• Journal of Chest Surgery
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• 제24권11호
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• pp.1081-1089
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• 1991

Atrial fibrillation is characterized by beat to beat irregularity of shape, size, conduction time and polarity. The mechanism of atrial fibrillation can be explained by so called "Multiple wavelet theory". The adverse effect of atrial fibrillation is the decrease of cardiac output by absence of atrial kick[10 ~ 15%] and the possibility of thrombosis in the left atrium which is dangerous to develop the thromboembolism is increased. The present study was designed to assess the effect of overdrive pacing on the suppression of recurring of atrial fibrillation after open heart surgery and the results were summarized as follows: 1. There were no significant differences of factors between converting patients and non-converting patients to normal sinus rhythm by electric cardioversion after open heart surgery. 2. Among converting patients to normal sinus rhythm, there were no significant differences of factors between study group and control group. 3. Cardiothoracic Ratio on the preoperative chest film was significantly larger in the patients of recurring atrial fibrillation within 72hrs than in the patients of maintaining normal sinus rhythm. [61.7$\pm$ 1.4% vs 67.7$\pm$2.4%, p=0.03] 4. There was a significant difference of suppressive effects between overdrive pacing group and control group among recurred cases until 24, 48, and 72hours [Fisher`s exact test ; p=0.037, p=0.076, p=0.53, respectively] 5. There was a difference of the delay of recurring of atrial fibrillation between study group and control group among recurred cases within 72 hours.[53.4$\pm$6.9hr vs. 19.3$\pm$3.8 hr, p<0.01] We think that the overdrive pacing may suppress the natural pacemaker and the converted normal sinus rhythm is maintained longer than control group during critical immediate postoperative period.ve period.

• 대한의용생체공학회:의공학회지
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• 제38권3호
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• pp.123-128
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• 2017

Background and aims: The KCNQ1 S140G mutation involved in $I_{ks}$ channel is a typical gene mutation affecting atrial fibrillation. However, despite the possibility that the S140G gene mutation may affect not only atrial but also ventricular action potential shape and ventricular responses, there is a lack of research on the relationship between this mutation and ventricular fibrillation. Therefore, in this study, we analyzed the correlation and the influence of the KCNQ1 S140G mutant gene on ventricular fibrillation through computer simulation studies. Method: This study simulated a 3-dimensional ventricular model of the wild type(WT) and the S140G mutant conditions. It was performed by dividing into normal sinus rhythm simulation and reentrant wave propagation simulation. For the sinus rhythm, a ventricular model with Purkinje fiber was used. For the reentrant propagation simulation, a ventricular model was used to confirm the occurrence of spiral wave using S1-S2 protocol. Results: The result showed that 41% shortening of action potential duration(APD) was observed due to augmented $I_{ks}$ current in S140G mutation group. The shortened APD contributed to reduce wavelength 39% in sinus rhythm simulation. The shortened wavelength in cardiac tissue allowed re-entrant circuits to form and increased the probability of sustaining ventricular fibrillation, while ventricular electrical propagation with normal wavelength(20.8 cm in wild type) are unlikely to initiate re-entry. Conclusion: In conclusion, KCNQ1 S140G mutation can reduce the threshold of the re-entrant wave substrate in ventricular cells, increasing the spatial vulnerability of tissue and the sensitivity of the fibrillation. That is, S140G mutation can induce ventricular fibrillation easily. It means that S140G mutant can increase the risk of arrhythmias such as cardiac arrest due to heart failure.

• Journal of Chest Surgery
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• 제26권12호
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• pp.909-914
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• 1993

Complete and optimal visualization of the mitral apparatus is a prerequisite for accurate repair or replacement of the mitral valve. A vertical left atriotomy just posterior to the interatrial groove is the most commonly used approach. However,exposure can be difficult under certain circumstances,such as small left atrium or reoperation. Other approaches have been advocated to deal with this difficult situations. We used an extended transseptal approach in 10 patients and good clinical results and excellent educational effects were obtained. The extended transseptal approach combines two semicircular atrial incisions circumscribing the tricuspid and mitral annuli anteriorly and superiorly,allowing exposure of the mitral valve by deflecting the ventricular side using stay sutures. The right atrium is opened anteriorly along the atrioventricular sulcus. The atrial septum is incised vertically through the fossa ovalis. Right atrial and septal incisions are joined at the superior end of the interatrial septum and extended across the dome of the left atrium to the left atrial appendage. The mitral valve was replaced in all 10 patients. Four of 10 patients had other simultaneous valve procedure: one had aortic valve replacement: 2 underwent tricuspid annuloplasty: 1 had aortic valve replacement and tricuspid annuloplasty. There was no hospital death and complication. Among the 5 patients who had atrial fibrillation preoperatively,4 had atrial fibrillation postoperatively,1 converted to sinus rhythm. The five patients who were in normal sinus rhythm preoperatively remained in sinus rhythm after replacement. A review of our results with this approach confirms the efficacy and safty of this method. So we recommanded this approach for routine mitral valve procedure,especially difficult situations,such as a small left atrium or the redo operation.

• Journal of Chest Surgery
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• 제25권12호
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• pp.1404-1415
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• 1992

To understand the factors influencing Atrial fibrillation and embolism in mitral valve surgery and prevent their risk, we have reviewed our 324 patients who underwent mitral valve surgery from Fev. 1982 to May 1992. Age, disease duration, lesion type, left ventricular function and left atrial dimension were chosen as preoperative factors influencing the incidence of atrial fibrillation and embolism and their postoperative course, The number and type of replaced valve, site of atriotmy, LA obliteration, ACT and use of Defibrillator were chaser. as operative factors influencing postoperative rhythm change and postop emb-olization. The results of analyses were as follows 1. The incidence of preoperative atrial fibrillation, systemic embolism and LA throbmus was 63. 6%, 10.56% and 19.8% relatively. 2. The preoperative factors of atrial fibrillation onset was old age, prolonged symptom duration, stenotic lesion, lager LAD and lower ejection fraction. In the preoperative systemic embolism preoperative factors were old age, female, stenotic lesion. The left atrial thrombus found more commonly in patients with atrial fibrillation, old age, prolonged symptom duration, stenotic lesion and low ejection fraction. 3. The preoperative atrial fibriation persisted postoperatively in 165[50.9%] and converted to normal sinus rhythm in 50[15.4%]. The preoperative normal sinus rhythm per-eisted in 100[31%] and atrial fibrillation was occured postoperatively in 9[2.7%]. The prolonged symptom duration was the preoperative factor of persist atrial fibrillation. 4. Among 95 long term follow-up patients, atiral fibrillation was continued in 59[60%]. Conversion to normal sinus rhythm was more common significantly in left atriotomy and bileaflet valve replacement. 5. There were 12 patients who had postoperative embolism. Female, persist atrial fibrillation, no LA olbiteration and tilting disc monocusp valve were considered as possible factors influencing postoperative embolism but was impossible to analyse their statistical significance due to small sample size. So we have concluded that the patients with above risk factors need anticoagulant and early surgical intervention. Left atriotomy with minimal atrial injury, left auricular obliteration and bileaflet valve replacement may be needed to reduce postoperative atrial fibrillation persist and embolism.

• Journal of Chest Surgery
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• 제24권11호
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• pp.1149-1153
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• 1991

A modified procedure for the operative management of the corrected transposition of the great arteries with ventricular septal defect and pulmonary stenosis or atresia was performed in 4 patients. (age ; 18 months-9 years). The operation consists of a venous switch procedure (Senning), intraventricular baffling directing the blood flow from the morphologic left ventricle into the aorta via ventricular septal defect through the right ventriculotomy, and insertion of valved conduit between the morphologic right ventricle and the pulmonary artery. All the four patients had large non-restrictive ventriular septal defects and no evidence of significant mitral valve regurgitation. Both ventricles were well-developed. Three cases had pulmonary atresia, and the remainder had severe subpulmonic stenosis. Postperatively, all patients showed no findings of systemic or pulmonary venous obstruction withnormal sinus rhythm. One patient died of sepsis due to infection by Methicillin-resistant S. aureus on the thirteenth postoperative day. Follow-up is done on the survivors, and all of them are dong well with regular sinus rhythm, with their functional class I or II at 2 to 8 months after the operation.

• 전기학회논문지
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• 제66권7호
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• pp.1072-1077
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• 2017

Mean-reverting analysis refers to a way of estimating the underlining tendency after new data has evoked the variation in the equilibrium state. In this paper, we propose a new method to interpret the specular portraits of Premature Ventricular Contraction(PVC) arrhythmia by applying K-means unsupervised learning algorithm on electrocardiogram(ECG) data. Aiming at this purpose, we applied a mean-reverting model to analyse Heart Rate Variability(HRV) in terms of the modified poincare plot by considering PVC rhythm as the component of disrupting the homeostasis state. Based on our experimental tests on MIT-BIH ECG database, we can find the fact that the specular patterns portraited by K-means clustering on mean-reverting HRV data can be more clearly visible and the Euclidean metric can be used to identify the discrepancy between the normal sinus rhythm and PVC beats by the relative distance among cluster-centroids.

• Journal of Chest Surgery
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• 제46권2호
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• pp.98-103
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• 2013

Background: Atrial fibrillation (AF) is a common complication in elderly patients with atrial septal defect (ASD). The purpose of this study was to examine the efficacy of the maze procedure in these patients. Materials and Methods: Between February 2000 and May 2011, 46 patients underwent the maze procedure as a concomitant operation with ASD closure. Three patients who underwent a right-sided maze were excluded, and one patient was lost to follow-up. The mean follow-up duration was $3.2{\pm}2.5$ years. Electrocardiography was performed 1 month, 3 months, 6 months, and 1 year after surgery, and checked annually after that. Results: AF persisted in 4 patients after surgery. One year after surgery, among 38 patients, 55.3% remained in sinus rhythm without antiarrhythmic drugs. However, when including the patients who took antiarrhythmic drugs, 92.1% were in sinus rhythm. Freedom from AF recurrence at 3 months, 6 months, 1 year, 2 years, 3 years, and 5 years after surgery were $97.4{\pm}2.6$, $94.4{\pm}3.8$, $91.2{\pm}4.9$, $87.8{\pm}5.8$, $79.5{\pm}7.6$, and $68.2{\pm}12.4$, respectively. There was no early mortality after operation. Conclusion: Concomitant treatment with the maze procedure and ASD closure is safe and effective for restoring the sinus rhythm.

• Journal of Chest Surgery
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• 제41권6호
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• pp.710-717
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• 2008

배경: 심방 세동은 뇌혈관 사고, 말초 동맥 색전증 같은 합병증과 많은 연관이 되어 있고 무엇보다도 만성적으로 이 부정맥을 가지고 있는 환자들은 가슴 두근거림과 깜짝 놀램 증상 등이 있어서 환자의 삶의 질을 많이 떨어뜨린다. 이 논문의 목적은 본 교실에서 시행해 온 변형된 Maze술 식의 중장기 결과를 내고 이에 영향을 주는 요인들을 조사하는데 있다. 대상 및 방법: 2001년 6월부터 2007년 2월까지 88명을 대상으로 조사를 하였고 모두 본 교실에서 냉동절제(cryoabation)을 이용한 변형된 Maze술 식을 받았다. 냉동절제로 폐정맥 부분을 분리하는 방법에 따라 두 그룹으로 나누었고, 첫 번째 그룹은 58명(group 1, Lee-Maze, n=58)으로 우측 폐정맥은 절개 및 봉합으로 좌측 폐정맥은 냉동절제로 분리하였고, 두 번째 그룹은 30명(group 2, Cryo-Maze, n=30)으로 좌측 및 우측 폐정맥 부분 모두를 냉동 절제로만 시행하였다. 술 후 퇴원 시 동율동 전환 여부와 추적 관찰에서의 동율동 유지 및 심방 세동의 재발, 그리고 마지막 추적 관찰시의 심장리듬을 알아보았다. 결과: 모든 환자의 추적 관찰 기간은 평균 $44.3{\pm}19.2$개월이었고, 퇴윈 시 리듬은 group 1 (Lee-Maze)에서는 동율동이 72.4%에서 나타났고 group 2 (Cryo-Maze)에서는 66.7%가 관찰되었다. 마지막 추적 관찰 시 리듬은 group 1에서 81%, group 2에서는 60%에서 심방 세동이 재발하지 않았다. 그리고 Kaplan-Meier방법으로 분석을 해 보았을 때 심방 세동 재발로부터의 자유률(% Free from AF)은 group 1에서 1년 86.5%, 5년 80%였고, group 2에서는 1년 70%, 5년 51%였다. 결론: 냉동 절제를 이용한 변형된 Maze술은 단순하고 효과적인 수술이지만, 표준적 MazeIII 술 보다는 다소 낮은 성공률을 보이고 있다. 냉동 절제를 이용한 변형된 방법은 수술 시간이 단축될 수 있으나 성공률을 높이기 위해서는 더욱 많은 연구와 노력이 필요할 것으로 사료된다.

• Clinical and Experimental Pediatrics
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• 제46권2호
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• pp.195-197
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• 2003

저자들은 비경화성 심근증을 동반한 두 자녀와 기질적 질환이 없이 발생한 동기능 장애 증후군 환자를 경험하였기에 문헌 고찰과 함께 가족성 동기능 장애 증후군 1례를 보고하는 바이다.

• Journal of Chest Surgery
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• 제18권4호
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• pp.623-634
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• 1985

One of the most widely recognized problems in patients with TGA [transposition of the great arteries] after the Senning operation is the occurrence of arrhythmias. From June 1982 through October 1984, 22 patients, 11 with "simple" and 11 with "complex" TGA, underwent correction of TGA by a modification of the Senning operation designed to avoid dysrhythmias. 16 were males and 6 females, with ages ranging from 3 months to 27 months. [mean age 10.8 months] 7 patients [31.8%], 1 with simple TCA and 6 with complex TGA, died in the early post-operative period. The operative mortality was 9.1% in "simple" TGA, and 54.9% in "complex" TGA. There were 4 late deaths but only one of these patients died of a dysrhythmia as a possible factor. The standard ECG [Electrocardiography] checked preoperatively showed sinus rhythm in 17 [77.3%], 1 AV block in 5 [22.7%]. In 22 patients studied postoperative 1st day, the incidence of arrhythmias was 63.6%, with significant incidence compared with preoperative study. [P<0.05]. But, in 15 patients studied postoperatively at intervals from 1 month to 26 months, the incidence of arrhythmias was 26.7%, with no significant incidence compared with preoperative study [P>0.1]. Our results indicate that a modified Senning operation may reduce the frequency of surgically induced arrhythmias. The mean frontal plane P-wave axis also revealed significant deviation to the right side [P<0.05], compared with preoperative study. These findings raise the possibility that what has been called sinus rhythm postoperatively may have a different origin and conduction sequence from normal. But the rhythm seems to be functionally similar.rhythm seems to be functionally similar.