• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.979-984
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• 2006

Although iron is essential for many physiological processes, excess iron can lead to tissue damage by promoting the generation of reactive oxygen species (ROS). There is increasing evidence that ROS might play an important role in the pathogenesis of cardiovascular disease. However, the effects of iron excess on platelet function and the thrombotic response to vascular injury are not well understood. We examined the effects of iron excess-induced oxidative stress and the antioxidants on platelet aggregation. Oxidative stress was accessed by either free iron $(Fe^{+2})$ or hydrogen peroxide $(H_2O_2)$, as well as their combination on washed rabbit platelets (WPs) in vitro. When WPs were stimulated with either $Fe^{+2}$ alone or a subthreshold concentration of collagen, which gave an aggregatory curve with a little effect, and a dose dependent increase in platelet aggregation was observed by increasing concentrations of $Fe^{+2}$ with $H_2O_2$. This aggregation was associated with the iron-catalyzed formation of hydroxyl radicals from $H_2O_2$, and were inhibited by NAD/NADP (proton acceptor), catalase $(H_2O_2\;scavenger)$, tiron (iron chelator), mannitol (hydroxyl radical scavenger), and indomethacin (cyclooxygenase inhibitor), but not by NADH/NADPH (proton donor), superoxide mutase, and aspirin. However, NADH/NADPH, an essential cofactor for the antioxidant capacity by the supply of reducing potentials, showed the effect of an enhanced radical formation, suggesting a role for NADH/NADPH-dependent oxidase. These results suggest that iron $(Fe^{+2})$ can directly interact with washed rabbit platelets and this aggregation be mediated by OH formation as in the Fenton reaction, inhibited by radical scavengers.

• Journal of Chest Surgery
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• v.52 no.4
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• pp.248-329
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• 2019

Background: Though clinical practice guidelines (CPGs) for cardiac rehabilitation (CR) are an effective and widely used treatment method worldwide, they are as yet not widely accepted in Korea. Given that cardiovascular disease is the second leading cause of death in Korea, it is urgent that CR programs be developed. In 2008, the Government of Korea implemented CR programs at 11 university hospitals as part of its Regional Cardio-Cerebrovascular Center Project, and 3 additional medical facilities will be added in 2019. In addition, owing to the promotion of CR nationwide and the introduction of CR insurance benefits, 40 medical institutions nationwide have begun CR programs even as a growing number of medical institutions are preparing to offer CR. The purpose of this research was to develop evidence-based CPGs to support CR implementation in Korea. Methods: This study is based on an analysis of CPGs elsewhere in the world, an extensive literature search, a systematic analysis of multiple randomized control trials, and a CPG management, development, and assessment committee comprised of 33 authors-primarily rehabilitation specialists, cardiologists, and thoracic surgeons in 21 university hospitals and 2 general hospitals. Twelve consultants, primarily rehabilitation, sports medicine, and preventive medicine specialists, CPG experts, nurses, physical therapists, clinical nutritionists, and library and information experts participated in the research and development of these CPGs. After the draft guidelines were developed, 3 rounds of public hearings were held with staff members from relevant academic societies and stakeholders, after which the guidelines were further reviewed and modified. Results: CR involves a more cost-effective use of healthcare resources relative to that of general treatments, and the exercise component of CR lowers cardiovascular mortality and readmission rates, regardless of the type of coronary heart disease and type and setting of CR. Conclusion: Individualized CR programs should be considered together with various factors, including differences in heart function and lifestyle, and doing so will boost participation and adherence with the CR program, ultimately meeting the final goals of the program, namely reducing the recurrence of myocardial infarction and mortality rates.

• Journal of Chest Surgery
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• v.37 no.10
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• pp.817-826
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• 2004

Background: Several studies have demonstrated that conventional hypothermic cardiopulmonary bypass (CPB) causes cellular injury, abnormal responses in peripheral vascular beds and increased postoperative bleeding, whereas normothermic CPB provides protection of the hypothermic-induced effects and better cardiac recovery. The present study was prospectively performed to compare the effects of normothermic CPB to those of hypothermic CPB on the inflammatory and hematologic responses during cardiac surgery. Material and Method: Thirty-four adult patients scheduled for elective cardiac surgery were randomly assigned to hypothermic CPB (nasopharyngeal temperature $26～28^{\circ}C,$ n=17) or normothermic CPB (nasopharyngeal $temperature>35.5^{\circ}C,$ n=17) group. In both groups, cold $(4^{\circ}C)$ crystalloid cardioplegia was applied for myocardial protection. Blood samples were drawn from radial artery before (Pre-CPB), 10 minutes after starting (CPB-10) and immediately after ending (CPB-OFF) CPB. Total leukocyte and platelet counts, interleukin-6 (IL-6) level(expressed as percent to the baseline of Pre-CPB), D-dimer level, protein C and protein S activity were measured with the blood samples. The amount of bleeding for postoperative 24 hours and blood transfusion after operation were also assessed. All parameters were compared between the two groups. Result: The total leukocyte counts $(10,032\pm65/mm^3)$ and the increased ratio of IL-6 $(353\pm7.0%)$ at CPB-OFF in the normothermic group were higher than that $(7,254\pm48/mm^3$ and $298\pm7.3%)$ of the hypothermic group(p=0.02 and p=0.03). In the normothermic group, protein C activity $(32\pm3.8%)$ and protein S activity $(35\pm4.1%)$ at CPB-OFF were significantly lower than that $(45\pm4.3%$ and $51\pm3.8%)$ of the hypothermic group (p=0.04 and p=0.009). However, there were no differences in platelet counts and D-dimer concentration. In the normothermic group, the amount of bleeding for postoperative 24 hours $(850\pm23.2$ mL) and requirements for blood transfusion after operation such as packed cell $(1,402\pm20.5$ mL), fresh frozen plasma $(970\pm20.8$ mL) and platelet $(252\pm6.4$ mL) were higher than that $(530\pm21.5$ mL, $696\pm15.7$ mL, $603\pm18.2$ mL and $50\pm0.0$ mL) of the hypothermic group. Conclusion: These results indicate that normothermic CPB with cold crystalloid cardioplegia was associated with higher increase in inflammatory response, hemostatic abnormalities and postoperative bleeding problem than moderate hypothermic CPB.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.27-34
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• 2004

Background: Infective endocarditis shows higher operative morbidity and mortality rates than other cardiac diseases. The vast majority of studies on infective endocarditis have been made on aortic endocarditis, with little attention having been paid to infective endocarditis on the mitral valve. This study attempts to investigate the clinical aspects and operative results of infective endocarditis on the mitral valve. Meterial and Method: The subjects of this study consist of 23 patients who underwent operations for infective endocariditis on the mitral valve from June 1995 to May 2003. Among them, 2 patients suffered from prosthetic valvular endocarditis and the other 21 from native valvular endocarditis. The subjects were evenly distributed age-wise with an average age of 44.8$\pm$15.7 (11∼66) years. Emergency operations were performed on seventeen patients (73.9%) due to large vegetation or instable hemodynamic status. In preoperative examinations, twelve patients exhibited congestive heart failure, four patients renal failure, two patients spleen and renal infarction, and two patients temporary neurological defects, while one patient had a brain abscess. Based on the NYHA functional classification, seven patients were determined to be at Grade II, 9 patients at Grade III, and 6 patients at Grade IV. Vegetations were detected in 20 patients while mitral regurgitation was dominant in 19 patients with 4 patients showing up as mitral stenosis dominant on the preoperative echocardiogram. Blood cultures for causative organisms were performed on all patients, and positive results were obtained from ten patients, with five cases of Streptococcus viridance, two cases of methicillin-sensitive Staphylococcus aureus, and one case each of Corynebacteriurn, Haemophillis, and Gernella. Operations were decided according to the AA/AHA guidelines (1988). The mean follow-up period was 27.6 $\pm$23.3 (1 ∼ 97) months. Result: Mitral valve replacements were performed on 43 patients, with mechanical valves being used on 9 patients and tissue valves on the other 4. Several kinds of mitral valve repair or mitral valvuloplasty were carried out on the remaining 10 patients. Associated procedures included six aortic valve replacements, two tricuspid annuloplasty, one modified Maze operation, and one direct closure of a ventricular septal defect. Postoperative complications included two cases of bleeding and one case each of mediastinitis, low cardiac output syndrome, and pneumonia. There were no cases of early deaths, or death within 30 days following the operation. No patient died in the hospital or experienced valve related complications. One patient, however, underwent mitral valvuloplasty 3 months after the operation. Another patient died from intra-cranial hemorrhage in the 31st month after the operation. Therefore, the valve-related death rate was 4.3%, and the valve-related complication rate 8.6% on mid-term follow-up. 1, 3-, and 5-year valve- related event free rates were 90.8%, 79.5%, and 79.5%, respectively, while 1, follow-up. 1, 3-, and 5-year valve- related event free rates were 90.8%, 79.5%, and 79.5%, respectively, while 1, 3-, and 5-year survival rates were 100%, 88.8%, and 88.8%, respectively. Conclusion: The findings suggest that a complete removal of infected tissues is essential in the operative treatment of infectious endocarditis of the mitral valve. It is also suggested that when infected tissues are completely removed, neither type of material nor method of operation has a significant effect on the operation result. The postoperative results also suggest the need for a close follow-up observation of the patients suspected of having brain damage, which is caused by preoperative blood contamination or emboli from vegetation, for a possible cerebral vascular injury such as mycotic aneurysm.