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Outflow Tract (outflow + tract)
Kinds of Outflow Tract Terms modified by Outflow Tract Selected AbstractsSurgery for Ruptured Sinus of Valsalva Aneurysm into Right Ventricular Outflow Tract: Role of Intraoperative 2D and Real Time 3D Transesophageal EchocardiographyECHOCARDIOGRAPHY, Issue 7 2010Shrinivas Gadhinglajkar M.D. A major limitation of the 2D echocardiography during surgery for a complex cardiac lesion is its inability to provide an accurate spatial orientation of the structure. The real time 3D transesophageal echocardiography (RT-3D-TEE) technology available in Philips IE 33 ultrasound machine is relatively new to an operation suite. We evaluated its intraoperative utility in a patient, who was operated for repair of a ruptured sinus of Valsalva aneurysm (RSOVA) and closure of a supracristal ventricular septal defect. The VSD and RSOVA were visualized through different virtual windows in a more promising way on intraoperative RT-3D-TEE than on the 2D echocardiography. The acquired images could be virtually cropped and displayed in anatomical views to the operating surgeon for a clear orientation to the anatomy of the lesion. RT-3D-TEE is a potential intraoperative monitoring tool in surgeries for complex cardiac lesions. (Echocardiography 2010;27:E65-E69) [source] The Rupture of Periaortic Infective Aneurysm into the Left Atrium and the Left Ventricular Outflow Tract: Preoperative Diagnosis by Transthoracic EchocardiographyECHOCARDIOGRAPHY, Issue 3 2002Ewa Lastowiecka M.D. We present a rare complication of infective endocarditis, perforated periaortic abscess with fistulous communication between the aortic root, the left atrium, and the left ventricular outflow tract. Preoperative transthoracic echocardiographic diagnosis was confirmed intraoperatively. The patient was treated successfully by aortic homograft implantation. [source] Current Strategy of Repair of Tetralogy of Fallot in Children and Adults: Emphasis on a New Technique to Create a Monocusp-Patch for Reconstruction of the Right Ventricular Outflow TractJOURNAL OF CARDIAC SURGERY, Issue 6 2008D.Sc., Guo-Wei He M.D., Ph.D. Methods: From 2001 through 2005, 74 patients (50 male, 24 female; mean age of 13.6 ± 0.8 years, ranging from four to 34 years) with TOF (67) or double outlet RV (DORV)-type-TOF (seven) underwent complete repair. The resection of RVOT stenosis ± pulmonary valvotomy was principally through RA. A new two-patch technique to create a folded mono-cusp valve by using autologous pericardium was applied since August 2004. Results: The repair was through RA in 52 patients and through RA + RVOT/PA in 22 patients (18/4). TAPR was performed in 17 patients (23%, eight non-valved and nine valved). The aortic cross-clamp time was 130.1 ± 6.8 min in TAPR group and 85.8 ± 4.6 min in non-TAPR group (p < 0.0001). The operative mortality was 4.0% (3/74) in all and 2.9% (2/67) in TOF patients (due to low output, uncontrollable bleeding, and repeated bleeding from the pulmonary collateral vessels late) and was similar in TAPR or non-TAPR. The valved patch-repaired patients had mild PI and good RV function postoperatively up to eight to 12 months. Conclusions: Repair of TOF in older children/adults should include low rate of TAPR of RVOT. If indicated, the new folded monocusp-patch technique is recommended. It is an effective and simple way to markedly reduce postoperative PI with no additional cost. [source] A Case Report of Surgical Septal Myectomy of Hypertrophic Cardiomyopathy With Concomitant Left Ventricular Outflow Tract and Mid-Ventricular ObstructionsJOURNAL OF CARDIAC SURGERY, Issue 6 2006Dr W. Williams No abstract is available for this article. [source] Clinical Usefulness of a Multielectrode Basket Catheter for Idiopathic Ventricular Tachycardia Originating from Right Ventricular Outflow TractJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2001TAKESHI AIBA M.D. Basket Catheter in Idiopathic VT.Introduction: It often is difficult to determine the optimal ablation site for idiopathic ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT) when the VT or premature ventricular complex (PVC) does not occur frequently. The aim of our study was to evaluate the usefulness of a multielectrode basket catheter for ablation of idiopathic VT originating from the RVOT. Methods and Results: Radiofrequency (RF) catheter ablation was performed using a 4-mm tip, quadripolar catheter in 50 consecutive patients with 81 VTs originating from the RVOT with (basket group = 25 patients with 45 VTs) or without (control group = 25 patients with 36 VTs) predeployment of a multielectrode basket catheter composed of 64 electrodes. Deployment of the multielectrode basket catheter was possible and safe in all 25 patients in the basket group. Ablation was successful in 25 (100%) of 25 patients in the basket group and in 22 (88%) of 25 patients in the control group. The total number of RF applications and the number of RF applications per PVC morphology did not differ between the two groups. However, both the fluoroscopic and ablation procedure times per PVC morphology were shorter in the basket group than in the control group (36.8 ± 14.1 min vs 52.0 ± 32.5 min, P = 0.04; 60.0 ± 14.6 vs 81.5 ± 51.2 min, P = 0.05). This difference was more pronounced in the 29 patients in whom VT or PVC was not frequently observed. Conclusion: The multielectrode basket catheter is safe and useful for determining the optimal ablation site in patients with idiopathic VT originating from the RVOT, especially in those without frequent VT or PVC. [source] Early Results of Balloon Dilatation of the Stenotic Bovine Jugular Vein Graft in the Right Ventricular Outflow Tract in ChildrenJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2008J. STEINBERG M.D. The aim of this study was to evaluate the early results of interventional balloon dilatation of stenotic bovine jugular vein (BJV) grafts implanted for reconstruction of the right ventricular outflow tract (RVOT) in children. Methods: From May 2001 to December 2005, 153 BJV grafts were implanted in children in our institution. An average of 16.9 (7.6,41.1) months after implantation, 17 balloon dilatations in a significant stenosis proximal (n = 1), distal anastomosis (n = 8), BJV valve (n = 3), or at multiple sites (n = 5) were performed in 15 children (male:female = 9:6) with a mean age of 3.9 (0.8,13.0) years. Balloon diameter was 75,133.3% (mean 100.3) of the original BJV size. Mean follow-up was 8.8 (2 days to 22.8 months) months. Results: In 10 interventions (58.8%) the instantaneous peak gradient was reduced below 50 mmHg. A balloon diameter ,100% of the original BJV size correlated significantly with a successful intervention. No major complications, two minor (nonobstructive floating membranes at the dilatation site and one septicemia) occurred afterward. Freedom from reintervention after 6 months was 58.2% for all, 77.8% for dilatations of the proximal anastomosis and mixed stenotic lesions, and 33.3% for the distal anastomosis. Conclusion: Balloon dilatation of stenotic BJV grafts is safe and can significantly reduce the pressure gradient in two-thirds of interventions. Balloon diameters above the original graft size should be aimed for. The most frequent stenosis of the distal anastomosis tends to renarrow early after dilatation. Nevertheless, balloon dilatation should be considered in nearly every stenotic graft to gain time until a surgical or interventional graft exchange. [source] Problems in the Canine Left Ventricular Outflow TractJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2001DACVIM, John D. Bonagura DVM No abstract is available for this article. [source] Right Ventricular Septal Pacing: A Comparative Study of Outflow Tract and Mid Ventricular SitesPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2010RAPHAEL ROSSO M.D. Background: Prolonged right ventricle (RV) apical pacing is associated with left ventricle (LV) dysfunction due to dysynchronous ventricular activation and contraction. Alternative RV pacing sites with a narrower QRS compared to RV pacing might reflect a more physiological and synchronous LV activation. The purpose of this study was to compare the QRS morphology, duration, and suitability of RV outflow tract (RVOT) septal and mid-RV septal pacing. Methods: Seventeen consecutive patients with indication for dual-chamber pacing were enrolled in the study. Two standard 58-cm active fixation leads were passed to the RV and positioned in the RVOT septum and mid-RV septum using a commercially available septal stylet (model 4140, St. Jude Medical, St. Paul, MN, USA). QRS duration, morphology, and pacing parameters were compared at the two sites. The RV lead with less-satisfactory electrical parameters was withdrawn and deployed in the right atrium. Results: Successful positioning of the pacing leads at the RVOT septum and mid-RV septum was achieved in 15 patients (88.2%). There were no significant differences in the mean stimulation threshold, R-wave sensing, and lead impedance between the two sites. The QRS duration in the RVOT septum was 151 ± 14 ms and in the mid-RV septum 145 ± 13 ms (P = 0.150). Conclusions: This prospective observational study shows that septal pacing can be reliably achieved both in the RVOT and mid-RV with active fixation leads using a specifically shaped stylet. There are no preferences in regard to acute lead performance or paced QRS duration with either position. (PACE 2010; 33:1169,1173) [source] Compression of the Left Ventricular Outflow Tract During Cardiopulmonary ResuscitationACADEMIC EMERGENCY MEDICINE, Issue 10 2009Sung Oh Hwang MD Abstract Objectives:, This prospective observational study was performed to investigate if the hand position used for external chest compressions is in an optimal position for compressing the ventricles during standard cardiopulmonary resuscitation (CPR). Methods:, Transesophageal echocardiography (TEE) was performed during standard CPR in 34 patients with nontraumatic cardiac arrest (24 males, mean ± standard deviation [SD] age = 56 ± 12 years). On the recorded image of TEE, an area of maximal compression (AMC) was identified, and the degree of compression at the AMC and the left ventricular stroke volume was calculated. Results:, A significant narrowing of the left ventricular outflow tract (LVOT) or the aorta was noted in all patients, with the degree of compression at the AMC ranging from 19% to 83% (mean ± SD = 49 ± 19%). The AMC was found at the aorta in 20 patients (59%) and at the LVOT in 14 patients (41%). A significant narrowing of more than 50% of the diameter at the end of the relaxation phase occurred in 15 patients (44%). On linear regression, the left ventricular stroke volume was correlated with the location of the AMC (R2 = 0.165, p = 0.017). Conclusions:, The outflow of the left ventricle is affected during standard CPR, resulting in varying degrees of narrowing in the LVOT and/or the aortic root. [source] Frequent Premature Ventricular Complexes Originating from the Right Ventricular Outflow Tract Are Associated with Left Ventricular DysfunctionANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 1 2008Yumiko Kanei M.D. Background: Recent case series have shown reversal of left ventricular (LV) dysfunction after catheter ablation of frequent premature ventricular complexes (PVCs) originating from the right ventricular outflow tract (RVOT). We conducted a retrospective study to evaluate the prevalence of patients with frequent RVOT PVCs (,10 per hour) and LV dysfunction. Methods: RVOT PVC was defined as PVC with left bundle branch block morphology and inferior axis on a 12-lead ECG. We included patients with frequent RVOT PVCs on 24-hours Holter monitor who had a recent evaluation of LV function. Patients with structural heart disease, including obstructive coronary artery disease, were excluded. Patients were divided into three groups based on the number of PVCs (<1000/24 hour, 1000,10,000/24 hour, ,10,000/24 hour), and the prevalence of LV dysfunction was evaluated in each group. Results: Our analysis included 108 patients: 24 patients had <1000PVCs/24 hour, 55 patients had 1000,10,000PVCs/24 hour, and 29 patients had ,10,000PVCs/24 hour. The prevalence of LV dysfunction was 4%, 12%, and 34%, respectively (P = 0.02). With logistic regression analysis, non-sustained ventricular tachycardia was an independent predictor of LV dysfunction with odds ratio of 3.6 (1.3,10.1). Conclusion: We demonstrated a significant association between frequent RVOT PVCs and LV dysfunction in patients without structural heart disease. [source] Reconstruction of Right Ventricular Outflow Tract with Stentless Xenografts in Ross ProcedureARTIFICIAL ORGANS, Issue 12 2002Takuro Tsukube Abstract: To investigate whether the use of a stentless porcine aortic xenograft can be an alternative for right ventricular outflow tract (RVOT) reconstruction during the Ross procedure, 9 patients underwent the Ross procedure and RVOT reconstruction with a stentless xenograft since January 2000. After the aortic valve was replaced with a pulmonary autograft, a stentless xenograft with a xeno- pericardial roll was implanted in the RVOT. One patient required subsequent aortic valve replacement because of severe regurgitation of the pulmonary autograft. All patients recovered well from the operation. The right ventricle-pulmonary arterial pressure gradient was 18 ± 7 mm Hg at discharge and was not significantly increased during the 2-year follow-up period. Although 1 patient died of ventricular arrhythmia 5 months after, his cardiac function was normal, and transpulmonary valve pressure was 19 mm Hg in the follow-up. The other 7 patients are currently in New York Heart Association functional Class I. Although long-term follow-up is required to explain the durability, the stentless xenograft with a pericardial roll is considered to be an alternative for reconstruction of the RVOT within 2 years after the Ross procedure. [source] Second lineage of heart forming region provides new understanding of conotruncal heart defectsCONGENITAL ANOMALIES, Issue 1 2010Yuji Nakajima ABSTRACT Abnormal heart development causes various congenital heart defects. Recent cardiovascular biology studies have elucidated the morphological mechanisms involved in normal and abnormal heart development. The primitive heart tube originates from the lateral-most part of the heart forming mesoderm and mainly gives rise to the left ventricle. Then, during the cardiac looping, the outflow tract is elongated by the addition of cardiogenic cells from the both pharyngeal and splanchnic mesoderm (corresponding to anterior and secondary heart field, respectively), which originate from the mediocaudal region of the heart forming mesoderm and are later located anteriorly (rostrally) to the dorsal region of the heart tube. Therefore, the heart progenitors that contribute to the outflow tract region are distinct from those that form the left ventricle. The knowledge that there are two different lineages of heart progenitors in the four-chambered heart provides new understanding of the morphological and molecular etiology of conotruncal heart defects. [source] Understanding heart development and congenital heart defects through developmental biology: A segmental approachCONGENITAL ANOMALIES, Issue 4 2005Masahide Sakabe ABSTRACT The heart is the first organ to form and function during development. In the pregastrula chick embryo, cells contributing to the heart are found in the postero-lateral epiblast. During the pregastrula stages, interaction between the posterior epiblast and hypoblast is required for the anterior lateral plate mesoderm (ALM) to form, from which the heart will later develop. This tissue interaction is replaced by an Activin-like signal in culture. During gastrulation, the ALM is committed to the heart lineage by endoderm-secreted BMP and subsequently differentiates into cardiomyocyte. The right and left precardiac mesoderms migrate toward the ventral midline to form the beating primitive heart tube. Then, the heart tube generates a right-side bend, and the d-loop and presumptive heart segments begin to appear segmentally: outflow tract (OT), right ventricle, left ventricle, atrioventricular (AV) canal, atrium and sinus venosus. T-box transcription factors are involved in the formation of the heart segments: Tbx5 identifies the left ventricle and Tbx20 the right ventricle. After the formation of the heart segments, endothelial cells in the OT and AV regions transform into mesenchyme and generate valvuloseptal endocardial cushion tissue. This phenomenon is called endocardial EMT (epithelial-mesenchymal transformation) and is regulated mainly by BMP and TGF,. Finally, heart septa that have developed in the OT, ventricle, AV canal and atrium come into alignment and fuse, resulting in the completion of the four-chambered heart. Altered development seen in the cardiogenetic process is involved in the pathogenesis of congenital heart defects. Therefore, understanding the molecular nature regulating the ,nodal point' during heart development is important in order to understand the etiology of congenital heart defects, as well as normal heart development. [source] Teratogenic effect of bis-diamine on embryonic rat heartCONGENITAL ANOMALIES, Issue 3 2000Masao Nakagawa ABSTRACT, Bis-diamine induces conotruncal anomalies including persistent truncus arteriosus, tetralogy of Fallot, interruption of the aortic arch, and ventricular septal defect in rat embryos when administered to the mother. Bis-diamine also induces extracardiac malformations including thymic hypoplasia, facial dysmorphism, forelimb anomalies and diaphragmatic hernia. However, the teratogenic mechanisms of this chemical in early developing rat hearts have not been fully established. Chimeric studies in chick and quail embryos demonstrated that the cranial neural crest cells reached the cardiac outflow tract, contributing to aorticopulmonary and truncal septation. Since an ablation of the cranial neural crest also produced the conotruncal anomalies, bis-diamine is proposed to disturb the normal migration of cardiac neural crest cells to the heart. Based on our data concerning cardiac anomalies induced by bis-diamine, we reviewed how the cardiac malformations were morphologically established in early developing rat hearts. Our data showed that 1) cardiovascular anomalies induced by bis-diamine are time- and species or strain- dependent. 2) bis-diamine reduces the number of neural crest cells migrating to participate in the conotruncal septation, 3) bis-diamine induces anomalous coronary arteries, thin ventricular walls and epicardial defects, and 4) some embryos cultured in the medium containing bis-diamine had extra-cardiac abnormalities including abnormal location of the otic placodes and delay in mid brain closure. Conclusively, bis-diamine does not appear to merely affect the cardiac development, but rather disturbs normal development of all the organs contributed to by neural crest cells. [source] Early and Midterm Results of an Alternative Procedure to Homografts in Primary Repair of Truncus Arteriosus CommunisCONGENITAL HEART DISEASE, Issue 3 2010Pedro Curi-Curi MD ABSTRACT Background., Repair of truncus arteriosus communis (TAC) in the neonatal and early infant period has become a standard practice. We report our experience on primary repair of TAC with a bovine pericardial-valved woven Dacron conduit as an alternative procedure to homografts, with a focus on early and midterm results. Methods., From January 2001 to December 2007, 15 patients with mean age 1.5 years (range 3 months to 8 years), underwent primary repair of simple TAC. Cases with cardiogenic shock, complex-associated cardiac lesions, or adverse anatomy of the truncal valve were excluded. The Collett and Edwards anatomical type classification of TAC was as follows: type I, 13 (87%); and type II, 2 (13%). Right ventricular outflow tract was reconstructed in all the cases with a bovine pericardial-valved woven Dacron conduit. Results., Overall mortality was 6.6% (1 death due to severe pulmonary hypertension). At a mean follow-up of 31 months (range 6,51), there were no deaths (5-year actuarial survival 93.4%). Out of the 14 midterm survivors, three developed stenosis of the pericardial-valved woven Dacron conduit, but only one underwent interventional procedure including percutaneous balloon dilation with stenting for associated left pulmonary artery hypoplasia. The rate of patients with no surgical or percutaneous reinterventions performed because of obstruction of the right ventricular outflow tract reconstruction in the midterm (5 years) was 86%. Conclusions., Truncus arteriosus communis repair with a bovine pericardial-valved woven Dacron conduit can be performed with a very low perioperative mortality and satisfactory midterm morbidity, favorably compared with that reported for the use of homografts. Interventional cardiac catheterization may delay the time of reoperation for inevitable conduit replacement due to stenosis. [source] Jarid2 is among a set of genes differentially regulated by Nkx2.5 during outflow tract morphogenesisDEVELOPMENTAL DYNAMICS, Issue 7 2010Jeremy L. Barth Abstract Nkx2.5, a transcription factor implicated in human congenital heart disease, is required for regulation of second heart field (SHF) progenitors contributing to outflow tract (OFT). Here, we define a set of genes (Lrrn1, Elovl2, Safb, Slc39a6, Khdrbs1, Hoxb4, Fez1, Ccdc117, Jarid2, Nrcam, and Enpp3) expressed in SHF containing pharyngeal arch tissue whose regulation is dependent on Nkx2.5. Further investigation shows that Jarid2, which has been implicated in OFT morphogenesis, is a direct target of Nkx2.5 regulation. Jarid2 expression was up-regulated in SHF mesoderm of Nkx2.5-deficient embryos. Chromatin immunoprecipitation analysis showed Nkx2.5 interaction with consensus binding sites in the Jarid2 promoter in pharyngeal arch cells. Finally, Jarid2 promoter activity and mRNA expression levels were down-regulated by Nkx2.5 overexpression. Given the role of Jarid2 as a regulator of early cardiac proliferation, these findings highlight Jarid2 as one of several potential mediators of the critical role played by Nkx2.5 during OFT morphogenesis. Developmental Dynamics 239:2024,2033, 2010. © 2010 Wiley-Liss, Inc. [source] Characterization of molecular markers to assess cardiac cushions formation in XenopusDEVELOPMENTAL DYNAMICS, Issue 12 2009Young-Hoon Lee Abstract The valves and septa of the mature heart are derived from the cardiac cushions, which develop from discrete swellings in two regions of developing heart tube: the atrioventricular (AV) canal and the ventricular outflow tract (OFT). In higher vertebrates, three distinct lineages contribute to the heart valves and septa, the endocardium, the myocardium, and the cardiac neural crest that will populate the cardiac jelly of the OFT. Very little is known about cardiac cushions development in amphibians. Here, we describe the expression of eight genes during key stages of cardiac cushion development in Xenopus. Among these genes, the Wnt antagonist Frzb1 and the transcription factors Xl-Fli, Sox8, Sox9, and Sox10 are differentially expressed in the mesenchyme of the OFT and AV cushions. These genes can be used in combination with lineage-tracing experiments to determine the embryonic origin of the cardiac cushions mesenchyme in Xenopus. Developmental Dynamics 238:3257,3265, 2009. © 2009 Wiley-Liss, Inc. [source] Role of VEGF and tissue hypoxia in patterning of neural and vascular cells recruited to the embryonic heartDEVELOPMENTAL DYNAMICS, Issue 11 2009Hongbin Liu Abstract We hypothesized that oxygen gradients and hypoxia-responsive signaling may play a role in the patterning of neural or vascular cells recruited to the developing heart. Endothelial progenitor and neural cells are recruited to and form branched structures adjacent to the relatively hypoxic outflow tract (OFT) myocardium from stages 27,32 (ED6.5,7.5) of chick development. As determined by whole mount confocal microscopy, the neural and vascular structures were not anatomically associated. Adenoviral delivery of a VEGF trap dramatically affected the remodeling of the vascular plexus into a coronary tree while neuronal branching was normal. Both neuronal and vascular branching was diminished in the hearts of embryos incubated under hyperoxic conditions. Quantitative analysis of the vascular defects using our recently developed VESGEN program demonstrated reduced small vessel branching and increased vessel diameters. We propose that vascular and neural patterning in the developing heart share dependence on tissue oxygen gradients but are not interdependent. Developmental Dynamics 238:2760,2769, 2009. © 2009 Wiley-Liss, Inc. [source] The lim domain only protein 7 is important in zebrafish heart developmentDEVELOPMENTAL DYNAMICS, Issue 12 2008Elisabeth B. Ott Abstract The LIM domain only protein 7 (LMO7), a member of the PDZ and LIM domain-containing protein family is a candidate gene with possible roles in embryonic development and breast cancer progression. LMO7 has been linked to actin cytoskeleton organization through nectin/afadin and to cell,cell adhesion by means of E-cadherin/catenin. In addition, LMO7 has been shown to regulate transcription of the nuclear membrane protein Emerin and other muscle relevant genes. In this study, we used in situ hybridization to investigate LMO7 expression during embryonic development in three widely used vertebrate model species: the zebrafish, the chicken and the mouse. Our temporal and spatial gene expression analysis revealed both common and distinct patterns between these species. In mouse and chicken embryos we found expression in the outflow tract, the inflow tract, the pro-epicardial organ and the second heart field, structures highly important in the developing heart. Furthermore, gene knockdown experiments in zebrafish embryos resulted in severe defects in heart development with effects on the conduction system and on heart localization. In summary, we present here the first developmental study of LMO7. We reveal the temporal and spatial expression patterns of this important gene during mouse, chicken and fish development and our findings suggest essential functions for LMO7 during vertebrate heart development. Developmental Dynamics 237:3940,3952, 2008. © 2008 Wiley-Liss, Inc. [source] The developing embryonic cardiac outflow tract is highly sensitive to oxidant stressDEVELOPMENTAL DYNAMICS, Issue 12 2007Steven A. Fisher Abstract This study tested the hypothesis that the remodeling of the cardiac outflow tract (OFT) may represent a developmental window of vulnerability to reactive oxygen species (ROS). Chick embryos were exposed in ovo or ex ovo to increasing concentrations of the stable oxidant hydrogen peroxide (H2O2). As assessed by trypan blue staining, H2O2 induced cell injury in the stage 25,30 OFT at concentrations as low as 1 nM. Higher concentrations were required to induce cell injury in the ventricular and atrial myocardium. Using DCFDA as an indicator of oxidant stress, H2O2 also induced a greater fluorescent signal in the OFT myocardium. H2O2 at these low concentrations also induced Caspase activity, indicative of activation of the pathway of PCD. Interestingly, the induction of Caspase-3 activity was predominately in the OFT cushion mesenchymal cells. Thus, the developing OFT is particularly sensitive to ROS-mediated injury, suggesting that ROS could play a role in the development of congenital defects of the cardiac OFT. Developmental Dynamics 236:3496,3502, 2007. © 2007 Wiley-Liss, Inc. [source] Differential levels of tissue hypoxia in the developing chicken heartDEVELOPMENTAL DYNAMICS, Issue 1 2006Jamie Wikenheiser Abstract Tissue hypoxia plays a critical role in normal development, including cardiogenesis. Previously, we showed that oxygen concentration, as assessed by the hypoxia indicator EF5, is lowest in the outflow tract (OFT) myocardium of the developing chicken heart and may be regulating events in OFT morphogenesis. In this study, we identified additional areas of the embryonic chicken heart that were intensely positive for EF5 within the myocardium in discrete regions of the atrial wall and the interventricular septum (IVS). The region of the IVS that is EF5-positive includes a portion of the developing central conduction system identified by HNK-1 co-immunostaining. The EF5 positive tissues were also specifically positive for nuclear-localized hypoxia inducible factor 1, (HIF-1,), the oxygen-sensitive component of the hypoxia inducible factor 1 (HIF-1) heterodimer. The pattern of the most intensely EF5-stained myocardial regions of the atria and IVS resemble the pattern of the major coronary vessels that form in later stages within or immediately adjacent to these particular regions. These vessels include the sinoatrial nodal artery that is a branch of the right coronary artery within the atrial wall and the anterior/posterior interventricular vessels of the IVS. These findings indicate that a portion of the developing central conduction system and the patterning of coronary vessels may be subject to a level of regulation that is dependent on differential oxygen concentration within cardiac tissues and subsequent HIF-1 regulation of gene expression. Developmental Dynamics 235:115,123, 2006. © 2005 Wiley-Liss, Inc. [source] Severe Right Ventricular Outflow Obstruction by Right Sinus of Valsalva AneurysmECHOCARDIOGRAPHY, Issue 3 2010Anil Avci M.D. Aneurysms of the sinus of Valsalva are rarely diagnosed cardiac anomalies, occurring in 0.14%,0.96% of patients who have undergone open heart surgical procedures. The most common congenital anomalies accompanying sinus of Valsalva aneurysm (SVA) are ventricular septal defect, bicuspid aortic valve, atrial septal defect, and coarctation of aorta. We report a patient with an unruptured right SVA presenting with severe right ventricular outflow tract (RVOT) obstruction, and coexisting patent foramen ovale (PFO) with a right to left shunt. It could be assumed that the increase in right atrial pressure due to RVOT obstruction had led to a right to left shunt across the patent foramen ovale. (Echocardiography 2010;27:341-343) [source] Baseline Echocardiographic Predictors of Dynamic Intraventricular Obstruction of the Left Ventricle during Dobutamine Stress EchocardiogramECHOCARDIOGRAPHY, Issue 10 2009Edmundo Jose Nassri Câmara M.D., Ph.D. Background: Intraventricular obstruction (IVO) during dobutamine stress echocardiogram (DSE) may be associated with or reproduce symptoms. Predictors of IVO are not well established. Methods: 149 patients were studied at rest and during DSE. The normal range of the left ventricular outflow tract (LVOT) velocities was investigated in 68 healthy patients. Results: 19 patients (13%) developed IVO (peak LVOT velocity > 271 cm/sec). A significant linear correlation was observed between peak LVOT velocity during DSE and the following rest parameters: LV end-diastolic dimension (r =,0.20, P = 0.018), LV end-systolic dimension (r =, 0.27, P = 0.001), relative wall thickness (r = 0.23, P = 0.006), shortening fraction (r = 0.24, P = 0.004), LVOT diameter (r =, 0.20, P = 0.023) and LVOT velocity (r = 0.29, P < 0.0001). Only relative wall thickness (P = 0.012) and LVOT diameter (P = 0.027) were independent predictors of IVO. As a dichotomous variable, a relative wall thickness ,0.44 was the only independent predictor of IVO (OR 5.7, 95% CI 1.6,20, P = 0.006), with sensitivity, specificity, negative predictive value, and positive predictive value of 77%, 62%, 95%, and 21%, respectively, and global accuracy of 63% (area under the ROC curve = 0.7). IVO was significantly associated with general cardiovascular symptoms (P = 0.0006) and with chest pain (P = 0.008). Conclusions: Relative wall thickness and LVOT diameter were independent predictors of obstruction. As a dichotomous variable, a relative wall thickness , 0.44 was the only independent predictor of dynamic IVO. [source] Prosthetic Valve Dysfunction Presenting as Intermittent Acute Aortic RegurgitationECHOCARDIOGRAPHY, Issue 8 2008Dali Fan M.D., Ph.D. We describe the case of a 43 year old man with a history of aortic stenosis, for which he had undergone aortic valve replacement in 1991 with a 25-mm Medtronic Hall prosthesis. He presented with several acute episodes of dyspnea and flash pulmonary edema. Transthoracic and transesophageal echocardiography performed to evaluate prosthetic valve function revealed evidence of "intermittent" episodes of AI, documented on color M-mode flow mapping to have a variable duration of diastolic flow (early vs. pandiastolic) across the left ventricular outflow tract and the pulse wave Doppler in the descending thoracic aorta showed similar variability in the duration of diastolic flow reversal. [source] Transesophageal and Transpharyngeal Ultrasound Demonstration of Reversed Diastolic Flow in Aortic Arch Branches and Neck Vessels in Severe Aortic RegurgitationECHOCARDIOGRAPHY, Issue 4 2004Deepak Khanna M.D. In the current study, we describe an adult patient with torrential aortic regurgitation due to an aortic dissection flap interfering with aortic cusp motion, in whom a transesophageal echocardiogram with the probe positioned in the upper esophagus and transpharyngeal ultrasound examination demonstrated prominent reversed flow throughout diastole in the left subclavian, left vertebral, left common carotid, and left internal carotid arteries. Another unique finding was the demonstration of aortic valve leaflets held in the fully opened position in diastole by the dissection flap as it prolapsed into the left ventricular outflow tract, dramatically documenting the mechanism of torrential aortic regurgitation in this patient. (ECHOCARDIOGRAPHY, Volume 21, May 2004) [source] 5 DIAGNOSTIC PITFALLS IN THE ECHOCARDIOGRAPHIC EVALUATION OF HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY (HOCM) REFERRED FOR CATHETER INTERVENTIONAL THERAPYECHOCARDIOGRAPHY, Issue 1 2004G. Beer Introduction: Generally, the diagnosis of typical HOCM with subaortic obstruction and a dynamic pressure gradient across the left ventricular outflow tract is made by noninvasive diagnostic procedures with great certainty by employing transthoracic (TTE) and/or transoesophageal (TEE) echocardiography. However, in patients with asymmetric septal hypertrophy pitfalls in echocardiographic examination may arise from several additional diseases as described in casuistic reports. To date systematic investigations in patients referred for catheter interventional therapy of HOCM are lacking. Patients and Methods: Therefore we investigated for the first time in a systematic study 200 symptomatic patients. (180 consecutive and 20 nonconsecutive patients; functional class 3 or 4 according to NYHA) with HOCM who were referred for this new catheter interventional therapy. In all patients TTE, bicycle exercise Doppler echocardiography and multiplane TEE were performed. Results: In 4 of 180 consecutive patients. (2.2%) discrete subvalvular membranous aortic stenosis (DSAS) (3 female patients and 1 male patient; age 20 to 58 years; mean septal diameter 19 mm; Sam-like motion in all 4 patients) was made. In all cases the diagnosis could be confirmed by surgical treatment. TEE evaluation was of crucial importance with demonstration of a typical subvalvular membrane that was situated a few millimeters below the aortic valve. In all cases a typical asymmetric septal hypertrophy mimicking HOCM was seen. Additionally, in 2 patients there was a conincidence of severe symptomatic valvular aortic stenosis and HOCM and in 1 patient a tunnel type of subvalvular aortic stenosis was present. Conclusion: These results show the potential pitfalls in echocardiographic diagnosis of HOCM. Especially, the frequency of DSAS in symptomatic patients referred for HOCM is unexpectedly high (2.2%). Especially in patients in whom TTE is of insufficient quality, investigation employing multiplane TEE with careful evaluation of the small poststenotic subvalvular area in HOCM is of crucial importance. This is of special significance prior to catheter interventional therapy, because in these patients surgical treatment is mandatory. [source] The Rupture of Periaortic Infective Aneurysm into the Left Atrium and the Left Ventricular Outflow Tract: Preoperative Diagnosis by Transthoracic EchocardiographyECHOCARDIOGRAPHY, Issue 3 2002Ewa Lastowiecka M.D. We present a rare complication of infective endocarditis, perforated periaortic abscess with fistulous communication between the aortic root, the left atrium, and the left ventricular outflow tract. Preoperative transthoracic echocardiographic diagnosis was confirmed intraoperatively. The patient was treated successfully by aortic homograft implantation. [source] Critical Left Ventricular Outflow Tract Obstruction Due to Accessory Mitral Valve TissueECHOCARDIOGRAPHY, Issue 2 2000RAFFAELE CALABRO M.D. Left ventricular outflow tract (LVOT) obstruction due to anomalous tissue tag arising from the mitral valve is a rare congenital cardiac anomaly. It generally becomes symptomatic during the first decade of life as exercise intolerance, chest pain, or syncope at effort. To date, only a few cases of critical systemic obstruction due to isolated mitral valve anomaly in neonates have been reported. We report the case of a neonate who was a few hours old and was referred in severe clinical condition due to critical left ventricular outflow obstruction resulting from an anomalous tissue tag of mitral valve origin. [source] Normal embryonic development and cardiac morphogenesis in mice with Wnt1-Cre-mediated deletion of connexin43GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 6 2006M. Kretz Abstract Mice harboring a null mutation in the gap junction protein connexin43 (Cx43) die shortly after birth due to an obstruction of the right ventricular outflow tract of the heart. These hearts exhibit prominent pouches at the base of the pulmonary outlet, i.e., morphological abnormalities that were ascribed to Cx43-deficiency in neural crest cells. In order to examine the Cx43 expression pattern in neural crest cells and derived tissues and to test whether neural crest-specific deletion of Cx43 leads to the conotruncal defects seen in Cx43null mice, we ablated Cx43 using a Wnt1-Cre transgene. Deletion of Cx43 was complete and occurred in neural crest cells as well as in neural crest-derived tissues. Nevertheless, hearts of mice lacking Cx43 specifically in neural crest cells were indistinguishable from controls. Thus, the morphological heart abnormalities of Cx43 null mice are most likely not caused by lack of Cx43 in neural crest cells. genesis 44:269,276, 2006. © 2006 Wiley-Liss, Inc. [source] Retinoid signaling and cardiac anteroposterior segmentationGENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 3 2001José Xavier-Neto Abstract Summary: Establishment of anterior,posterior polarity is one of the earliest decisions in cardiogenesis. Specification of anterior (outflow) and posterior (inflow) structures ensures proper connections between venous system and inflow tract and between arterial tree and outflow tract. The last few years have witnessed remarkable progress in our understanding of cardiac anteroposterior patterning. Molecular cloning and subsequent studies on RALDH2, the key embryonic retinaldehyde dehydrogenase in retinoic acid (RA) synthesis, provided the missing link between teratogenic studies on RA deficiency and excess and normal chamber morphogenesis. We discuss work establishing the foundations of our current understanding of the mechanisms of cardiac anteroposterior segmentation, the reasons why early evidence pointing to the role of RA in anteroposterior segmentation was overlooked, and the key experiments unraveling the role of RA in cardiac anteroposterior segmentation. We have also integrated recent experiments in a model of cardiac anteroposterior patterning in which RALDH2 expression determines anteroposterior boundaries in the heart field. genesis 31:97,104, 2001. © 2001 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||