• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.82-86
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• 1995

Using electrocardiography is a common method to diagnose heart disease, Modeling and simulation of activation process for the heart system is useful to understand electrocardiography. This paper proposes a two-dimensional cellular automata model for the activation process of the ventricles. The model represents the geometry of the ventricles by the ellipsoidal shape in two dimension. In the model, ventricles are divided into four layers, each of which has a set of cells with preassigned properties. The proposed model takes Into account the local orientation of the myocardial fibers and their distributed velocity, and refractory period. Simulation experiment is performed to measure activation potential for each cell in each layer within the ventricles.

• The Journal of Korean Medicine
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• v.17 no.2 s.32
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• pp.264-276
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• 1996

This study was carried out to evaluate the effect of Samhwasan on the Na-K-ATPase activity of heart muscle. The Na-K-ATPase activity was prepared from rabbit heart ventricles. Samhwasan markedly inhibited the Na- K - ATPase activity in a dose-dependent manner with an estimated $I_{50}$ of 0.56%. Hill coefficient was 1.70, indicating that the enzyme has more than one binding site for the Samhwasan. Inhibition of enzyme activity by Samhwasan increased as pretreatment time was prolonged. Inhibition by the drug was not affected by a change in enzyme protein concentration. Kinetic studies of substrate activation of the enzyme indicated classical noncompetitive inhibition, showing significant reduction in Vmax without a change in Km value. Inhibitory effect by Samhwasan was not altered by changes in concentration of $Mg^{2+}$, $Na^+$ or $K^+$, dithiothreitol. a sulfhydryl reducing reagent, did not protect the inhibition of Na-K-ATPase activity by Samhwasan combination of Samhwasan and ouabain showed a cumulative inhibition fashion. These results suggest that Samhwasan inhibits Na-K-ATPase activity of heart ventricles with an unique binding site different from that of ATP, $Mg^{2+}$, $Na^+$ or $K^+$ and ouabain.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.126-130
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• 1997

In the development of the totally implantable artificial heart (TAH), the information of the preload condition is important to ind appropriate condition or the automatic control of the heart. Our TAH configuration consists of two artificial ventricles, and brushless DC motor within actuator. The pressure between ventricles could indicate the preload condition during the TAH operation. If we can measure accurately inspite of the noise induced from TAH and environmental condition. We suggested integrating a feedback loop to remove an unexpected DC drift. NPI 19-series Nova sensor was used which could measure pressure in gas and liquid. This method and sensor enabled us to develop the pressure transducer compact so (that) the systems can be implanted with TAH into patient. This system has been verified in vitro and in vivo test. This results showed that the output waveform of this system was stable irrespective of animal condition.

• Korean Circulation Journal
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• v.48 no.11
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• pp.1014-1024
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• 2018

Background and Objectives: Intense exercise (IE) induced myocardial fibrosis (MF) showed contradictory findings in human studies, making the relationship between IE and the development of MF unclear. This study aims to demonstrate exercise induced MF is associated with cardiac damage, and inflammation is essential to the development of exercise induced MF. Methods: Sprague-Dawley rats were submitted to daily 60-minutes treadmill exercise sessions at vigorous or moderate intensity, with 8-, 12-, and 16-week durations; time-matched sedentary rats served as controls. Enzyme-linked immunosorbent assay (ELISA) was used to measure serum cardiac troponin I (cTnI) concentration. After completion of the exercise protocol rats were euthanized. Biventricular morphology, ultrastructure, and collagen deposition were then examined. Protein expression of interleukin $(IL)-1{\beta}$ and monocyte chemotactic protein (MCP)-1 was evaluated in both ventricles. Results: After IE, right but not left ventricle (LV) MF occurred. Serum cTnI levels increased and right ventricular damage was observed at the ultrastructure level in rats that were subjected to long-term IE. Leukocyte infiltration into the right ventricle (RV) rather than LV was observed after long-term IE. Long-term IE also increased protein expression of proinflammation factors including $IL-1{\beta}$ and MCP-1 in the RV. Conclusions: Right ventricular damage induced by long-term IE is pathological and the following inflammatory response is essential to the development of exercise induced MF.

• Biomolecules & Therapeutics
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• v.21 no.1
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• pp.84-88
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• 2013

High risk of cardiovascular diseases caused by existing PPAR-${\gamma}$ agonists such as rosiglitazone and pioglitazone has been recently reported. CKD-501 is a novel selective PPAR-${\gamma}$ agonist as a potential target to reduce cardiovascular risk in non-insulin dependent diabetes mellitus (NIDDM). In this study, We investigated potential cardiotoxicity of CKD-501 and compared its toxicity with that of rosiglitazone or pioglitazone using db/db mice. After 12-week repeated administration of CKD-501 at doses of 3, 10 and 30 mg/kg/day or rosiglitazone at doses of 10 and 30 mg/kg/day or pioglitazone at doses of 200 and 540 mg/kg/day, animals were sacrificed for investigation of potential toxicities. Diameters of left ventricles and areas of cardiomyocytes were measured. And lipid accumulation and apoptosis in heart muscle were examined by oil red O staining and TUNEL staining, respectively. Diameters of left ventricles were significantly increased in high dose treatment group of pioglitazone compared to control (p<0.05), while other groups showed a tendency for an increase. All test articles induced significantly the increase of area of cardiomyocytes in heart compared to control (p<0.01), in regular order as pioglitazone > CKD-501 ${\geq}$ rosiglitazone. However, lipid accumulation and apoptotic changes in heart were not observed in all dosing groups. Taken together, the myocardial cell hypertrophy of CKD-501 are relatively lower than that of pioglitazone and similar to rosiglitazone. And it is suggested that the myocardial cell hypertrophy of CKD-501 are less adverse in clinical use for the management of the NIDDM.

• Journal of Chest Surgery
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• v.12 no.3
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• pp.215-224
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• 1979

Corrected transposition of great arteries associated with dextrocardia [I.D.D.] is a very rare congenital cardiac malformation in which the atria and ventricles are in discordant relation, as are the ventricles and great arteries, but the aorta is to the right of the pulmonary artery. A 13 year old male patient who complained cyanosis and dyspnea on exertion for 8 years, was diagnosed as congenitally corrected transposition of great arteries associated with dextrocardia [I.D.D.], large ventricular septal defect, patent foramen ovale and pulmonary stenosis. He was operated on Nov. 22 1978. The ventricular septal defect was closed with Teflon felt and the pulmonary hypoplasia was corrected with Rastelli operation successfully. On 34th postoperative days, complete heart block was occurred and permanent epicardial pacemaker was implanted with good result.

• Journal of Yeungnam Medical Science
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• v.37 no.4
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• pp.345-348
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• 2020

Papillary fibroelastomas are the second most common primary cardiac tumor in adults. Over 80% of fibroelastomas occur on the cardiac valves, usually on the left side of the heart, while the remaining lesions are typically scattered throughout the atria and ventricles. Although the optimal timing for surgery is controversial and depends on tumor size and location, prompt surgical resection is warranted in patients at high risk of embolism. A tumor on the cardiac valve can be removed using the slicing excision technique without leaflet injury. Here we present two cases of papillary fibroelastomas occurring on the ventricular surface of the aortic valve and in the right ventricle.

• Journal of Chest Surgery
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• v.17 no.2
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• pp.197-204
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• 1984

The criss-cross, a term first used by Anderson and Ando , is a rare cardiac malformation in which the systemic and pulmonary blood streams cross at the atrioventricular level, without mixing. We have surgically experienced four cases of crossed atrioventricular connection, three concordant and one discordant, at Seoul National University Hospital from July 1982 to March 1984. The atrial situs, the atrioventriculoarterial connection, the spatial position of the ventricles, and associated cardiac anomalies were analyzed. We have performed right Blalock-Taussig shunt for case 1, modified Fontan operation for case 2, patch closure of VSD for case 3, and septation of common ventricle with primary closure of ASD for case 4. The relatively good postoperative results in these patients were gratifying and suggest that cardiac anomalies associated with this rare malformation can be successfully repaired without further risk. To our knowledge, this is the first report of surgical experience for criss-cross heart in the Korean literature.

• Journal of Biomedical Engineering Research
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• v.8 no.2
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• pp.161-170
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• 1987

A new type of motor-driven total artificial heart system with a rolloing-cylinder mechanism has been developed. The prototype system consists of a brushless DC motor inside of a rolling-cylinder, two arc shaped pusher-plate s, and two ventricles of smooth, seamless polyurethane sacs. The motor-driven pump has the advantages of being portable and quiet compared to the present air-driven pump. It can also be controlled more accurately. This rolling-cylinder type electromechanical pump has several structural advantages including small size and weight, as compared to other research groups' motor-driven pumps. The results of mock circulation tests confirm sufficient pump output capacity(cardiac output . 9 L/min, at aortic pressure'120mmHg, with heart rate . 120 BPM) for animal implantation of our prototype system.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1242-1246
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• 1997

Criss-cross heart which is a cardiac malformation caused by abnormal rotation of the ventricles early in embryonic development, is rare but a double outlet of right ventricle in priss-cross heart is very rare. We experienced a case of criss-cross heart which is situs solidus, concordant atrioventricular connection and double outlet of rig t ventricle with remote ventricular septal defect of perimembranous inlet type. A 4-years old female was diagnosed as a double outlet of right ventricle in criss-cross heart after echocardiography, cardiac catheterization and cardiac angiography. The surgical correction was a intraventricular reconstruction of left ventricular outflow with 314 circle of 20 mm Hemashield vascular graft from the ventricular septal defect to the aorta. The patient had a temporary atrioventricular block but was recovered uneventfully, and a postoperative echocardiogram showed no left ventricular outflow obstruction, no intracardiac shunt.