• Journal of Chest Surgery
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• v.41 no.1
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• pp.41-48
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• 2008

Background: Accurate assessment of the preload and the fluid responsiveness is of great importance for optimizing cardiac output, especially in those patients with coronary artery occlusive disease (CAOD). In this study, we evaluated the relationship between the parameters of preload with the changes in the stroke volume index (SVI) after fluid loading in patients who were undergoing coronary artery bypass grafting (CABG). The purpose of this study was to find the predictors of fluid responsiveness in order to assess the feasibility of using. certain parameters of preload as a guide to fluid therapy. Material and Method: We studied 96 patients who were undergoing CABG. After induction of anesthesia, the hemodynamic parameters were measured before (T1) and 10 min after volume replacement (T2) by an infusion of 6% hydroxyethyl starch 130/0.4 (10 mL/kg) over 20 min. Result: The right ventricular end-diastolic volume index (RVEDVI), as well as the central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP), failed to demonstrate significant correlation with the changes in the SVI (%). Only the right ventricular ejection fraction (RVEF) measured at T1 showed significant correlation. with the changes of the SVI by linear regression (r=0.272, p=0.017). However, when the area under the curve of receiver operating characteristics (ROC) was evaluated, none of the parameters were over 0.7. The volume-induced increase in the SVI was 10% or greater in 31 patients (responders) and under 10% in 65 patients (non-responders). None of the parameters of preload measured at T1 showed a significant difference between the responders and non-responders, except for the RVEF. Conclusion: The conventional parameters measured with a volumetric pulmonary artery catheter failed to predict the response of SVI following fluid administration in patients suffering with CAOD.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.203-209
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• 1993

Dipyridamole is an agent that may be used to noninvasively evaluate coronary artery disease. The effect of dipyridamole infusion its generally related to its induced peripheral vasodilatory effect. In normal person, heart rate is generally increased slightly while blood pressure decrease, but the achieved double product and related myocardial oxygen consumption have no significant change. The purpose of this study is to examine the effect and side effect of dipyridamle, and to compare different response to dipyridamole among the patients. We evaluated 847 patients who underwent dipyridamole stress myocardial SPECT. 93.6% of them had induced hypotension, 0.9% showed no change of blood pressure, 5.5% had increased blood pressure. 8.3% had no change of pulse rate more than 10% of basal pulse rate. Among diabetes, 16.9% was not change of pulse rate, 6.7% in non-diabetes. There was no significant correlation between age and rate pressure product rest(RPPr), in patiens without perfusion defects on SPECT(y=7.1x+ 48.4 r=0.13 p>0.01). As increasing age, RPPs/RPPr was declined(y= -11.6x+68.9 r=0.17 p<0.01), similar results were obtained in patients with perfusion defect. The size of perfusion defect on myocardial SPECT have no correlation between RPPr and RPPs/RPPr. The side effects of dipyridamole included chest pain and chest tightness, headache, abdominal pain, dizzness, nausea, and dyspnea. As increasing age, dipyridamole-induced cardiac work at rest was increased, cardiac response to dipyridamole was decreased.

• The Korean Journal of Nuclear Medicine
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• v.35 no.1
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• pp.33-42
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• 2001

Purpose: The purpose of this study was to evaluate the effect of scatter correction on the assessment of myocardial perfusion and left ventricular function by gated Tc-99m myocardial SPECT. Materials and Methods: Subjects were 11 normal volunteers, 20 patients with non-cardiac chest pain and 13 patients with coronary artery diseases. We classified above 3 groups into normal and diseased groups. Scatter correction was done using dual-energy-window scatter correction method (DEW-SC). We compared acquired counts, image contrast, corrected maximum relative counts, indices of left ventricular function, extent and severity of perfusion defects calculated by 'CEqual program' between scatter non-corrected and corrected images. Results: Scatter corrected studios was lower in counts by $18{\pm}3%$ than uncorrected studies, but image contrast were improved in all cases. Scatter correction using DEW-SC took 3 minutes to complete, and 512 kB memory to store. There were no significant differences among indices of left ventricular function between scatter non-corrected and corrected images. Although extents of perfusion defects were not significantly different, severity was severer in scatter corrected images. Conclusion: Scatter correction using DEW-SC is simple to do, and improves image contrast without changing other indices of myocardial perfusion and function.

• Journal of Chest Surgery
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• v.39 no.7 s.264
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• pp.534-543
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• 2006

Background: There are a lot of debates regarding the optimal timing of operation of acute myocardial infarction (AMI). Off pump coronary artery bypass grafting (OPCAB) has benefits by avoiding the adverse effects of the cardio-pulmonary bypass, but its efficacy in AMI has not been confirmed yet. The purpose of this study is to evaluate retrospectively early and mid-term results of OPCAB in patients with AMI according to transmurality and timing of operation. Material and Method: Data were collected in 126 AMI patients who underwent OPCAB between January 2002 and July 2005, Mean age of patients were 61.2 years. Male was 92 (73.0%) and female was 34 (27.2%). 106 patients (85.7%) had 3 vessel coronary artery disease or left main disease. Urgent or emergent operations were performed in 25 patients (19.8%). 72 patients (57.1%) had non-transmural myocardial infarction (group 1) and 52 patients (42.9%) had transmural myocardial infarction (group 2). The incidence of cardiogenic shock and insertion of intra-aortic balloon pump (IABP) was higher in group 2. The time between occurrence of AMI and operation was divided in 4 subgroups (<1 day, $1{\sim}3\;days,\;4{\sim}7\;days$, >8 days). OPCAB was performed a mean of $5.3{\pm}7.1$ days after AMI in total, which was $4.2{\pm}5.9$ days in group 1, and $6,6{\pm}8.3$ days in group 2. Result: Mean distal an-astomoses were 3.21 and postoperative IABP was inserted in 3 patients. There was 1 perioperative death in group 1 due to low cardiac output syndrome, but no perioperative new MI occurred in this study. There was no difference in postoperative major complication between two groups and according to the timing of operation. Mean follow-up time was 21.3 months ($4{\sim}42$ months). The 42 months actuarial survival rate was $94.9{\pm}2.4%$, which was $91.4{\pm}4.7%$ in group 1 and $98.0{\pm}2.0%$ in group 2 (p=0.26). The 42 months freedom rate from cardiac death was $97.6{\pm}1.4%$ which was $97.0{\pm}2.0%$ in group 1 and $98.0{\pm}2.0%$ in group 2 (p=0.74). The 42 months freedom rate from cardiac event was $95.4{\pm}2.0%$ which was $94.8{\pm}2.9%$ in group 1 and $95.9{\pm}2.9%$ in group 2 (p=0.89). Conclusion: OPCAB in AMI not only reduces morbidity but also favors hospital outcomes irrespective of timing of operation. The transmurality of myocardial infarction did not affect the surgical and midterm outcomes of OPCAB. Therefore, there may be no need to delay the surgical off-pump revascularization of the patients with AMI if surgical revascularization is indicated.