal grafts(3.4 $\pm$ 0.9 vs 2.6 $\pm$ 0.8, p<0.001) than Off pump CABG groups. There were no operative mortality in two groups. Off pump) CABG and On pump CABG groups did not show any differences in their postoperative complications and outcomes including perioperative myocardial infarction, stroke, respiratory failure, renal failure, reoperation, the amount of bleeding, the need of intraaortic balloon pump, the need of inotropics, and the stay of intensive care unit and hospital. Two patients were converted to On pump CABG. Conclusion: This study showed that patients having Off pump CABG are not exposed to a greater risks of adverse outcomes and also provided evidence that patients having Off pump CABG have significantly lower operation time, CK-MB, ventilation time and less distal grafts. Although there may be potential benefits to Off pump CABG, further studies must be directed to determine those patients who would benefit from Off pump CABG.