• Journal of Yeungnam Medical Science
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• 제24권2호
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• pp.197-205
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• 2007

Background : The occurrence of atrial fibrillation after ablation of atrial flutter is clinically important. We investigated variables predicting this evolution in ablated patients without a previous atrial fibrillation history. Materials and Methods : Thirty-six patients (Male=28) who were diagnosed as atrial flutter without previous atrial fibrillation history were enrolled in this study. Group 1 (n=11) was defined as those who developed atrial fibrillation after atrial flutter ablation during 1 year follow-up. Group 2 (n=25) was defined as those who has not occurred atrial fibrillation during same follow-up term. Echocardiogram was performed to all patients. We measured left atrial size, left ventricle end diastolic and systolic dimension, ejection fraction and left atrial volume index before and after ablation of atrial flutter. The differences of each variables were compared and analyzed between two groups. Results : The preablation left ventricular ejection fraction (preLVEF) and postablation left ventricular ejection fraction (postLVEF) are $54{\pm}14%$, $56{\pm}13%$ in group 1 and $47{\pm}16%$, $52{\pm}13%$ in group 2. The differences between each two groups are statistically insignificant ($2.2{\pm}1.5$ in group 1 vs $5.4{\pm}9.8$ in group 2, p=0.53). The preablation left atrial size (preLA) and postablation left atrial size (postLA) are $40{\pm}4mm$, $41{\pm}4mm$ in group1 and $44{\pm}8mm$, $41{\pm}4mm$ in group 2. The atrial sizes of both groups were increased but, the differences of left atrial size between two groups before and after flutter ablation were statistically insignificant ($0.6{\pm}0.9mm$ in group 1 vs $-3.8{\pm}7.4mm$ in group 2, p=0.149). The left atrial volume index before flutter ablation was significantly reduced in group 1 than group 2 ($32{\pm}10mm^3/m^2$, $35{\pm}10mm^3/m^2$ in group 1 and $32{\pm}10mm^3/m^2$, $29{\pm}8mm^3/m^2$ in group 2, p<0.05). Conclusion : The difference between left atrial volume index before and after atrial flutter ablation is the robust predictor of occurrence of atrial fibrillation after atrial flutter ablation without previous atrial fibrillation.

• 한국임상수의학회지
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• 제27권4호
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• pp.435-439
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• 2010

6살된 암컷 불테리어종 개 (체중 17 kg)가 운동 불내성과 실신증상으로 내원하였다. 진단검사를 통해 특발성 심근확장증에 의한 심방조동과 완전 방실차단 증례로 진단되었다. 환자는 심근증에 대한 일반적인 치료와 dofetilide를 포함한 항부정맥 치료를 통해 11개월간 관리되었다. 하지만 환자는 갑작스런 심장마비로 폐사하였다.

• Journal of Chest Surgery
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• 제48권1호
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• pp.67-69
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• 2015

This is a report of a biatrial cardiac myxoma in a young man with a 10-month history of exertional dyspnea and palpitation. The echocardiogram revealed biatrial myxoma prolapsing through the mitral and tricuspid valves during diastole. All cardiac chambers were enlarged and dysfunctional. The electrocardiogram revealed a rapid ventricular response with atrial flutter rhythm. The masses were resected and diagnosed as myxoma by a histological examination. The follow-up echocardiogram revealed significant improvement in ventricular function and reduction in the cardiac chambers' volume. There was no evidence of myxoma recurrence. The most probable cause of the patient's heart failure was considered to be tachycardia-induced cardiomyopathy.

• Journal of Chest Surgery
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• 제14권1호
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• pp.49-59
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• 1981

This is one case report of surgically treated partial atrioventricular canal. The 22 year-old male patient had no definitive history of frequent respiratory infection and cyanosis in his early childhood. Since his age of 7 years, dyspnea was manifested on exertion. First appearance of congestive heart failure was at his age of 16 years old. The physical examination revealed that the neck veins were distended and heaving of precordium. A thrill was palpable on the left 3rd-4th intercostal space extending from the sternal border toward the apex and Grade IV/VI systolic ejection murmur was audible on it. Neither cyanosis nor clubbing was noted. Liver was palpable about 5 finger breadths. Chest X-ray revealed increased pulmonary vascularity and severe cardiomegaly (C-T ratio = 74%). EKG revealed LAD, clockwise rotation, LVH and trifascicular block. Echocardiogram showed paradoxical ventricular septal movement, narrowed left ventricular outflow tract and abnormal diastolic movement of the anterior leaflet of mitral valve. Right heart catheterization resulted in large left to right shunt (Qp : Qs = 5.7: 1), ASD and moderate pulfllonary hypertension. Finally, left ventriculogram revealed typical goose neck appearance of left ventrlcalar outflow tract. On Oct. 10, 1980, open heart surgery was performed. Operative findings were: 1. Large primum defect ($6{\times}5$ Cm in diameter) 2. Cleft on the anterior leaflet of mitral valve. 3. The upper portion of ventricular septum was descent but no interventricular communication. 4. Downward attachment of the atrioventricular valves on the ventricular muscular septum. 5. Medium sized secumdum defect ($2{\times}1$ Cm in diameter). The cleft was repaired with 4 interrupted sutures. The primum defect was closed with Teflon patch and the secundum defect was closed with direct suture closure. Postoperatively atrial flutter-fibrillation in EKG and Grade U/VI apical systolic murmur were found. The postoperative course was uneventful and discharged on 29th postoperative day in good general conditions.

• Industrial Engineering and Management Systems
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• 제12권4호
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• pp.380-388
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• 2013

Large variation in electrocardiogram (ECG) waveforms continues to present challenges in defining R-wave locations in ECG signals. This research presents a procedure to extract the R-wave locations by forward-backward (FB) algorithm and classify the arrhythmic beat conditions by using RR intervals. The FB algorithm shows forward and backward searching rules from QRS onset and eliminates lower-amplitude signals near the baseline using a statistical process control concept. The proposed algorithm was trained the optimal parameters by using MIT-BIH arrhythmia database (MITDB), and it was verified by actual Holter ECG signals from a local hospital. The signals are classified into normal (N) and three arrhythmia beat types including premature ventricular contraction (PVC), ventricular flutter/fibrillation (VF), and second-degree heart block (BII) beat. This work produces 98.54% accuracy in the detection of R-wave location; 98.68% for N beats; 91.17% for PVC beats; and 87.2% for VF beats in the collected Holter ECG signals, and the results are better than what are reported in literature.

• Journal of Chest Surgery
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• 제25권6호
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• pp.672-677
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• 1992

This is a clinical review of the results from electric cardioversion and pharmacological therapy used in our hospital for reverting cardiac arrythmia in patients with mitral valve surgery between Jan. 1990 and Jun. 1991. Of 62 evaluated patients, 16 patients had regular sinus rhythm and the other 46 had arrhythmias [42; atrial fibrillation 1; atrial flutter 1; premature ventricular contraction] preoperatively. In 2 of patients with sinus rhythm, atrial fibrillation newly developed after surgery and was converted into sinus rhythm soon by intravenous administration of digoxin. Remaining 14 patient resumed sinus rhythm spontaneously. In patients with preoperative arrythmia, 3 patients reverted into sinus rhythm from atrial fibrillation by electric cardioversion at operative field, 1 patient by lidocain and mexiletine, 4 patients by combined use of digoxin and verapamil, 4 patients by 2 times of oral quinidine and 9 patient by long term use of oral amiodarone. Throughout this consecutive trials of anti-arrhythmic drugs and electric cardioversion, Conversion into normal sinus rhythm occurred in 48% of patients with arrhythmia developed after mitral valve surgery.

• Journal of Mechanical Science and Technology
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• 제15권5호
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• pp.613-622
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• 2001

Interaction of blood flow and leaflet behavior in a bileaflet mechanical heart valve was investigated using computational analysis. Blood flows of a Newtonian fluid and a non-Newtonian fluid with Carreau model were modeled as pulsatile, laminar, and incompressible. A finite volume computational fluid dynamics code and a finite element structure dynamics code were used concurrently to solve the flow and structure equations, respectively, where the two equations were strongly coupled. Physiologic ventricular and aortic pressure waveforms were used as flow boundary conditions. Flow fields, leaflet behaviors, and shear stresses with time were obtained for Newtonian and non-Newtonian fluid cases. At the fully opened phase three jets through the leaflets were found and large vortices were present in the sinus area. At the very final stage of the closing phase, the angular velocity of the leaflet was enormously large. Large shear stress was found on leaflet tips and in the orifice region between two leaflets at the final stage of closing phase. This method using fluid-structure interaction turned out to be a useful tool to analyze the different designs of existing and future bileaflet valves.

• Progress in Superconductivity
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• 제7권1호
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• pp.28-35
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• 2005

We propose a method to measure atrial arrhythmias (AA) such as atrial fibrillation (Afb) and atrial flutter (Afl) with a SQUID magnetocardiograph (MCG) system. To detect AA is one of challenging topics in MCG. As the AA generally have irregular rhythm and atrio-ventricular conduction, the MCG signal cannot be improved by QRS averaging; therefore a SQUID MCG system having a high SNR is required to measure informative atrial excitation with a single scan. In the case of Afb, diminished f waves are much smaller than normal P waves because the sources are usually located on the posterior wall of the heart. In this study, we utilize an MCG system measuring tangential field components, which is known to be more sensitive to a deeper current source. The average noise spectral density of the whole system in a magnetic shielded room was $10\;fT/{\surd}Hz(a)\;1\;Hz\;and\;5\;fT/{\surd}Hz\;(a)\;100\;Hz$. We measured the MCG signals of patients with chronic Afb and Afl. Before the AA measurement, the comparison between the measurements in supine and prone positions for P waves has been conducted and the experiment gave a result that the supine position is more suitable to measure the atrial excitation. Therefore, the AA was measured in subject's supine position. Clinical potential of AA measurement in MCG is to find an aspect of a reentry circuit and to localize the abnormal stimulation noninvasively. To give useful information about the abnormal excitation, we have developed a method, separative synthetic aperture magnetometry (sSAM). The basic idea of sSAM is to visualize current source distribution corresponding to the atrial excitation, which are separated from the ventricular excitation and the Gaussian sensor noises. By using sSAM, we localized the source of an Afl successfully.

• Journal of Chest Surgery
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• 제31권4호
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• pp.393-397
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• 1998

25세된 말기 심부전 환자에게 한국에서는 최초로 광배근을 이용한 심근 성형술이 성공적으로 실시되었다. 환자는 약 심근수축력이 30%인 상태로 94년과 96년에 한차례씩 심부전으로 입원한 적이 있으며 수술직전 임상상태는 NYHA functional class III 였다. 간조직 검사상 만성 활동성 간염으로 판명되었으며 환자는 간염 항원이 양성으로 심장이식대상에서 제외되었다. 1996년 7월 30일 좌측 광배근을 이용하여 심근 성형술을 실시하였다. 측와위로 광배근을 박리한후 자극전극을 설치하였으며 흉골 정중 절개로 심장을 노출한 후 광배근으로 심장을 감싸주고 심근 전극을 설치한 후 좌상부 복부에 심장근육자극기를 설치하였다. 총 수술시간은 약 7시간 30분이 소요되었으며 환자는 수술후 일시적인 심방 조동(atrial flutter)을 보여 심도자실에서 동율동으로 환원시킨 것외에는 특별한 합병증은 없었다. 환자는 수술후 6주째 자극기의 빈도가 1:4인 상태에서 퇴원하였으며 통원치료중 1:1로 근육훈련을 마친 후 현재는 수술후 6개월째 자극빈도가 1:4인 상태에서 외래 추적중이다. 심초음파상 수축력의 차이는 없으나 환자의 임상 활동은 수술전보다 양호해진 상태이다.

• Journal of Chest Surgery
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• 제40권12호
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• pp.811-816
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• 2007

배경: 선천성 심 질환에 동반된 심실성 혹은 상심실성 부정맥은 심기형에 대한 수술에 병행하여 적극적인 수술적 치료를 하는 것이 바람직하다. 본 연구에서는 선천성 심 질환에 동반된 부정맥의 양상 및 부정맥 수술의 중기 성적을 알아보았다. 대상 및 방법: 1998년 6월부터 2006년 6월까지 선천성 심 질환 및 동반 부정맥에 대한 수술이 동시에 시행된 43명의 환자의 임상 자료를 후향적으로 분석하였다. 결과: 수술 시 환자의 연령은 4세에서 75세(중간 값: 52세)이었다. 가장 흔한 심 질환은 심방 중격 결손(23예)이었으며, 기타 엡스타인 기형(5예), 과거 심방-폐동맥 연결형 Fontan 수술을 받은 기능적 단심증(3예)의 순이었다. 부정맥의 유형으로는 심방 조동-세동이 37예로 가장 많았고, 간헐적이면서 지속적이지 않은 심실성 빈맥이 2예, 기타 여러 유형의 상심실성 부정맥이 4예이었다. 심방 조동-세동 및 일부 상심실성 부정맥에 대하여 양심방 maze 술식이 18건(변형 Cox maze III 술식: 5예, 우심방 maze와 폐정맥 냉동 분리술: 13예), 우심방 maze 술식이 18건 시행되었으며, 짧은 병력의 심방 조동 만을 가진 4명의 환자에서는 하대정맥-삼첨 판막 협부 냉동 절제 만이 시행되었다. 또한 심실성 빈맥을 가진 2명의 환자들은 우심실 유출로 냉동 절제술이 시행되었고, 엡스타인 기형에 동반된 방실 결절 회귀성 빈맥에 대해서는 결절 주변 냉동 절제가 시행되었다. 수술 사망 및 부정맥 수술로 인한 합병증은 없었다. 수술 후 추적기간은 1개월에서 95.2개월(중간 값: 23.8개월)이었으며, 추적 기간 중 1명의 환자가 수술 후 5개월째 전격성 간염으로 사망하였다. 전체 환자의 동율동 회복률은 수술 직후 및 수술 후 $3{\sim}6$개월에 각각 79% 및 81%이었다(양심방 maze 군: 72% 및 83%, 우심방 maze 군: 77%, 77%). 양심방 maze 술식 및 우심방 maze 술식을 받은 환자 군에서 각각 1명씩 동방 결절 기능 부전으로 인공 심박동기를 삽입하였다. 결론: 선천성 심기형에 동반된 부정맥에 대한 수술적 치료는 안전하게 이루어 질 수 있으며, 우수한 중기 성적을 보인다.