• Journal of Chest Surgery
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• v.40 no.6 s.275
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• pp.445-447
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• 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 Biomedical Engineering Research
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• v.13 no.4
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• pp.285-298
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• 1992

An analysis of the dynamics in the closing phase of the occluder of a mechanical monoleaflet heart valve prosthesis is presented. The dynamic analysis of the fluid in the vicinity of the occluder was based on the control vo]use approach. The backflow velocity of the fluid was computed by applying the continuity, Bernoulli's and momentum equations in the unsteady state. By considering the fluid pressure and gravity as external forces acting on the occluder, the moment equilibrium on fine occluder was employed to analyze the motion of the occluder during closing and the force of impact between the occluder and the guiding struts. Occluder comes to rest after several oscillations in about 10-18 msec after the Inltiaton of closing. As the aortic pressure increases, the occludes closes faster and comes to the final resting position earlier and the impact force increases also. But backflow is not af footed by the variation of the aortic pressure. With decreasing time delay of the ventricle pressure, the occluder closes faster and impact force Increases. The computed magnitudes of the occluder tiP velocities as well as the backflow of the fluid during the closing phase using this model were in agreement with previously reported experimental measurements.

• Journal of Chest Surgery
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• v.56 no.6
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• pp.452-455
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• 2023

Patients who have undergone mechanical valve replacement require anticoagulation therapy with warfarin to prevent thromboembolism. However, administering warfarin to pregnant patients increases their risk of warfarin embryopathy or central nervous system disorders. Consequently, safer alternatives, such as heparin or low-molecular-weight heparin injection, are substituted for warfarin. However, limited research has been conducted on this subject, with no large-scale studies and particularly few investigations involving multiparous patients. A patient who had previously undergone mechanical mitral valve replacement for atrial septal defect and mitral stenosis received anticoagulant therapy with enoxaparin during 2 pregnancies. Upon confirmation of pregnancy, warfarin was replaced with subcutaneously injected enoxaparin with a dosage of 1 mg/kg at 12-hour intervals. The enoxaparin dosage was controlled using an anti-factor Xa assay, with a target range of 0.3-0.7 IU/mL. Intravenous heparin injections were administered starting 3 days prior to the expected delivery date and were continued until delivery, after which warfarin was resumed. No complications were observed during the deliveries.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.436-439
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• 1985

A patient of Ebstein`s anomaly underwent surgical repair on Oct. 24th, 1984. Tricuspid valve was replaced by 31mm St. Jude mechanical valve without plication of atrialized right ventricle. The annulus has been placed below the coronary sinus, with care not to damage the conduction system. But postoperatively complete heart block developed. Permanent pacemaker was implanted on his 12th POD. Now he has been followed up for 9 months. There was no hemodynamic problems yet.

• Journal of the Korean Society of Visualization
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• v.22 no.1
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• pp.40-48
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• 2024

This study presents an in-vitro model designed to simulate mitral valve regurgitation, aiming to compare the quantification results between Proximal Isovelocity Surface Area(PISA) and 4D Flow MRI on both fixed and valve annulus tracking(VAT) views. The in-vitro model replicates the dynamic conditions of the mitral valve in a pulsatile environment, utilizing a piston pump set at 60 bpm. Through systematic experiments and analysis, the study evaluates the accuracy and effectiveness of PISA and 4D Flow MRI in assessing regurgitation severity, considering both fixed and valve annulus tracking. The displacement length measured in echo closely resembled that of optical measurements, making it advantageous for structural analysis. VAT-4D flow MRI exhibited the smallest deviation from actual flow rate values, establishing it as most accurate method for quantitative regurgitation assessment.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1102-1110
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• 1996

Between Oct. 1985 and July 1995, 230 patients underwent mitral valve replacement. There were 77 men and 153 women whose mean age was 35.7 years, range 9 to 62 The concomitant operations were 40 aortic valve replacements(17.4%), 25 tricuspid annuloplasties(10.4%), 8 aortic valve replacements & tricuspid annuloplasties(3.5%), 2 tricuspid valve replacements(0.9%) and others, We used 139 mechanical (76 51. Jude medical, 33 CarboMedics, 30 Sorin) and 91 tissue 386 Carpentier-Edwards, 5 lonescu-Shiley) valves. The early postoperative complications occurred in 28 cases. There were 8 low cardiac output syndrome, 5 pleural effusion, 3 significant arrhythmia, 2 cardiac rupture and others. There were 6 early hospital deaths (2.6%) due to low cardiac output syndrome(2), arrhythmia(2) and ventricul r rupture(2). The cuAmulative notal follow-up period was 764. 4 patient-years with a mean of 4).9 months. The long term follow-up information was available for 212 patients(94.6%). There were 21 cases of valve-related complications. Prosthetic valve failure(10), anti-coagulation related bleeding (5), prosthetic valve endocarditis (4), and thromboembolism (2) occurred at rates of 1.3, 0.7, 0.5, and 0.3%Ipt-yr respectively. Late death occurred In 5 cases (0.7%/pt-yr) associated with prosthetic valve endocarditis (2), heart failure (2) and anti-coagulation related bleeding (1). There was no difference in the rate of freedom from prosthetic valve failure between the mechanical and tissue valve group at 6 years (100%), but there was significant difference at 9 years between the tissue (34.4%) and mechanical valve (100%) group (p=0.032). Actuarial survival rates were 98. 8% in tissue valve. 9).7% in mechanical valve group and 96.6% in total patients at 9 years.

• 한국임상약학회:학술대회논문집
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• 2007.12a
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• pp.177-177
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• 2007

• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.77-80
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• 1993

• Journal of Chest Surgery
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• v.27 no.8
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• pp.664-668
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• 1994

A total of 217 patients underwent single mitral valve replacement [MVR] with the St. Jude Medical valve between September 1984 and the end of 1992. There were 86 males and 131 females with a mean age of 34.6 $\pm$ 14.4 years[range 5 months-61 years]. A previous valve replacement had been performed in 46 patients [21.2 %]. An early mortality rate was 7.4 % [5.2 % in primary MVR; and 15.2 %in re-replacement MVR]. Early survivors of 201 patients were followed up for a total of 934.5 patient-years[mean 4.7 $\pm$ 2.1years]. A late mortality rate was 2.5 % or 0.54%/patient-year. The linearized rates of thromboembolism, valve thrombosis and anticoagulation-related bleeding were 1.301 %, 0.214 % and 0.428 %/patient-year, respectively. The actuarial survival including operative mortality was 89.9 % $\pm$ 2.1% at postoperative 10 years. The freedom from thromboemolism was 91.3 %$\pm$ 2.5% and the actuarial estimate of incidence free from late deaths and all complications were 80.9 % $\pm$ 3.8 % at 10 years. There were no mechanical failures. In summary, the St. Jude Medical prosthesis performed satisfactorily with an acceptable rate of late complications.

• Korean Journal of Clinical Pharmacy
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• v.23 no.3
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• pp.232-238
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• 2013

Background: Although thromboembolism is common and one of the major causes of mortality in cancer patients, maintaining therapeutic anticoagulation effect with warfarin is challenging. This study aimed to determine the prevalence and the causes of non-therapeutic INR (International Normalized Ratio) in cancer patients. Methods: Medical and pharmacy records for cancer patients managed by the pharmacist-run anticoagulation service (ACS) between May, 2010 and April, 2011 at Seoul National University Hospital were retrospectively reviewed. The causes of non-therapeutic INR were identified and compared with the results from a former study with mechanical heart valve patients. Results: A total of 335 cancer patients and 6,737 patient-visits were analyzed producing 68% (n=4,590) of non-therapeutic INR readings. Eighty-five percent of the non-therapeutic INR readings were categorized as sub-therapeutic. Frequent causes linked to non-therapeutic INR included inadequate dosage adjustment (21.8%), changes in health status (11.8%), dietary changes (8.1%), and drug interactions (4.2%). More than half of the non-therapeutic INR values had no known etiology. As causes for non-therapeutic INR, changes in health status (p<0.0001), adverse reactions (p<0.0001), and dietary changes (p=0.017) were statistically more frequent in cancer patients than in patients with mechanical heart valves. Furthermore, exposure to sub-therapeutic INR were more prevalent in cancer patients than in patients with mechanical heart valve (p<0.0001). Conclusions: This study shows that there is a tendency to keep the level of INR low and that health status change, dietary change, and drug interactions are found to be frequent causes for non-therapeutic INR in cancer patients.