• Journal of Chest Surgery
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• v.43 no.6
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• pp.725-728
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• 2010

Rhabdomyoma is the most common benign cardiac neoplasm in neonates. Most patients with rhabdomyoma experienced spontaneous regression. Yet some of them need surgical therapy because of hemodynamic problems of the heart such as arrhythmia, outflow tract obstruction and valvular dysfunction. We found multiple masses in both ventricles on the patient's fetal echocardiogram. Heart failure caused by severe left ventricular outflow tract obstruction quickly presented after birth. The mass interfering with the outflow tract was resected via the transaortic approach at the first day of birth. Postoperative echocardiography showed complete release of the outflow tract obstruction. He was discharged on the postoperative day 8. During the 3 years of follow up, we found that the sizes of the remnant masses had gradually decreased.

• Genomics & Informatics
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• v.10 no.2
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• pp.106-109
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• 2012

Pulse rate is known to be related to diverse phenotypes, such as cardiovascular diseases, lifespan, arrhythmia, hypertension, lipids, diabetes, and menopause. We have reported two genomewide significant genetic loci responsible for the variation in pulse rate as a part of the Korea Association Resource (KARE) project, the genomewide association study (GWAS) that was conducted with 352,228 single nucleoride polymorphisms typed in 8,842 subjects in the Korean population. GJA1 was implied as a functionally causal gene for pulse rate from the KARE study, but lacked evidence of replication. To re-evaluate the association of a locus near GJA1 with pulse rate, we looked up this signal in another GWAS conducted in a Health Examinee-shared cohort of 3,703 samples. Not only we were able to confirm two pulse rate loci (1q32.2a near CD46 and 6q22.13c near LOCL644502) identified in the KARE GWAS, we also replicated a locus (6q22.31c) near GJA1 by the lookup in the Health Examinee GWAS. Considering that the GJA1-encoded protein is a major component of cardiac gap junctions, a functional study might be necessary to validate its genuine molecular biological role in the synchronized contraction of the heart.

• Journal of Chest Surgery
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• v.9 no.2
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• pp.265-270
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• 1976

Implantation of a permanent pacemaker is a widely accepted procedure for the patient with complete heart block.As a result of these device, the prognosis for patients with Adams-Stokes syndrome caused by complete A-V block and other cardiac arrhythmia have become much more optimistic. Permanent pacemaker implantation by means of a transvenous approach has made the operative risk much less and the procedure simpler. However, a number of complications have been reported in the literature regarding transvenous endocardial pacemaker implantation during the last a decade. The patient presented in this paper is a 26-year old girl who was implanted with a permanent pacemaker at 14 years of age because of a congenital A-V block. Following first exchange of pulse generator, the electrode (lead) was fractured, so that by the pulse generator, a change to the transvenous technique of implantation was made, After this, there were episodes of recurrent wound infection on three occasions, even though the site of pulse generator implantation was exchanged to the contralateral side of chest wall, massive doses of antibiotics were administered and sensitivity tests for coagulase positive staphylococcal infection were performed. Though there was no definite evidence of blood stream infection by blood culture, we decided not to use the transvenous technique and not to implant the pulse generator in the chest wall because the venous system and the entire anterior chest wall appeared to be diseased or contaminated by virulent pyogenic organisms. Finally this intractable systemic and local wound infection was successfully controlled by myocardial lead implantation via a subxiphoid approach and implantation of the pulse generator far down in the abdominal wall. The causes and routes of recurrent wound infection and possible blood born infection in this particular patient are still obscure. We strongly believe that myocardial pacemaker implantation is much safer than transvenous endocardial pacemaker implantation & myocardial pacemaker implantation is a definite method for controlling such an intractable wound infection. following transvenous pacemaker implantation.

• Journal of Chest Surgery
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• v.18 no.1
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• pp.97-103
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• 1985

During the period of seven years from Jan. 1976 to Jan. 1983, one hundred cases of pulmonary tuberculous residual lesions were resected at the Department of Thoracic Surgery, Paik Hospital in Seoul, Korea. During the period of this study, 1764 patients were admitted with the diagnosis of pulmonary and/or pleural tuberculosis in the medical and surgical department as a primary or associated conditions. Among these 1764 patients, one hundred selective cases were operated. The results were as follows; l. Extents of the disease by the predominant clinical pictures were: totally destroyed lung; 18, destroyed lobe; 6, cavitary lesion with or without positive sputum; 35, bronchiectasis; 7, bronchostenosis with atelectasis; 2, empyema with or without BPF; 20, pleural thickening; 4, tuberculoma; 3, bullous cyst with tuberculosis; 5 cases, or per cent [Table 1]. 2. Male and female ratio was 1.2:1 or 55 and 45 per cent. Age distribution ranged 15 and 55 with average of 33 years [Table 2]. 3. Type of procedures were: pleuropneumonectomy; 15, pneumonectomy; 25, lobectomy; 37, bilobectomy; 6, lobectomy plus segmentectomy; 3, pleurectomy; 14 cases, or percent, Site of resections were: right; 58 and left; 42 cases, or per cent [Table 3]. 4. Incidence of complications were 10 per cent and the mortality was 4 per cent. The causes of morbidity were analyzed. The main causes of death were pulmonary insufficiency; 2, cardiac arrhythmia; 1, and hepatic insufficiency; 1 case or per cent [Table 4]. 5. Pathologic examinations of the resected pulmonary and pleuropulmonary lesions were observed by gross specimen, correlating with the pre-operative indications of the disease [Fig. 1, 2, 3, 4, 5, 6].>br> 6. Anti-tuberculous chemotherapy was done for 6 to 18 months, post-operatively, in 80 patients. Of these 49 cases were need medication for 12 months [Table 5]. Except the four operative mortality and a case of post-operative recurrent buberculosis under medication, all the other 95 cases are well in activity and free from the disease at the moment.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.1
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• pp.75-82
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• 2017

The effects of acepromazine on human ether-$\grave{a}$-go-go-related gene (hERG) potassium channels were investigated using whole-cell voltage-clamp technique in human embryonic kidney (HEK293) cells transfected with hERG. The hERG currents were recorded with or without acepromazine, and the steady-state and peak tail currents were analyzed for the evaluating the drug effects. Acepromazine inhibited the hERG currents in a concentration-dependent manner with an $IC_{50}$ value of $1.5{\mu}M$ and Hill coefficient of 1.1. Acepromazine blocked hERG currents in a voltage-dependent manner between -40 and +10 mV. Before and after application of acepromazine, the half activation potentials of hERG currents changed to hyperpolarizing direction. Acepromazine blocked both the steady-state hERG currents by depolarizing pulse and the peak tail currents by repolarizing pulse; however, the extent of blocking by acepromazine in the repolarizing pulse was more profound than that in the depolarizing pulse, indicating that acepromazine has a high affinity for the open state of the channels, with a relatively lower affinity for the closed state of hERG channels. A fast application of acepromazine during the tail currents inhibited the open state of hERG channels in a concentration-dependent. The steady-state inactivation of hERG currents shifted to the hyperpolarized direction by acepromazine. These results suggest that acepromazine inhibits the hERG channels probably by an open- and inactivated-channel blocking mechanism. Regarding to the fact that the hERG channels are the potential target of drug-induced long QT syndrome, our results suggest that acepromazine can possibly induce a cardiac arrhythmia through the inhibition of hERG channels.

• Journal of Biomedical Engineering Research
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• v.38 no.6
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• pp.285-290
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• 2017

Radiofrequency catheter ablation is the interventional therapy that be employed to eliminate cardiac tissue caused by arrhythmias. During radiofrequency catheter ablation, The thrombus can occur at electrode tip if the temperature of tissue and electrode is excess $100^{\circ}C$. To prevent this phenomenon, we investigated numerical model of electrode for radiofrequency catheter ablation considering saline irrigation and temperature-controlled radiofrequency system. The numerical model is based on coupled electric-thermal-flow problem and solved by COMSOL Multiphysics software. The results of the models show that the dimensions of the thermal lesion are increased if the flow rate of the saline irrigation and the set temperature are increased. The surface width characterized to determine the thermal lesion isn't need to measure in temperature-controlled radiofrequency system due to convective heat transfer by saline irrigation at tissue-electrode interface.

• Quality Improvement in Health Care
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• v.10 no.2
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• pp.216-231
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• 2003

Objectives: To develop a model that predicts a death probability of acute myocardial infarction(AMI) patient, and to evaluate a performance of hospital services using the developed model. Methods: Medical records of 861 AMI patients in 7 general hospitals during 1996 and 1997 were reviewed by two trained nurses. Variables studied were risk factors which were measured in terms of severity measures. A risk model was developed by using the logistic regression, and its performance was evaluated using cross-validation and bootstrap techniques. The statistical prediction capability of the model was assessed by using c-statistic, $R^2$ as well as Hosmer-Lemeshow statistic. The model performance was also evaluated using severity-adjusted mortalities of hospitals. Results: Variables included in the model building are age, sex, ejection fraction, systolic BP, congestive heart failure at admission, cardiac arrest, EKG ischemia, arrhythmia, left anterior descending artery occlusion, verbal response within 48 hours after admission, acute neurological change within 48 hours after admission, and 3 interaction terms. The c statistics and $R^2$ were 0.887 and 0.2676. The Hosmer-Lemeshow statistic was 6.3355 (p-value=0.6067). Among 7 hospitals evaluated by the model, two hospitals showed significantly higher mortality rates, while other two hospitals had significantly lower mortality rates, than the average mortality rate of all hospitals. The remaining hospitals did not show any significant difference. Conclusion: The comparison of the qualities of hospital service using risk-adjusted mortality rates indicated significant difference among them. We therefore conclude that risk-adjusted mortality rate of AMI patients can be used as an indicator for evaluating hospital performance in Korea.

• Journal of Chest Surgery
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• v.24 no.3
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• pp.310-321
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• 1991

Between April 1986 and September 1990, 34 patients with a single or dominant right ventricle underwent modified Fontan procedure for definite palliation in Seoul National University Children`s Hospital. Their age at operation ranged from 8 months to 14 years [Mean 5.5 years]. The ventricular chamber was solitary and of indeterminate trabecular pattern in 6 patients. 28 patients had posteriorly located rudimentary chamber, all of which were trabecular pouches having no communication with outlet septum. The patterns of atrioventricular connection were common inlet[9], double inlet [11], left atrioventricular valve atresia [12] and right atrioventricular valve atresia with L-loop [2]. Pulmonary outflow tracts were atretic in 7 patients and stenotic in 26 patients. Major associated anomalies included anomalous systemic venous drainage [15], dextrocardia [12] and total anomalous pulmonary venous connection[3]. Shunt operations were previously performed in 13 patients and pulmonary artery banding and atrial septectomy in 1 patients. Surgery included intraatrial baffling in 26 patients, bidirectional cavopulmonary shunt in 13 patients, atrioventricular valve obliteration in 3 patients and atrioventricular valve replacement in 3 patients. Central venous pressure measured postoperatively at intensive care unit ranged from 18cm H2O to 28cm H2O [mean 23.2cm H2O]. Hospital mortality was 35.3% [12/34], all died out of low output syndrome. Suspected causes of low output syndrome include ventricular dysfunction [8], hypoplastic or tortuous pulmonary artery [2] and elevated pulmonary vascular resistance [2]. 19 patients had 31 major complications including low output syndrome [18], arrhythmia [4], acute renal failure [3] and respiratory failure [3]. Mortality rate was significantly higher in the groups receiving intraatrial baffling and AV valve replacement respectively [p<0.05]. 20 patients were followed up postoperatively with the mean follow-up period 15.0$\pm$11.6 months. There were no late death and follow-up catheterization was performed in 10 patients. Mean right atrial pressure was 15.4$\pm$6.8mmHg and ventricular contraction was reasonable in all but one case. Thus, Fontan principle can be applied successfully to all the patients with complex cardiac anomaly of single ventricle variety and better results can be anticipated with judicious selection of patient and improvement of postoperative care.

• Journal of Chest Surgery
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• v.45 no.1
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• pp.30-34
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• 2012

Background: The long-term results of homografts used in systemic circulation are controversial. We assessed the long-term results of using a cryopreserved homograft for an aortic root or aorta and its branch replacement. Materials and Methods: From June 1995 to January 2010, 23 patients (male:female=15:8, $45.4{\pm}15.6$ years) underwent a homograft replacement in the aortic position. The surgical techniques used were aortic root replacement in 15 patients and aortic graft interposition in 8 patients. Indications for the use of a homograft were systemic vasculitis (n=15) and complicated infection (n=8). The duration of clinical follow-up was $65{\pm}58$ months. Results: Early mortality occurred in 2 patients (8.7%). Perioperative complications included atrial arrhythmia (n=3), acute renal failure (n=3), and low cardiac output syndrome (n=2). Late mortality occurred in 6 patients (26.1%). The overall survival rates at 5 and 10 years were 66.3% and 59.6%, respectively. Six patients (28.6%) suffered from homograft-related complications. Conclusion: Early results of homograft replacement in aortic position were favorable. However, close long-term follow-up is required due to the high rate of homograft-related events.

• BMB Reports
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• v.53 no.10
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• pp.545-550
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• 2020

Combination therapy using chloroquine (CQ) and azithromycin (AZM) has drawn great attention due to its potential anti-viral activity against SARS-CoV-2. However, clinical trials have revealed that the co-administration of CQ and AZM resulted in severe side effects, including cardiac arrhythmia, in patients with COVID-19. To elucidate the cardiotoxicity induced by CQ and AZM, we examined the effects of these drugs based on the electrophysiological properties of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) using multi-electrode arrays. CQ treatment significantly increased the field potential duration, which corresponds to prolongation of the QT interval, and decreased the spike amplitude, spike slope, and conduction velocity of hESC-CMs. AZM had no significant effect on the field potentials of hESC-CMs. However, CQ in combination with AZM greatly increased the field potential duration and decreased the beat period and spike slope of hESC-CMs when compared with CQ monotherapy. In support of the clinical data suggesting the cardiovascular side effects of the combination therapy of CQ and AZM, our results suggest that AZM reinforces the cardiotoxicity induced by CQ in hESC-CMs.