• Journal of Chest Surgery
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• v.23 no.3
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• pp.438-451
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• 1990

Pneumatic total artificial heart[TAH] has been clinically applied for the purpose of permanent or temporary use followed by cardiac transplantation in the patients with end stage heart diseases. In spite of the good durability of the pneumatic TAH, thrombus formation, bleeding and infection resulted in death. The Tomasu heart, which is a type of pneumatic TAH, was used in this study. This model is a modified Jarvik heart and consists of atrial cuffs, outflow vascular grafts and thin-layer seamless diaphragm type of ventricles. Cardiac outputs of the left artificial heart were measured by Donovan`s mock circulation under variable conditions of driving parameters, and an experimental artificial heart implantation was performed in 4 calves to observe the changes of hemodynamic parameters in early postoperative period and hematologic and bio-chemical changes in a long-term survival case. In the mock circulation test, cardiac output of the heart was increased with the increase of the left atrial pressure and left driving pressure. Maximum cardiac output was obtained at the heart rate of 120 to 130/min and percent systole of 40 to 45Zo under the condition of a constant left driving pressure of 180mmHg and left atrial pressure of 10mmHg. During the first 24 hours of TAH pumping, driving pressure ranged from 178$\pm$5mmHg to 187$\pm$8mmHg for the left heart and from 58$\pm$6mmHg to 78$\pm$28mmHg for the right heart. The Mean arterial pressure significantly increased between 2 and 8 hours after the start of pumping. The survival time ranged from 27 hours to 46 days. The causes of death were respiratory failure in 2 cases, mechanical valve failure in one, and left ventricular outflow obstruction due to thrombus in a 46-day survival case. This study demonstrated that Tomasu artificial heart operated effectively during the first 24 hours of artificial heart pumping, but thrombus formation around the valve holding area was the main problem in long-term survival case.

• Journal of Chest Surgery
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• v.27 no.6
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• pp.435-443
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• 1994

Surgical procedures to relieve congenital right ventricular outflow tract[RVOT] obstruction of heart were performed on 125 patients from September 1985 to August 1992. There were 65 males and 60 females. Ages ranged from 7 months to 33 years with a mean age of 8 years. All the patients were divided into three main groups[I, II, III] depending on the presence or absence of cyanosis and combined anomalies. The patient were classified into two groups; A and B according to the outcome after surgical repair. Group A included the patients who had a good postoperative outcome with or without mild complications such as wound disruption, or hydrothorax. Group B included the patients who had a poor outcome including hospital death and significant postoperative complications such as heart failure, low output syndrome, respiratory failure, hepatic failure and others. And the results were summarized as follows. 1. There were no significant differences in age, body surface area and aortic dimension among the group I, II, and III, but there were significant differences among groups in pulmonary arterial dimension, ACT[aortic cross clamping time], TBT [total bypass time], preoperative and postoperative ratio of systolic pressure of right and left ventricles [pre PRV/RV and post PRV/LV], and the size of Hegar dilator which passed through the RVOT postoperatively [p<0.05]. 2. In the group A and B, there were significant differences in pulmonary arterial dimension [group A:1.6$\pm$0.5 cm, group B:1.9$\pm$0.6 cm], ACT [group A:102.3$\pm$ 46.0 minute, group B:76.1$\pm$46.1 minute], TBT [group A:133.9$\pm$56.6 minute, group B:94.9$\pm$51.9 minute], pre PRV/LV [group A:1.06$\pm$0.24, group B:0.8$\pm$0.32], post PRV/LV [group A:0.58$\pm$0.18, group B:0.43$\pm$0.16].It has been concluded that postoperative prognosis of RVOT obstruction was influenced by pulmonary arterial dimension, ACT, TBT, severity of RVOT obstruction [pre PRV/LV] and post PRV/LV.

• Journal of Veterinary Clinics
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• v.19 no.1
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• pp.92-94
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• 2002

A male harbor seal (Phoca bitulina) about 10 years of age died. The seal was presented for necropsy in the Veterinary Teaching Hospital, Chungbuk National University in August 2001. The seal had been a concrete pool in zoo for 4 years. The exact duration of captivity was unknown. The carcass was weighed about 90 kg and was about 140 cm length. At necropsy, 2 adult filarioid worms were found in the right and left ventricles. The filaroid worms weren't found in the other organs. The parasites were slender white nematodes. A male nematode in the right ventricle was 14 cm long, and a female nematode in the left ventricle was 26 cm long in length. The parasites were identified as Dirofilaria immitis.

• Korean Journal of Head & Neck Oncology
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• v.37 no.1
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• pp.63-66
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• 2021

Supracricoid partial laryngectomy (SCPL) with cricohyoidoepiglottopexy (CHEP) or cricohyoidopexy (CHP) involves the removal of the whole thyroid cartilage, both true and false vocal cords, the ventricles, and the paraglottic spaces, sparing the cricoid cartilage, hyoid bone, and at least one functional and mobile cricoarytenoid unit. Reconstruction is performed by suturing of the cricoid cartilage up tightly to the hyoid bone, so trachea-releasing procedures are needed to prevent leakage at anastomosis site. In case of advanced tranglottic cancer invading tracheal tracheal wall, we need to perform additional circumferentrial circumferential tracheal wall resection. However, when we perform SCPL, circumferential resection of tracheal wall is limited because SCPL procedure itself needs releasing of tracheal length. We report a case of advanced transglottic cancer involving tracheal wall treated with induction chemotherapy and SCPL including tracheal wall resection with reconstruction of tracheal defect by sternocleidomastoid muscle flap covered with skin graft.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.1
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• pp.63-70
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• 2019

We aimed to propose a novel computational approach to predict the electromechanical performance of pre- and post-mitral valve cerclage annuloplasty (MVCA). Furthermore, we tested a virtual estimation method to optimize the left ventricular basement tightening scheme using a pre-MVCA computer model. The present model combines the three-dimensional (3D) electromechanics of the ventricles with the vascular hemodynamics implemented in a lumped parameter model. 3D models of pre- and post-MVCA were reconstructed from the computed tomography (CT) images of two patients and simulated by solving the electromechanical-governing equations with the finite element method. Computed results indicate that reduction of the dilated heart chambers volume (reverse remodeling) appears to be dependent on ventricular stress distribution. Reduced ventricular stresses in the basement after MVCA treatment were observed in the patients who showed reverse remodeling of heart during follow up over 6 months. In the case who failed to show reverse remodeling after MVCA, more virtual tightening of the ventricular basement diameter than the actual model can induce stress unloading, aiding in heart recovery. The simulation result that virtual tightening of the ventricular basement resulted in a marked increase of myocardial stress unloading provides in silico evidence for a functional impact of MVCA treatment on cardiac mechanics and post-operative heart recovery. This technique contributes to establishing a pre-operative virtual rehearsal procedure before MVCA treatment by using patient-specific cardiac electromechanical modeling of pre-MVCA.

• Korean Circulation Journal
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• v.48 no.12
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• pp.1081-1096
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• 2018

We reviewed the anatomical characteristics of the conduction system in the ventricles of human and ungulate hearts and then raised some questions to be answered by clinical and anatomical studies in the future. The ventricular conduction system is a 3-dimensional structure as compared to the 2-dimensional character of the atrial conduction system. The proximal part consisting of the atrioventricular node, the bundle of His and fascicles are groups of conducting cells surrounded by fibrous connective tissue so as to insulate from the underlying myocardium. Their location and morphological characters are well established. The bundle of His is a cord like structure but the left and right fascicles are broad at the proximal and branching at the distal part. The more distal part of fascicles and Purkinje system are linear networks of conducting cells at the immediate subendocardium but the intra-mural network is detected at the inner half of the ventricular wall. The papillary muscle also harbors Purkinje system not in the deeper part. It is hard to recognize histologically in human hearts but conducting cells as well as Purkinje cells are easily recognized in ungulate hearts. Further observation on human and ungulate hearts with myocardial infarct, we could find preserved Purkinje system at the subendocardium in contrast to the damaged system at the deeper myocardium. Further studies are necessary on the anatomical characteristics of this peripheral conduction system so as to correlate the clinical data on hearts with ventricular arrhythmias.

• BMB Reports
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• v.56 no.9
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• pp.520-525
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• 2023

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by cognitive decline. Several recent studies demonstrated that impaired adult neurogenesis could contribute to AD-related cognitive impairment. Adult subventricular zone (SVZ) neurogenesis, which occurs in the lateral ventricles, plays a crucial role in structural plasticity and neural circuit maintenance. Alterations in adult SVZ neurogenesis are early events in AD, and impaired adult neurogenesis is influenced by the accumulation of intracellular Aβ. Although Aβ-overexpressing transgenic 5XFAD mice are an AD animal model well representative of Aβ-related pathologies in the brain, the characterization of altered adult SVZ neurogenesis following AD progression in 5XFAD mice has not been thoroughly examined. Therefore, we validated the characterization of adult SVZ neurogenesis changes with AD progression in 2-, 4-, 8-, and 11-monthold male 5XFAD mice. We first investigated the Aβ accumulation in the SVZ using the 4G8 antibody. We observed intracellular Aβ accumulation in the SVZ of 2-month-old 5XFAD mice. In addition, 5XFAD mice exhibited significantly increased Aβ deposition in the SVZ with age. Next, we performed a histological analysis to investigate changes in various phases of adult neurogenesis, such as quiescence, proliferation, and differentiation, in SVZ. Compared to age-matched wild-type (WT) mice, quiescent neural stem cells were reduced in 5XFAD mice from 2-11 months of age. Moreover, proliferative neural stem cells were decreased in 5XFAD mice from 2 to 8 months of age. Furthermore, differentiations of neuroblasts were diminished in 5XFAD mice from 2-11 months of age. Intriguingly, we found that adult SVZ neurogenesis was reduced with aging in healthy mice. Taken together, our results revealed that impairment of adult SVZ neurogenesis appears with aging or AD progression.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.377-383
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• 2023

Purpose: There is increasing attention to the application of transcranial direct current stimulation (tDCS) for enhancing cognitive functions in subjects to aging, mild cognitive impairment (MCI), and Alzheimer's disease (AD). Despite varying treatment outcomes in tDCS which depend on the amount of current reaching the brain, there is no general information on the impacts of anatomical features associated with AD on tDCS-induced electric field. Objective: The objective of this study is to examine how AD-related anatomical variation affects the tDCS-induced electric field using computational modeling. Methods: We collected 180 magnetic resonance images (MRI) of AD patients and healthy controls from a publicly available database (Alzheimer's Disease Neuroimaging Initiative; ADNI), and MRIs were divided into female-AD, male-AD, female-normal, and male-normal groups. For each group, segmented brain volumes (cerebrospinal fluid, gray matter, ventricle, rostral middle frontal (RMF), and hippocampus/amygdala complex) using MRI were measured, and tDCS-induced electric fields were simulated, targeting RMF. Results: For segmented brain volumes, significant sex differences were observed in the gray matter and RMF, and considerable disease differences were found in cerebrospinal fluid, ventricle, and hippocampus/amygdala complex. There were no differences in the tDCS-induced electric field among AD and normal groups; however, higher peak values of electric field were observed in the female group than the male group. Conclusions: Our findings demonstrated the presence of sex and disease differences in segmented brain volumes; however, this pattern differed in tDCS-induced electric field, resulting in significant sex differences only. Further studies, we will adjust the brain stimulation conditions to target the deep brain and examine the effects, because of significant differences in the ventricles and deep brain regions between AD and normal groups.

• Journal of the Korean Society of Radiology
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• v.81 no.2
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• pp.302-309
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• 2020

Fabry disease is a rare X-linked metabolic disorder that is characterized by the accumulation of glycosphingolipids in various organs, resulting from the deficiency of alpha-galactosidase A. Cardiac involvement is relatively common; myocardial inflammation, left ventricular hypertrophy, and myocardial fibrosis secondary to abnormal lipid deposition in myocytes are often observed. Hence, the diagnosis of cardiac involvement is crucial for evaluating patient prognosis. Cardiac MRI is the standard technique for measuring the function, volume, and mass of the ventricles. It is also useful for myocardial tissue characterizations. The evaluation of native myocardial T1 values can facilitate early diagnosis of cardiac involvement, while measurements of left ventricular myocardial mass can be used to monitor treatment outcomes, in patients with Fabry disease. Consequently, cardiac MRI can provide useful information for diagnosing, monitoring, and treating patients with Fabry disease.

• Journal of the Korean Society of Radiology
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• v.85 no.2
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• pp.308-326
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• 2024

A comprehensive evaluation of cardiac function includes information in relation to cardiac output and systemic venous return. The heart is composed of four chambers: two atria and two ventricles, each with its own unique mechanical function. These four cardiac chambers, their valves, and the pulmonary circulation system are inter-related as they preload or afterload on each other. Cardiac dysfunction is a failure of global cardiac function, resulting in typical clinical manifestations. To investigate the underlying cause of cardiac dysfunction, a step-by-step evaluation of cardiac blood flow tracks is necessary. In this context, imaging markers showing details of the cardiac structures have an important role in assessing cardiac function. An image-based evaluation allows for investigation of function in terms of individual cardiac components. Evaluation of cardiac function using cardiac CT has recently been validated. This review aimed to discuss cardiac CT-based imaging markers for comprehensive and detailed cardiac function assessment.