• 대한핵의학회지
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• 제33권3호
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• pp.273-281
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• 1999

목적: 우리는 비심장 수술 환자에서 수술전후의 심장사건의 위험도를 평가할 때 미국 순환기학회/미국 심장학회(이하ACC/AHA)에서 제시한 임상적 여러 지표에 더하여 심근관류 SPECT가 도움되는지 연구하였다. 대상 및 방법: 1997년에 비심장 수술을 시행한 118명(혈관수술 18, 비혈관수술 100)을 대상으로 수술 전에 휴식 T1-201/부하 Tc-99m MIBI 심근관류 SPECT를 시행하고 중한 심장사건과 경한 심장사건의 발생을 조사하였다. 임상적 지표, 운동능력, 수술 종류에 따라 분류한 것의 심장사건 예측률과 심근관류 SPECT 소견을 가역관류감소, 지속관류감소, 정상으로 나누었을 때 심장사건 예측률을 조사하였다. 임상적 지표들에 대해 심근관류 SPECT가 부가 효용이 있는지 다변량 로짓 회귀분석을 하였다. 결과: 심장사건은 전체 환자의 21%에서 발생하였으며 심근관류 SPECT에 가역적 심근관류 이상이 있는 경우에 심장사건의 발생빈도가 높았다. 임상적 분류와 수술 종류도 사건 발생을 예측할 수 있었으나 다변량 분석에 수술 종류(p=0.0018)와 심근관류 SPECT 소견(p=0.0001)이 유의한 예측지표이었다. 심근관류 SPECT 결과가 수술 종류에 따른 위험 예측을 더욱 계층화할 수 있었다. 결론: 비심장수술 환자에서 수술 종류에 더하여 심근관류 SPECT가 심장사건 발생을 예측하는 유용한 지표이었다.

• The Korean Journal of Physiology and Pharmacology
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• 제27권3호
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• pp.267-275
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• 2023

Cardiotoxicity, particularly drug-induced Torsades de Pointes (TdP), is a concern in drug safety assessment. The recent establishment of human induced pluripotent stem cell-derived cardiomyocytes (human iPSC-CMs) has become an attractive human-based platform for predicting cardiotoxicity. Moreover, electrophysiological assessment of multiple cardiac ion channel blocks is emerging as an important parameter to recapitulate proarrhythmic cardiotoxicity. Therefore, we aimed to establish a novel in vitro multiple cardiac ion channel screening-based method using human iPSC-CMs to predict the drug-induced arrhythmogenic risk. To explain the cellular mechanisms underlying the cardiotoxicity of three representative TdP high- (sotalol), intermediate- (chlorpromazine), and low-risk (mexiletine) drugs, and their effects on the cardiac action potential (AP) waveform and voltage-gated ion channels were explored using human iPSC-CMs. In a proof-of-principle experiment, we investigated the effects of cardioactive channel inhibitors on the electrophysiological profile of human iPSC-CMs before evaluating the cardiotoxicity of these drugs. In human iPSC-CMs, sotalol prolonged the AP duration and reduced the total amplitude (TA) via selective inhibition of I_Kr and I_Na currents, which are associated with an increased risk of ventricular tachycardia TdP. In contrast, chlorpromazine did not affect the TA; however, it slightly increased AP duration via balanced inhibition of I_Kr and I_Ca currents. Moreover, mexiletine did not affect the TA, yet slightly reduced the AP duration via dominant inhibition of I_Ca currents, which are associated with a decreased risk of ventricular tachycardia TdP. Based on these results, we suggest that human iPSC-CMs can be extended to other preclinical protocols and can supplement drug safety assessments.

• The Korean Journal of Physiology and Pharmacology
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• 제23권5호
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• pp.295-303
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• 2019

A heart simulator, UT-Heart, is a finite element model of the human heart that can reproduce all the fundamental activities of the working heart, including propagation of excitation, contraction, and relaxation and generation of blood pressure and blood flow, based on the molecular aspects of the cardiac electrophysiology and excitation-contraction coupling. In this paper, we present a brief review of the practical use of UT-Heart. As an example, we focus on its application for predicting the effect of cardiac resynchronization therapy (CRT) and evaluating the proarrhythmic risk of drugs. Patient-specific, multiscale heart simulation successfully predicted the response to CRT by reproducing the complex pathophysiology of the heart. A proarrhythmic risk assessment system combining in vitro channel assays and in silico simulation of cardiac electrophysiology using UT-Heart successfully predicted drug-induced arrhythmogenic risk. The assessment system was found to be reliable and efficient. We also developed a comprehensive hazard map on the various combinations of ion channel inhibitors. This in silico electrocardiogram database (now freely available at http://ut-heart.com/) can facilitate proarrhythmic risk assessment without the need to perform computationally expensive heart simulation. Based on these results, we conclude that the heart simulator, UT-Heart, could be a useful tool in clinical medicine and drug discovery.

• Journal of Chest Surgery
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• 제50권3호
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• pp.171-176
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• 2017

Background: In elderly patients who have atrial fibrillation (AF), surgical ablation of the arrhythmia during cardiac surgery may be challenging. Despite the reported advantages of ablating AF with the Cox maze procedure (CMP), the addition of the CMP may complicate other cardiac operations. We evaluated the effect of the CMP in elderly patients concurrent with other cardiac operations. Methods: From October 2007 to December 2015, we enrolled 27 patients aged >70 years who had AF and who underwent the CMP concurrently with other cardiac operations. The mean preoperative additive European System for Cardiac Operative Risk Evaluation score was $8{\pm}11$ (high risk). Results: Only 1 hospital death occurred (4%). The Kaplan-Meier method showed a high 5-year cumulative survival rate (92%). At mean follow‐up of 51 months, 23 patients (89%) had sinus rhythm conversion. The postoperative left atrial dimensions did not significantly differ between the 8 patients who had reduction plasty for giant left atrium ($53.4{\pm}7.5cm$) and the 19 patients who did not have reduction plasty ($48.7{\pm}5.7cm$). Conclusion: In patients aged >70 years, concurrent CMP may be associated with a high rate of sinus rhythm conversion without increased surgical risk, despite the added complexity of the main cardiac procedure.

• Journal of Chest Surgery
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• 제41권6호
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• pp.718-723
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• 2008

배경: 최근 20년간 수술적인 기법, 마취 기술, 심폐기 운용, 중환자실 관리의 발전으로 심장수술의 사망률과 합병증은 상당히 감소하였지만 심장수술이 중추신경계에 상당한 위험 요소가 되는 것은 널리 알려진 바이다. 이 연구는 두경부 MRA를 통해 심장 수술 대상자에서 불현성 뇌혈관계 질환의 유병률과 두경부 MRA 상에서 비정상적인 소견을 보인 환자의 치료 방침의 변화를 알아보고자 하였다. 대상 및 방법: 2005년 10월부터 2008년 6월까지 두경부 MRA 촬영에 동의한 107명의 심장수술 예정자(21세에서 83세까지의 연령분포를 보인 남자 71명과 여자 36명)를 대상으로 하였다. 이 환자들 중에서 신경학적인 고위험군의 비율과 그 환자들의 치료 방침의 변화를 관찰하였다. 결과: 신경학적으로 고위험군 환자의 비율은 15.7% (17예)였으며, 이중 11예는 허혈성 심질환, 6예는 판막 질환이였으며, 이 중 2예의 환자만이 이전에 신경학적인 병력이 있었다. 14명(13.1%)의 환자에서 치료 방침에 변화가 있었다. 결론: 심장수술 대상자에 있어 불현성 뇌혈관계 질환은 비교적 높은 것으로 생각되며, 이를 밝히는 데 있어 두경부 MRA가 의미 있는 것으로 생각된다.

• Tuberculosis and Respiratory Diseases
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• 제62권6호
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• pp.516-522
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• 2007

연구 목적 및 방법: 수술 후 폐 합병증은 심장 합병증보다 흔하고 술 후 입원기간 연장 및 사망률을 높이는 중요한 합병증이다. 최근 NSQIP에서 수술 후 중요한 폐 합병증인 폐렴과 호흡 부전의 위험 인자를 제시하였으나, 복잡하고 폐기능이나 동맥혈 가스 분석 같은 기본적인 검사 소견은 고려되지 않은 면이 있다. 또한 국내 연구에서는 수술 후 폐 합병증의 위험 인자가 명확치 않다. 이에 전향적 연구로 수술 후 폐 합병증의 위험 인자를 알아보고자 하였다. 가천의대 길병원에서 호흡기내과로 의뢰된 환자 199명을 대상으로 수술 후 폐 합병증(폐렴, 호흡 부전, 무기폐, 흉수)이 생긴 환자군과 그렇지 않은 군의 위험 인자를 비교하였다. 결 과: 22명(11.1%)에서 수술 후 폐 합병증이 발생하였고, 흉수(13명), 호흡 부전(6명), 폐렴(4명), 무기폐(2명) 순이었다. 단변량 분석에서 폐 합병증의 유의한 위험 인자는 높은 cardiac risk index, 수술 전 후 nasogastric tube 사용, 흉부/상복부 수술, 3시간 이상의 마취 시간, 술 전 11.0 g/dL 이하의 헤모글로빈으로 나타났으며, 다변량 로지스틱 회귀 분석 상 독립적인 위험 인자는 응급 수술(OR 10.306, 95% CI=1.508-70.438, p=0.017), 높은 심장 위험도(OR 16.454, 95% CI=2.720-99.521, p=0.002), 수술 종류(OR 3.814, 95% CI=1.016-14.313, p=0.047)로 나타났다.

• 대한종양외과학회지
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• 제14권2호
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• pp.102-107
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• 2018

Purpose: Cardiotoxicity is a serious late complication of breast cancer treatment. Individual treatment risk of specific drugs has been investigated. However, studies on the evaluation of the composite risk of chemotherapeutic agents are limited. Methods: We retrospectively analyzed the medical records of breast cancer patients who received adjuvant treatment and had available serial echocardiography results. Patients were assigned to subgroups based on chemotherapy containing anthracyclines (A), anthracyclines and taxanes (A+T), and radiotherapy (RT). The development of cardiac disease and serial ejection fraction (EF) were reviewed. EF decline up to 10% from baseline was considered grade 1 cardiotoxicity and EF decline >20% or absolute value <50% was considered grade 2 cardiotoxicity. The most recent medical records and echocardiography results over 1 year of chemotherapy completion were also reviewed. Late cardiotoxicity was defined as a lack of recovery of EF decline or aggravated EF decline from baseline. Results: In total, 123 patients were evaluated. A small reduction in EF was observed after chemotherapy in both chemotherapy groups. There were no significant differences between groups A and A+T in EF decline following chemotherapy. We could not find any differences in composite risk between the chemotherapy groups and the RT group during follow-up. Late cardiotoxicity was seen in 15.45% of patients. During follow-up, three patients were diagnosed with dilated cardiomyopathy. Conclusion: There was no significant composite risk elevation following adjuvant treatment of breast cancer. However, late cardiotoxicity was considerable and further research in this direction is necessary.

• Journal of Chest Surgery
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• 제16권1호
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• pp.18-29
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• 1983

Thirty-two patients with a cyanotic cardiac malformations having more complex intracardiac defects than ones in a tetralogy of Fallot underwent complete intracardiac repairs in a-full-year period from July 1981 to June 1982. Twenty-two patients [68.8%] died within 30 days after surgery: Transposition of the great arteries, seven of 10 patients; Double-outlet right ventricle, four of 6 patients; Tricuspid atresia, four of 6 patients; Single ventricle, all of 4 patients; Pulmonary atresia, two of 3 patients; Double-outlet left ventricle, none of 2 patients; and Truncus arteriosus, one of a single patient. All deaths occurred with a low cardiac output syndrome or a failed off-bypass, and they were almost always accompanied with other grave postoperative complications. The complex intracardiac anatomy itself was one of the risk factors by making a complete intracardiac repair of the defects difficult in a small heart. The reconstruction of the right ventricular outflow carried a difficulty in balancing an adequate relief of the obstruction with an avoidance of making too much pulmonary valvular insufficiency as well. On the other hand, the presence of an elevated pulmonary arterial pressure and a high pulmonary vascular resistance was also the factors affecting the postoperative surviv als. The importance of detailed knowledge of intracardiac anatomy and hemodynamics from the careful preoperative evaluation of the patient was discussed along with the necessity of technical refinement of the correction.

• 센서학회지
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• 제21권1호
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• pp.39-45
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• 2012

Recently the convergence of healthcare technology is used for daily life healthcare monitoring. Cardiac arrhythmia is presented by the state of the heart irregularity. Abnormal heart's electrical signal pathway or heart's tissue disorder could be the cause of cardiac arrhythmia. Fatal arrhythmia could put patient's life at risk. Therefore arrhythmia detection is very important. Previous studies on the detection of arrhythmia in various ECG analysis and classification methods had been carried out. In this paper, an ECG signal processing techniques to detect abnormal ECG based on DTW minimum accumulation distance through the template matching for normalized data and variable threshold method for ECG R-peak detection. Signal processing techniques able to determine the occurrence of normal ECG and abnormal ECG. Abnormal ECG detection algorithm using DTW minimum accumulation distance method is performed using MITBIH database for performance evaluation. Experiment result shows the average percentage accuracy of using the propose method for Rpeak detection is 99.63 % and abnormal detection is 99.60 %.

• 대한영상의학회지
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• 제83권1호
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• pp.3-27
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• 2022

심장 전산화단층촬영은 비약적인 기술발전과 다양한 연구 결과를 바탕으로 심혈관위험 계층화와 치료 결정을 위한 관상동맥 질환의 진단과 예후 평가성능이 입증되었다. 전산화단층촬영 관상동맥조영술은 폐쇄성 관상동맥 질환에 대한 음성 예측도가 높아서 침습적 혈관조영술의 빈도를 줄일 수 있는 관상동맥 질환 관련 검사의 관문으로 부상했지만, 진단특이도가 상대적으로 낮다. 하지만 심장 전산화단층촬영을 이용한 분획혈류예비력과 심근관류를 분석하여 관상동맥 질환의 혈역학적 유의성을 확인하는 기능적 평가를 통해 그 한계를 극복할 수 있다. 최근에는 이를 보다 객관적이고 재현 가능하도록 인공지능을 접목하는 연구들이 활발히 진행되고 있다. 본 종설에서는 심장 전산화단층촬영의 기능적 영상화 기법들에 대해 알아보고자 한다.