• The Korean Journal of Physiology and Pharmacology
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• v.21 no.1
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• pp.37-44
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• 2017

Regulation of vascular smooth muscle cell (VSMC) phenotype plays an essential role in many cardiovascular diseases. In the present study, we provide evidence that $kr{\ddot{u}}ppel$-like factor 8 (KLF8) is essential for tumor necrosis factor ${\alpha}$ ($TNF{\alpha}$)-induced phenotypic conversion of VSMC obtained from thoracic aorta from 4-week-old SD rats. Stimulation of the contractile phenotype of VSMCs with $TNF{\alpha}$ significantly reduced the VSMC marker gene expression and KLF8. The gene expression of KLF8 was blocked by $TNF{\alpha}$ stimulation in an ERK-dependent manner. The promoter region of KLF8 contained putative Sp1, KLF4, and $NF{\kappa}B$ binding sites. Myocardin significantly enhanced the promoter activity of KLF4 and KLF8. The ectopic expression of KLF4 strongly enhanced the promoter activity of KLF8. Moreover, silencing of Akt1 significantly attenuated the promoter activity of KLF8; conversely, the overexpression of Akt1 significantly enhanced the promoter activity of KLF8. The promoter activity of SMA, $SM22{\alpha}$, and KLF8 was significantly elevated in the contractile phenotype of VSMCs. The ectopic expression of KLF8 markedly enhanced the expression of SMA and $SM22{\alpha}$ concomitant with morphological changes. The overexpression of KLF8 stimulated the promoter activity of SMA. Stimulation of VSMCs with $TNF{\alpha}$ enhanced the expression of KLF5, and the promoter activity of KLF5 was markedly suppressed by KLF8 ectopic expression. Finally, the overexpression of KLF5 suppressed the promoter activity of SMA and $SM22{\alpha}$, thereby reduced the contractility in response to the stimulation of angiotensin II. These results suggest that cross-regulation of KLF family of transcription factors plays an essential role in the VSMC phenotype.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1197-1204
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• 1997

Between April 1981 and June 1996, 65 patients had aortic root replacement at our institution. Disease entities were pure aortic annuloectasia in 31 patients(47.7%), Stanford type A aortic dissection with annuloectasia in 8(43.1%), atherosclerotic aneurysm with aortic regurgitation in 4(6.2%), and paravalvular leakage after aortic valve replacement in 2(3.1 %). 34 patients(52.3%) had the clinical stigmata of the Marfan syndrome. The operative procedures were Bentall operation in 61 patients(93.8%); 3 of conventional procedure and 58 of Cabrol's modification, aortic valve-sparing operation in 2(3.1 %), and root replacement with homograft in 2(3.1%). Hospital deaths occurred in 3 patients(4.8%) because of uncontrolled bleeding(1) and bypass weaning failure due to low cardiac output(2), and all had emergency operation with Cabrol's procedure. Postoperative complications developed in 19(29.2%) patients and most of them were transient. Surviving 62 patients have been followed up to cumulative total 315.0 patient-years(mean 60.2 $\pm$42.4 months). Late deaths occurred in 7 patients(11.3%), aneurysmal changes of remaining aorta were detected in 12 patients(19.4%). Actuarial survival rate at 10 years was 72.0 $\pm$ 9.7%, and the subsequent aortic operation-free rate at 10 years was 68.0$\pm$ 8.9% In a multivariate analysis, Marfan syndrome, emergency operation, preoperative dissection, combined arch replacement, and total circulatory arrest emerged as significant risk factors for hospital death or subsequent aortic operation. Over 60 years of age was the only risk factor for late death. Our 16 years'cummulative experience shows that aortic root replacement, mainly by means of Cabrol's procedure, can be applied successfully to variety of aortic root disease. However, long-term follow up will be needed to determine the late result of aortic valve-saving operation and root replacement with homograft. When dissection is present or the distal native aorta is diseased in'Marfan patients, close follow-up is necessary because of the subsequent aneurysmal change of remaining aorta.

• Clinical and Experimental Pediatrics
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• v.60 no.12
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• pp.390-394
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• 2017

Purpose: Atrioventricular nodal reentry tachycardia (AVNRT) is less common in pediatric patients than in adult patients. Thus, data for pediatric AVNRT patients are insufficient. Hence, we aimed to analyze the patient characteristics, treatment, and any recurrences in pediatric AVNRT patients. Methods: We reviewed the records of 50 pediatric AVNRT patients who had undergone radiofrequency catheter ablation (RFCA) between January 1998 and December 2016 at a single regional center. The patients were aged ${\leq}18years$. Results: Among 190 pediatric patients who underwent RFCA for tachyarrhythmia, 50 (26.3%; mean age, $13.4{\pm}2.6years$) were diagnosed as having AVNRT by electrophysiological study. Twenty-five patients (25 of 50, 50%) were male. Twenty patients (20 of 50, 40%) used beta-blockers before RFCA. All patients had no structural heart disease except 1 patient with valvular aortic stenosis and coarctation of the aorta. RFCA was performed using the anatomic approach under fluoroscopic guidance. The most common successfully ablated region was the midseptal region (25 of 50, 50%). Slow pathway (SP) ablation and SP modulation were performed in 43 and 6 patients, respectively. Complication occurred in 1 patient with complete atrioventricular block. During follow-up, 6 patients had recurrence of supraventricular tachycardia, as confirmed by electrocardiography. Among them, 5 underwent successful ablation at the first procedure. In 1 patient, induction failed during the first procedure. Conclusion: RFCA is safe and effective in pediatric AVNRT patients. However, further research is needed for establishing the endpoints of ablation in pediatric AVNRT patients and for identifying risk factors by evaluating data on AVNRT recurrence after RFCA.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.111-114
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• 2009

Aorto-iliac artery aneurysms are very rare and the natural course of this disease is not well known. However, the risk of rupture is high and the mortality rate after rupture is extremely high. Preserving the pelvic circulation is important for the treatment of aorto-iliac artery aneurysms. We report here on a case of a patient suffering with aorto-iliac artery aneurysms, and these were treated by a hybrid endovascular operation that combined an open bypass of both iliac vessels with endovascular repair.

• Journal of Chest Surgery
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• v.47 no.6
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• pp.529-532
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• 2014

An eight-day-old neonate was diagnosed with dextro-transposition of the great arteries, atrial septal defect, patent ductus arteriosus, and a single sinus origin of the coronary arteries. The single coronary artery originated from the left sinus (sinus 2), had a proximal left circumflex arterial branch, and passed anteriorly to the right side of the aorta, further branching into the right coronary and left anterior descending arteries. We successfully performed an arterial switch operation and coronary transfer by tube graft reconstruction with autologous aortic tissue to treat the dextro-transposition of the great arteries and atrial septal defect with a single-sinus origin of the coronary arteries.

• Journal of Chest Surgery
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• v.48 no.6
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• pp.415-418
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• 2015

Right aortic arch with isolation of the left subclavian artery is a rare anomaly. The incidence of bilateral ductus arteriosus is sporadic, and a right aortic arch with isolation of the left subclavian artery in association with bilateral ductus arteriosus is therefore extremely rare. Since the symptoms and signs of isolation of the left subclavian artery can include the absence or underdevelopment of the left arm, subclavian steal syndrome, or pulmonary artery steal syndrome, the proper therapeutic approach is controversial. We report a case in which surgical reconstruction was used to treat isolation of the left subclavian artery with right aortic arch in association with bilateral ductus arteriosus and a ventricular septal defect.

• Journal of Chest Surgery
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• v.26 no.2
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• pp.154-157
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• 1993

Aortic dissection of the young woman without Marfan disease is related, in most instances, to pregnancy. We experienced a case of acute type A aortic dissection. The patient was 25 years old woman in 35 weeks of gestational age without evidence of Marfan's syndrome. The challenge of management was successfully met by delivery of the fetus first, followed by aorta surgery. 42 minutes of total circulatory arrest and 104 minutes of total aortic cross clamp time were needed. 34 minutes of selective cerebral perfusion via right axillary artery was used. The patient had uneventful hospital course and was discharged with her healthy baby on 15 th postoperative day.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.84-87
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• 2016

Midaortic syndrome (MAS) is a rare vascular disease that commonly causes renovascular hypertension. The lumen of the abdominal aorta narrows and the ostia of the branches show stenosis. MAS is associated with diminished pulses in the lower extremities compared with the upper extremities, severe hypertension with higher blood pressure in the upper rather than lower extremities, and an abdominal bruit. The clinical symptoms are variable, and recognition in children with hypertension can aid early diagnosis and optimal treatment. Hypertension with MAS is malignant and often refractory to several antihypertensive drugs. Recently, radiologic modalities have been developed and have led to numerous interventional procedures. We describe the case of a 3-year-old boy presenting with left ventricular hypertrophy whose severely elevated blood pressure led to the diagnosis of idiopathic MAS. This case highlights the importance of measuring blood pressure and conducting a detailed physical examination to diagnose MAS. This is the first reported case of idiopathic MAS diagnosed in childhood in Korea.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.373-378
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• 1988

Since the introduction of percutaneous; transluminal coronary angioplasty[PTCA] by Grunt-zig in 1977, this is widely used in some patients with coronary artery disease and is an effective alternative to surgery for many patients. Indications for emergency coronary artery bypass graft[CABG] after PTCA are prolonged chest pain, worsening of coronary artery obstruction, "current of injury" by electrocardiogram, cardiogenic shock, and in a lesser incidence, ventricular fibrillation, coronary artery dissection[without obstruction], heart block, and intractable cardiac arrest. Recently, we have experienced one case of emergency CABG following unsuccessful PTCA. The patient was 54 year-old male and admitted with complaint of angina pectoris. The routine electrocardiogram revealed within normal limit. The treadmill test revealed severe chest pain after 2 min. exercise. Coronary cineangiogram revealed 95% segmental stenosis of the proximal right coronary artery. Our cardiologist was planned PTCA. During PTCA, severe chest pain and ischemic pattern on electrocardiogram were developed. But they were not relieved even by morphine and nitroglycerin till 90 min. So we performed emergency single coronary artery bypass graft from aorta to proximal right coronary artery with great saphenous vein. The patient had an excellent postoperative recovery and was free from anginal attack. He has shown striking improvement in general status[NYHA functional class 1] during 6 months after operation.operation.

• Journal of Chest Surgery
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• v.39 no.2 s.259
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• pp.157-161
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• 2006

Use of endovascular stent-graft in aortic aneurysm disease is now accepted as an alternative treatment to surgery. We successfully treated two patients with high risk of thoracic aortic aneurysm with percutaneous endovascular stent-graft. Three and ten months follow up chest CT showed obliteration of aneurysm and there was no complication after stent grafting.