• 대한의용생체공학회:의공학회지
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• 제29권5호
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• pp.343-347
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• 2008

Thermal conductivity, thermal diffusivity were measured in the atrium of a swine heart. Radiofrequency (RF) catheter ablation in an atrium has rapidly emerged at the treatment of symptomatic reentrant arrhythmia associated with accessory pathway or Atrioventricular (AV) node conduction. The thermal properties of an atrium are definitely necessary for these treatments because, in thermal treatments, conductivity and diffusivity are significant factors in the relationship between the applied RF power and the resulting atrium temperature rise. Thermal properties were measured using a self-heated thermistor probe. Thermistor probes were inserted into the tissue of interest and were used to supply heat within the tissue as well as to monitor the temperature rise in the tissue. The measurements were performed at temperatures of 25, 37, $50^{\circ}C$. Atrium thermal conductivity ranged from 5.17$\pm$0.12 mW/cm$^{\circ}C$ at $25^{\circ}C$ to 5.33$\pm$0.08 mW/cm$^{\circ}C$ at $37^{\circ}C$. Atrium thermal diffusivity ranged from 0.00132$\pm$0.00007$cm^2$/sec at $25^{\circ}C$ to 0.00138$\pm$0.00003 $cm^2$/sec at $50^{\circ}C$. This paper also present the thermal property comparison of both chambers of a heart (ventricle and atria).

• 한국임상수의학회지
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• 제18권4호
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• pp.452-454
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• 2001

A two-month-old female Yorkshire terrier was referred to the Veterinary Teaching Hospital, College of Veterinary Medicine, Kyungpook national University. The patient was presented with a history of dyspnea, cough, exercise intolerance and abdominal distension, but she was appetence. In physical examination the puppy was coughed on slight tracheal compression. Rectal temperature, pulse and respiratory rate were normal, and grade 3/6 systolic murmur heard at the left heart base. The murmur was crescendo-decrescendo. Electrocardiography showed sinus arrhythmia, right-ventricular hypertrophy pattern, and right axis deviation. Thoracic radiography revealed cardiomegaly, bulging of the main pulmonary artery, and enlarged left side heart. Abdominal radiography revealed abdkominal distention. Echocardiography showed hypertrophy of right ventricle and turbulence in the pulmonary artery in parasternal oblique view. Subvalvular pulmonic stenosis was diagnosis based upon the clinical signs, physical examination, electrocardiography, radiography and echocardiography. We treated the patient with furosemide, enalapril and $\beta$-blocker. After the clinical signs of cough, abdominal distension and dyspnea were disappeared, she was on just $\beta$-blocker for prevention of occurrence of congestive heart failure. Now she was recovered her health, and she is not on any medication.

• Biomolecules & Therapeutics
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• 제17권1호
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• pp.1-11
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• 2009

Since the Committee for Proprietary Medicinal Products (CPMP) of the European Union issued in 1997 a "points to consider" document for the assessment of the potential for QT interval prolongation by non-cardiovascular agents to predict drug-induced torsades de pointes (TdP), the QT liability has become the critical safety issue in the development of pharmaceuticals. As TdP is usually linked to delayed cardiac repolarization, international guideline (ICH S7B) has advocated the standard repolarization assays such as in vitro IKr (hERG current) and in vivo QT interval, or in vitro APD (as a follow up) as the best biomarkers for predicting the TdP risk. However, the recent increasing evidence suggests that the currently used above biomarkers and/or assays are not fully predictive for TdP, but also does not address potential new druginduced TdP due to the selective disruption of hERG protein trafficking to the cell membrane or VT and/or VF with QT shortening. There is, therefore, an urgent need for other surrogate markers or assays that can predict the proarrhythmic potential of drug candidate. In this review, we provide an ideal pre-clinical strategy to predict the potentials of QT liability and lethal arrhythmia of the drug candidates with recent issues in this field in mind, not at the expense of discarding therapeutically innovative drugs.

• Journal of Chest Surgery
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• 제25권12호
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• pp.1563-1569
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• 1992

From Jan. 1981 to Dec. 1991, we had treated 25 patients with congenital coronary art-eriovenous fistulas [CAVF] in Seoul National University Hospital. A retrospective review was made to delineate the course and the management of CAVF and to clarify the role of surgical treatment. Fifteen patients were male and 10 were female with The mean age of 17.4 years[from 3 months to 58 years]. The most frequent symptom was dyspnea on exertion[56%]. Other symptoms were angina and palpitation. Sixty-eight percent of the patients were symptomatic. Fifty-three percent of patients less than 20 years old were symptomatic and 100% of patients over 20 years old were symptomatic. Three patients had multiple CAVFs. The fistula drained into the right ventricle in 13, pulmonary artery in 9, left ventricle in 4, right atrium in 2, and left atrium in 1. Thirteen patients had other associated cardiac lesions. The mean pulmonary-to-systemic blood flow[Qp /Qs] in the isolate CAVF group was 2.19. All patients were operated on to correct the fistulas and other associated cardiac lesions. All patients were followed from 1 month to 11 years without late death. Postoperative complication rate was 24% -significant arrhythmia [3], recurred CAVF[1], psychosis[1], pneumonia [1]. Symptomatic improvement was evident postoperatively. Below 20 years old, 94% of patients were asymptomatic, but above 20 years old, symptoms persisted in 25%. In summary, early elective repair of CAVF is indicated in all patients because of higher complication rate and frequent persistent symptoms in older patients.

• Journal of Chest Surgery
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• 제26권7호
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• pp.526-531
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• 1993

Sixty-one consecutive patients with coronary artery bypass graft for myocardial revascularization were retrospectively reviewed to analyze various pattern of postoperative complication and death during hospital stay from Nov. 1988 to Oct. 1992. Fortytwo of the patients were male and nineteen female. The mean age was 56 and 51 years in male and female. Preoperative diagnosises were unstable angina in 14 of patients, stable angina in 28, postmyocardial infarction state in 15, and state of failed percutaneous transluminal coronary angioplasty in 4. 141 stenosed coronary arteries were bypassed with use of 20 pedicled internal mammary artery and 124 reversed saphenous vein grafts. Postoperative complications and perioperative death were as follows: 1. Of 61 patients undergoing operation, peri and postoperative over all complication occured in 15 patients [ 25% ]; newly developed myocardial infarction in 4, intractable cardiac arrhythmia including atrial fibrillation and frequent ventricular premature contraction in 3, bleeding from gastrointestinal tract in 2, persistent vegetative state as a sequele of brain hypoxia in 1, wound necrosis in 1, left hemidiaphragmatic palsy in 3 and poor blood flow through graft in 2. 2. Operative mortality was 8%[5 patients]. 3 out of these died in operating room; 1 patient by bleeding from rupture of calcified aortic wall, 1 by air embolism through left atrial vent catheter, 1 by low cardiac output syndrome. 2 patients died during hospital stay; 1 by acute respiratory distress syndrome with multiuple organ failure, 1 by brain death after delayed diagnosis of pericardial tamponade.

• Journal of Chest Surgery
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• 제24권12호
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• pp.1185-1191
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• 1991

The clinical and pathological analysis of solitary pulmonary nodules were estimated in 35 patients with nodules who were surgically resected at the Dept. of Thoracic and Cardiovascular Surgery of Chonnam National University Hospital from July 1978 to Aug. 1989. The results were as follows: 1. Mean age of patients was 43.5 years extending from 11 years to fi7 years old and male to female ratio was 6: l. 2. Preoperative symptoms were complained of dull pain in the chest, cough, hemoptysis and general weakness in 69% of patients. 3. The histopathologic findings of surgically resected nodules showed benign nodule in 51% and malignancy 49%. The most frequent diseases were granuloma[67%] in benign nodules and squamous cell carcinoma[76%] in malignancy. In topographical region of nodules in the lung, benign granuloma was more prevalent in upper lobes, while malignancy was slightly more frequent in lower lobes. 4. The incidence of malignancy by age was extremely rare in patients with less than 35 years old, but in greater than 35 years of age, malignancy comprised up to 67% of patients. 5. Complications of thoracotomy were minor bleedings, wound infections and chest pain not to be required any reoperation except one patient died of sudden onset of arrhythmia after pneumonectomy.

• Journal of Chest Surgery
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• 제27권3호
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• pp.202-208
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• 1994

We reviewed 30 patients with tetralogy of Fallot who had underwent transannular patch reconstruction of the right ventricular outflow tract from January 1990 to May 1993. The patients were divided into two groups according to the approaching pattern for the corrective surgery: 12 patients[aged 11 months to 4 years; mean age, 2.3 years] in transatrial group who were repaired by transatrial-transpulmonary approach; 18 patients[aged 13 months to 6 years; mean age, 3.2 years] in transventricular group who were repaired by transventricular approach. The incidence of postoperative right bundle branch block was not statistically different between two groups. With follow up from 3 months to 32 months after operation, none in transatrial group revealed a remnant RVOT stenosis over 50mmHg or tricuspid regurgitation more than grade II with 2D-echocardiography, but two cases[7.7%] in transventricular group revealed these complications. Early postoperative death was 4 cases[13.3%] which all belonged to transventricular group. In conclusion successful repair of tetralogy of Fallot can be accomplished in most patients by transatrial-transpulmonary approach and we can anticipate better results by this approach in terms of postoperative right ventricular function and arrhythmia than conventional transventricular approach.

• Journal of Chest Surgery
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• 제50권1호
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• pp.41-43
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• 2017

A 38-year-old female patient with a history of tetralogy of Fallot repair at 10 years of age underwent pulmonary valve replacement with a mechanical prosthesis, tricuspid annuloplasty, and right ventricular outflow tract cryoablation due to pulmonary regurgitation, tricuspid regurgitation, and multiple premature ventricular contractions with sustained ventricular tachycardia. After surgery, she had an uneventful postoperative course with arrhythmia monitoring. She was discharged without incident, and a follow-up Holter examination showed a decrease in the number of ventricular ectopic beats from 702 to 41.

• 대한수의학회지
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• 제47권1호
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• pp.85-89
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• 2007

A case of multicentric high grade T cell lymphoma is reported in a 5-year-old male Maltese dog with generalized lymphadenopathy. The dog showed depression, anorexia, blindness, jaundice, arrhythmia, and hematuria for 8 months. Complete blood count and chemistry profile revealed anemia and increased alanine transferase, alkaline phosphatase, total bilirubin, and total cholesterol. Grossly, most of lymph nodes, spleen, and liver were enlarged and neoplastic masses were occupied in these tissues. Histologically, massive accumulation of small noncleaved neoplastic lymphocytes with high mitotic figures was observed in all lymph nodes and spleen. Infiltration of neoplastic lymphocytes was also noted in the lung, liver, kidney, eye, skin, muscle, and bone marrow of femur. Immunohistochemistry revealed that tumor cells were CD3-positive and but CD79a-negative, consistent with T-cell lineage. In our best knowledge, this is the first report of multicentric lymphoma clarified the origin of tumor cells in Korea.

• Biomolecules & Therapeutics
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• 제14권1호
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• pp.19-24
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• 2006

Atrial chambers serve as mechanosensory systems during the haemodynamic or mechanical disturbances, which initiates arrhythmia. Atrial myocytes, lacking t-tubules, have two functionally separate sarcoplasmic reticulums (SRs): those at the periphery close to the surface membrane, and those at the cell interior (center) not associated with the membrane. To explore possible role of fluid pressure (FP) in the regulation of atrial local $Ca^{2+}$ signaling we investigated the effect of FP on subcellular $Ca^{2+}$ signals in isolated rat atrial myocytes using confocal microscopy. FP was applied to whole area of single myocyte with pressurized automatic micro-jet (200-400 $mmH_2O$) positioned close to the cell. Application of FP enhanced spontaneous occurrences of peripheral and central $Ca^{2+}$ sparks with larger effects on the peripheral release sites. Unitary properties of single sparks were not altered by FP. Exposure to higher FP often triggered longitudinal $Ca^{2+}$ wave. These results suggest that fluid pressure may directly alter excitability of atrial myocytes by activating $Ca^{2+}$-dependent ionic conductance in the peripheral membrane and by enhancing spontaneous activation of central myofilaments.