Arterialization of human vein grafts is associated with tenascin-C expression.

OBJECTIVES: This study was performed to test the hypothesis that tenascin-C (TN-C), an extracellular matrix (ECM) protein with counteradhesive chemotactic and vascular growth-promoting effects, is expressed in "arterialized" human saphenous vein grafts (SVGs). BACKGROUND: Tenascin-C is expressed in the vessel wall after vascular injury in the experimental model, where it has been implicated in the formation of neointima. Overexpression of TN-C has also been implicated in the development and progression of pulmonary hypertension. Saphenous vein grafts are exposed to hemodynamic stress when interposed in the arterial circulation and mechanical stress upregulates expression of TN-C, whereas stress-relaxation suppresses its synthesis. We hypothesized that the hemodynamic stress of increased arterial pressure could also induce TN-C expression in SVG. METHODS: We examined the expression of TN-C protein and mRNA in normal vein and "arterialized" human SVG using immunohistochemistry and in situ hybridization, respectively. RESULTS: TN-C protein was not detected in control human saphenous veins; however, it was uniformly and strongly expressed in the adventitia and media of patent human vein grafts, with minimal or no expression in the neointima (n = 27, 100%). In situ hybridization showed that TN-C mRNA was not detected in the neointima, but was strongly upregulated in the adventitia and media, corroborating immunostaining data (n = 10, 100%). Unlike patent SVG, TN-C was not expressed in the adventitia of occluded grafts, except for a low level of expression around the newly formed vessels in neointima (n = 5, 100%). Smooth muscle cell-specific staining demonstrated that the lack of expression of TN-C in occluded vein grafts is not due to the lack of presence of smooth muscle cells in the graft. CONCLUSIONS: These findings suggest that placement of a venous graft in the arterial system leads to expression of TN-C, which may in turn facilitate graft remodeling. Conversely, loss of flow and intravascular pressure, associated with vein graft occlusion, is accompanied by disappearance of TN-C expression.     

Arterialization of the portal vein in cirrhosis: the findings at celiac arteriography

An angiographic study of a new operation for portal hypertension involving arterialization of the portal vein in combination with an end-to-side portacaval shunt is described. The angiographic appearances differ from those of end-to-side shunts alone. With the new operation there is, in particular, no significant change in the wedge pressure or in the hepatic artery size from preoperative to postoperative studies, and in the majority of patients, the liver size is also unchanged. The incidence of porto-systemic shunting from the portal vein to the low pressure caval system (66%) is lower than for end-to-side shunts alone. Changes are seen in the distal portal bed in the majority of cases.     

Bigeminal pulmonary vein ectopy suppressed by pulmonary vein isolation

A 58-year-old man with atrial fibrillation underwent pulmonary vein (PV) isolation (PVI). Bigeminal atrial premature beats persisted from the beginning of the PVI. The cardiac recordings from a basket catheter (BC) revealed the PV ectopic origin in the distal right superior PV. Successful PVI with the guidance of BC was confirmed by the appearance of concealed ectopy. Surprisingly, the PV ectopy completely disappeared immediately after the successful PVI. The findings suggest that the generation of PV trigger is sometimes dependent on left atrial input and that the underlying mechanism of the PV trigger may have been triggered activity or reentry.     

选择性上肺静脉造影显示下肺静脉开口位置的研究

目的探讨心房颤动(简称房颤)射频消融治疗中通过选择性上肺静脉造影显示下肺静脉开口位置的可行性与效果。方法97例房颤患者,取左前斜位(LAO)50°和右前斜位(RAO)50°两个体位进行左上肺静脉造影。取LAO50°及RAO30°两个体位进行右上肺静脉造影。结果97例(100%)均可通过选择性左上肺静脉造影清晰显示左下肺静脉开口的下缘,其中78例(80.4%)可以清晰显示左下肺静脉的开口前缘。79例(81.4%)患者可以清晰显示左下肺静脉开口的后缘。选择性右上肺静脉造影时,86例(88.7%)能够清晰识别右下肺静脉开口下缘,76例(78.4%)能清晰显示右下肺静脉开口前缘,81例(83.5%)能清晰显示右下肺静脉开口后缘。结论选择性上肺静脉造影不仅能够显示上肺静脉的开口位置,而且在大部分患者中亦能较清晰显示下肺静脉的开口解剖。     

射频导管消融肺静脉或肺静脉前庭治疗心房颤动的并发症

总结射频导管消融电隔离肺静脉和上腔静脉(合称为大静脉)治疗心房颤动(房颤)的并发症。     

Spontaneous and induced pulmonary vein tachycardia after pulmonary vein isolation.

A case is reported of recurrence of paroxysmal atrial fibrillation after pulmonary vein ablation. A second procedure achieved isolation of three pulmonary veins and showed persistence of pulmonary vein tachycardia in one with implications concerning the electrophysiology of atrial fibrillation.     

Congenital pulmonary vein stenosis

Congenital pulmonary vein stenosis is a rare and serious form of congenital heart disease. Between 1969 and 1982 10 patients with this lesion were studied. In 2 patients the condition was diagnosed at autopsy; these patients died before the presence of congenital heart disease was suspected. Of the 8 in whom the condition was diagnosed during life, it was suspected clinically in 6 and found unexpectedly at cardiac catheterization in 2. All underwent operation, and 5 were hospital survivors. In all survivors rapid and progressive restenosis of the pulmonary veins occurred over the next several months. Three of the 5 underwent reoperation, but progressive restenosis recurred and all eventually died of this condition. Thus, despite partial surgical relief of pulmonary vein stenosis, the lesion is apparently one of relentless progression. No surgical repair has been successful in the cure or long-term palliation of this lethal lesion.     

Primary pulmonary vein stenosis

Primary pulmonary vein stenosis (PVS) is a rare entity with a high mortality rate. Relatively little is known regarding predictors of outcome or the appropriate timing of intervention. The Pediatric Cardiac Care Consortium database (n = 98,126) was searched for patients who had undergone cardiac catheterization or surgical procedures with primary diagnoses of PVS or atresia from 1982 to 2002. Patients with total or partial anomalous pulmonary venous return, cor triatriatum, previous atrial switch, or previous lung transplantation were excluded. Additional data were obtained through questionnaires sent to each Pediatric Cardiac Care Consortium institution. A total of 31 patients were identified with primary PVS. Excluding lung transplantation, 16 of 31 patients underwent intervention to relieve PVS. Univariate predictors of lung death, defined as death or lung transplantation, included younger age at diagnosis (16.2 vs 52.5 months, p = 0.0221), higher initial mean pulmonary arterial pressure (46.4 vs 26.8 mm Hg, p = 0.0003), and bilateral vessel involvement (lung death in 17 of 19 vs 0 of 9 patients, p <0.0001). Patients diagnosed at 18 months of age and those with initial mean pulmonary arterial pressures >33 mm Hg had incidences of lung death of 76% and 88%, respectively. In conclusion, primary PVS carries a high mortality rate despite attempts at palliation. Patients diagnosed at 18 months of age, having initial mean pulmonary arterial pressures >33 mm Hg, or with bilateral vessel involvement are at significantly increased risk for death or lung transplantation. In these high-risk groups, death occurs rapidly despite intervention, and lung transplantation should be an early consideration.     

Unilateral pulmonary vein stenosis

Unilateral pulmonary vein stenosis is a rare congenital anomaly. A case is described in a girl who first presented at the age of four years with recurring haemoptysis but in whom diagnosis was not established until she was 16 years old. Pulmonary angiography demonstrated a minimally hypoplastic right pulmonary artery, and the laevophase showed normal pulmonary venous return from the left lung, but none from the right. Surgical treatment was necessary because of life threatening haemoptysis, and pneumonectomy was required in the light of the findings at operation.     

Isolated pulmonary vein atresia

Two patients with isolated atresia of the pulmonary veins are described. One patient presented with haemoptysis and the other with recurrent unilateral chest infections. The diagnosis was confirmed in both instances by cardiac catheterisation and pulmonary angiography. One patient died one year after the diagnosis was made and the second child has been stable during a follow up period of three years.     

肺静脉前庭重构与环肺静脉前庭电隔离术后肺静脉-左房电传导恢复的关系

目的分析肺静脉前庭重构与环肺静脉前庭电隔离术(CPVI)后肺静脉-左房电传导恢复之间的关系。方法入选2007年1月至2009年9月因房颤行导管射频消融术后复发,再次消融患者359例(阵发性房颤180例,持续性房颤179例)。LASSO环状电极标测肺静脉-左房电传导恢复情况,在Carto系统引导下行补点消融。利用CARTO系统自带软件测量左右肺静脉前庭面积。结果 359例患者均顺利完成导管射频消融。阵发性房颤患者中有144例(80%)电传导恢复,其中单支肺静脉电传导恢复占45例(31.25%),2支占58例(40.28%),3支占24例(16.67%),4支恢复占17例(11.81%)。持续性房颤患者中有155例(86.59%)电传导恢复,其中单支肺静脉电传导恢复占24例(15.48%),2支占72例(46.45%),3支占17例(10.97%),4支占42例(27.1%)。阵发性房颤左肺静脉前庭面积(6.15±0.65)cm2,右肺静脉前庭面积(7.95±2.24)cm2。持续性房颤左肺静脉前庭面积(10.48±1.00)cm2,右肺静脉前庭面积(11.4±2.16)cm2。统计学分析提示阵发性房颤CPVI术后单支肺静脉电传导恢复比例高于持续性房颤(P=0.001),而持续性房颤4支肺静脉电传导恢复比例高于阵发性房颤(P=0.001)。阵发性房颤左、右肺静脉前庭面积均小于持续性房颤(P0.001,P=0.022)。结论持续性房颤肺静脉前庭重构程度高于阵发性房颤,因此持续性房颤电隔离术后肺静脉-左房电传导恢复比例高于阵发性房颤。     

Comparison of stent versus balloon angioplasty for pulmonary vein stenosis complicating pulmonary vein isolation

Introduction: Pulmonary vein stenosis (PVS) is a rare but significant complication of pulmonary vein isolation (PVI). Dilation and stent angioplasty have been described but not compared.
Methods and Results: All percutaneous interventions for PVS complicating PVI between December 2000 and March 2007 were reviewed. Acute success, defined as post-intervention stenosis ≤30%, and long-term outcome of dilation versus stent angioplasty were compared. Freedom from restenosis was defined as freedom from repeat intervention. Overall outcome for all interventions was examined. We studied 34 patients with 55 stenotic veins followed for a mean of 25 months. Dilation was performed in 39 veins and stenting in 40 veins (16 primarily, 24 after dilation restenosis). Acute success and restenosis rates were 42% and 72% for dilation versus 95% (P < 0.001) and 33% for stenting. Time to restenosis was greater for stent angioplasty (P = 0.003). Stents ≥10 mm in diameter had lower restenosis than smaller stents. Risk factors for restenosis included small reference vessel diameter and longer time from PVI to intervention for PVS. All but two patients experienced improvement (n = 10) or resolution of symptoms (n = 22). The mean percent stenosis decreased from 82% to 21% for the entire cohort and mean flow to the lung quadrant increased from 10% to 17%.
Conclusion: Stent angioplasty results in less restenosis than dilation, particularly for stents ≥10 mm. Early referral may improve long-term patency by minimizing reference vessel atrophy. Most patients with PVS post-PVI can be improved symptomatically with catheter intervention.     

Percutaneous pulmonary vein stenting for the treatment of severe stenosis after pulmonary vein isolation

INTRODUCTION: Pulmonary vein stenosis (PVS) is a potential complication of pulmonary vein isolation (PVI) using radiofrequency energy. The aim of our study was the evaluation of the severity and long-term outcome of primary angioplasty and angioplasty with pulmonary vein stenting for PVS. METHODS AND RESULTS: Twelve patients with 15 PVS (greater than 70% stenosis) were prospectively evaluated. Primary dilation of the stenosis was performed because of clinical symptoms (10 patients) and/or the lung perfusion scans showed a significant perfusion defect (11 patients). Magnetic resonance imaging and lung perfusion scans performed before, directly after, during 3-month, and 6-month follow-up. In the stenting group additional multislice CT-scans directly after, during 6-month, and 12-month follow-up were performed. Within 2 months after primary balloon angioplasty, the PV size parameters were significantly reduced (P < 0.001) with recurrence of PVS in 11 of 15 PVs (73%). Pulmonary vein stenting in 8 patients and 11 PVs resulted in no vein stenosis during 12-month follow-up. Normalization of lung perfusion was noted in 8 of 12 patients. We observed 2 patients with hemoptysis during PV dilation, as severe complications with potential life-threatening character. CONCLUSION: PVS stenting seems to be superior to balloon angioplasty and effective at least over a period of 12 months in treating acquired PVS after pulmonary vein isolation.     

Different strategies for performing pulmonary vein isolation in patients with pulmonary vein rhythm

Pulmonary vein (PV) isolation was performed in atrial fibrillation (AF) patients whose cardiac rhythm was dominated by the ectopic beats originating from the PV. We herein report two cases with dominant PV ectopic rhythm that underwent catheter ablation for the treatment of paroxysmal AF. In one case, a permanent pacemaker implantation was required to treat a symptomatic long sinus pause after the isolation of all four PVs, while no AF was documented during the 5-year period after ablation. However, the isolation of all four PVs except for a PV with a dominant ectopic rhythm was performed in the other case. The latter case was free from both AF and symptomatic bradycardia following the procedure without the implantation of a pacemaker. Selective PV isolation therefore appears to be an effective therapy to both achieve the successful treatment of AF and to prevent the manifestation of sick sinus syndrome.