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Atrial Septum (atrial + septum)

Distribution by Scientific Domains

Medical Sciences	93%

Selected Abstracts

Atrial Tachycardia Originating from the Upper Left Atrial Septum: Demonstration of Transseptal Interatrial Conduction Using the Infolded Atrial Walls

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2006
KOJI KUMAGAI M.D.
We report a rare case of atrial tachycardia (AT) originating from the upper left atrial septum. Electroanatomic mapping of both atria demonstrated that the earliest atrial activation during AT occurred at the upper left atrial septum 26 msec before the onset of the P wave, followed by the mid-right atrial septum (10 msec before the onset of the P wave) and then the upper right atrial septum just adjacent to the left septal AT site (1 msec before the onset of the P wave), indicating detour pathway conduction from the upper left to the upper right atrium. Embryologically, it was suggested that the superior components of the secondary atrial septum are made by the infolded atrial walls and could develop a transseptal detour pathway involving the left-side atrial septal musculature, the superior rim of the oval fossa and the right-side atrial septal musculature. A single radiofrequency application targeting the upper left atrial septum successfully abolished the AT. [source]

Platelet-derived growth factors in the developing avian heart and maturating coronary vasculature

DEVELOPMENTAL DYNAMICS, Issue 4 2005
Nynke M.S.
Abstract Platelet-derived growth factors (PDGFs) are important in embryonic development. To elucidate their role in avian heart and coronary development, we investigated protein expression patterns of PDGF-A, PDGF-B, and the receptors PDGFR-, and PDGFR-, using immunohistochemistry on sections of pro-epicardial quail,chicken chimeras of Hamburger and Hamilton (HH) 28,HH35. PDGF-A and PDGFR-, were expressed in the atrial septum, sinus venosus, and throughout the myocardium, with PDGFR-, retreating to the trabeculae at later stages. Additionally, PDGF-A and PDGFR-, were present in outflow tract cushion mesenchyme and myocardium, respectively. Small cardiac nerves and (sub)epicardial cells expressed PDGF-B and PDGFR-,. Furthermore, endothelial cells expressed PDGF-B, while vascular smooth muscle cells and interstitial epicardium-derived cells expressed PDGFR-,, indicating a role in coronary maturation. PDGF-B is also present in ventricular septal development, in the absence of any PDGFR. Epicardium-derived cells in the atrioventricular cushions expressed PDGFR-,. We conclude that all four proteins are involved in myocardial development, whereas PDGF-B and PDGFR-, are specifically important in coronary maturation. Developmental Dynamics 233:1579,1588, 2005. © 2005 Wiley-Liss, Inc. [source]

Observer Variation in the Echocardiographic Measurement of Maximum Atrial Septal Excursion: A Comparison of M-Mode with Two-Dimensional or Transesophageal Echocardiography

ECHOCARDIOGRAPHY, Issue 10 2009

Background: Atrial septal aneurysm is typically diagnosed by transthoracic two-dimensional or transesophageal echocardiography (2DE or TEE). Such techniques are highly dependent on visual inspection which predisposes to observer variation. This study compares inter- and intraobserver variations in the measurement of maximum atrial septal excursion (MASE) obtained using transthoracic M-mode echocardiography (MME) with that obtained using 2DE or TEE. Methods: Consecutive patients with highly mobile atrial septal motion by visual inspection during 2DE or TEE were studied. MASE was estimated visually on 2DE or TEE. MME tracings were obtained with the cursor bisecting the parabola formed by the atrial septum at its maximum deviation from the midline. Electronic calipers were used to measure MASE for all echocardiographic techniques. Two observers provided two measurements each. Observer variation was determined by assessing standard deviation and confidence intervals of inter- and intraobserver differences. Results: Interobserver analysis showed standard deviations of 0.077 cm (95% CI 0.065,0.094) for MME and 0.280 cm (95% CI 0.242,0.334) for 2DE or TEE. Intraobserver analysis showed standard deviations of 0.08 cm (95% CI 0.068,0.101) for MME and 0.318 cm (95% CI 0.274,0.381) for 2DE or TEE. The mean magnitude of measured MASE was 0.44 cm higher with MME than with 2DE or TEE (95% CI 0.068,0.101). Conclusions: MME assessment of MASE is associated with substantially lower inter- and intraobserver variation than 2DE or TEE assessment. The magnitude of MASE is substantially higher with MME than with 2DE or TEE. [source]

Atrial Tachycardia Originating from the Upper Left Atrial Septum: Demonstration of Transseptal Interatrial Conduction Using the Infolded Atrial Walls

Atrial Morphology in Hearts with Congenitally Corrected Transposition of the Great Arteries: Implications for the Interventionist

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2002
RAJNISH JUNEJA M.D.
Atrial Morphology in Congenitally Corrected Transposition.Introduction: In view of the possible need for septal puncture to ablate left-sided lesions and the occasional difficulty in coronary sinus (CS) cannulation, we investigated relevant anatomic features in the right atrium of hearts with congenitally corrected transposition of the great arteries (ccTGA). Methods and Results: Nine hearts with ccTGA and an intact atrial septum and eight weight-matched normal hearts were examined by studying the "septal" aspect of the right atrium with reference to the oval fossa (OF). The anterior margin was arbitrarily measured as the shortest distance from the OF to the superior mitral/tricuspid annulus. The posterior margin was measured from the OF to the posterior-most edge of the right atrial "septal" surface. The total "septal" surface width was measured at the middle of the OF. The stretched OF dimensions and CS isthmus length were noted. Mann-Whitney test was used to compare absolute and indexed dimensions, i.e.. normalized to total width. The posterior margin in hearts with ccTGA was shorter than in controls (6.3 ± 2.4 mm vs 11 ± 1.9 mm, P < 0.001; normalized margin P = 0.09). The CS isthmus also was significantly shorter (5.3 ± 2.7 mm vs 11.4 ± 2.2 mm, P < 0.001). In two hearts with ccTGA, the CS opening into the right atrium was on the same side of the eustachian valve as the inferior caval vein. Conclusion: The shorter posterior "septal" margin in hearts with ccTGA may increase the risk of exiting the heart while performing septal puncture when pointing the needle posteriorly. The shorter CS isthmus and the abnormal location of the CS opening in some of these hearts are important when contemplating radiofrequency ablation in this area. [source]

Variance of Peptidic Nerve Innervation in a Canine Model of Atrial Fibrillation Produced by Prolonged Atrial Pacing

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2008
XIUFEN QU Ph.D.
Background:Long-term rapid atrial pacing may result in nerve sprouting and sympathetic hyperinnervation in atrial fibrillation (AF) in dogs. Whether peptidic nerve is involved in neural remodeling is unclear. Method and Results:We performed rapid left atrial pacing in six dogs to induce sustained AF. Tissues from six healthy dogs were used as controls. Nerve was identified by immunocytochemical techniques. The degree of nerve innervation was quantified by measuring the amount of staining area for each antibody and the heterogeneity of nerve distribution was qualitatively studied. In dogs with AF, the density of growth-associated protein 43 (GAP43) immunopositivenerve fibers in the left atrium (LA), atrial septum (AS), and right atrium (RA) was significantly (19,454.31 ± 1,592.81 ,m2/mm2 vs 1,673.41 ± 142.62 ,m2/mm2P < 0.001, 3,931.26 ± 361.78 ,m2/mm2 vs 1,614.20 ± 140. 41 ,m2/mm2 P < 0.05 and 2,324.15 ± 1,123.77 ,m2/mm2 vs 1,620.47 ± 189.05 ,m2/mm2 P < 0.05, respectively) higher than the nerve density in control tissues. The density of (neuropeptide Y) NPY-positive nerves in the, AS, and RA was (13,547.62 ± 2,983.37 ,m2/mm2 vs 703.72 ± 287.52 ,m2/mm2 P < 0.01, 2,689.22 ± 340.93 ,m2/mm2 vs 651.7 ± 283.02 ,m2/mm2 P < 0.01 and 1,574.70 ± 424.37 ,m2/mm2 vs 580.42 ± 188.12 ,m2/mm2 P < 0.001, respectively) higher than the nerve density in control tissues. At the same time, vasoactive intestinal polypeptide (VIP) positive nerve innervation shrank in dogs with AF. The density of VIP positive in LA, AS, and RA was statistically lower than the nerve density in control tissues, respectively. (110.48 ± 45.63,m2/mm2 vs 1679.32 ± 1020.34,m2/mm2 P < 0.01, 265.92 ± 52.51 ,m2/mm2 vs 2602.68 ± 1257.16,m2/mm2 P < 0.001 and 609.56 ± 139.75,m2/mm2 vs 2771.68 ± 779.08,m2/mm2 P < 0.01, respectively) Conclusions:Combined with VIP-ergic nerve denervation, significant nerve sprouting and NPY-ergic nerve hyperinnervation are present in a canine model of sustained AF produced by prolonged atrial pacing. [source]

Management of a cadaveric orthotopic liver transplantation in a pediatric patient with complex congenital heart disease

PEDIATRIC ANESTHESIA, Issue 6 2006
DENNIS E. FEIERMAN MD PhD
Summary Pediatric orthotopic liver transplantations (OLT) are commonly performed nowadays. Two primary reasons for OLT in children are complications from either extrahepatic biliary atresia (EHBA) or inborn errors of metabolism. However, congenital liver disease may be associated with significant other congenital abnormalities. We present a case of a successful OLT in a pediatric patient with a history of EHBA, situs inversus, and complex congenital heart disease. The cardiac anomalies include dextrocardia, absence of the atrial septum (single atrium), single atrioventricular valve (a-v canal), and an incomplete ventricular septum. Prior surgery include a Kasai procedure for EHBA, banding of the proximal main pulmonary artery, and Broviac catheter placement. We present the anesthesia concerns and management for this complicated case. [source]

Transthoracic echocardiographic assistance for interatrial stenting in low birth-Weight neonates with hypoplastic left heart syndrome and intact atrial septum,

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2010
Christopher J. Petit MD
Abstract Infants with hypoplastic left heart syndrome and intact or highly restrictive atrial septum require emergent therapy to relieve pulmonary congestion. Transcatheter stenting has become, in most large centers, the mainstay of therapy for relief of left atrial hypertension. Normally, this procedure is performed with the assistance of transesophageal echocardiographic guidance. However, the transesophageal approach is untenable in neonates of low birth weight, as the transducers can be traumatic and can cause ventilatory difficulty. We present two cases in which transthoracic echocardiographic guidance was used to guide atrial perforation and stenting in low birth-weight neonates with hypoplastic left heart syndrome with intact or highly restrictive atrial septum. Both procedures were straightforward and there were no complications. Real-time biplane imaging greatly assisted in the intervention in one case. The advantages of this approach are discussed. © 2010 Wiley-Liss, Inc. [source]

Biodisk: A new device for closure of patent foramen ovale: A feasibility study in swine,

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 6 2010
Dusan Pavcnik MD
Abstract Purpose: To evaluate the feasibility, effectiveness, and safety of a porcine small intestinal submucosa (SIS)-covered Biodisk (BD) for the closure of patent foramen ovale (PFO) in swine. Methods: Twelve piglets (9,30 kg) with PFO ranging in size from 6 to 12 mm were used for the in vivo testing. The BD device consisted of two basic nitinol wire components covered with platinum coil, a flexible SIS-covered ring, and an anchor. The BD was advanced through an 8-Fr sheath from the femoral vein. Nine acute animals were used to test the BD for deployment, stability, immediate shunt closure, and device repositioning before or after its detachment. To assess retrievability, four devices were deployed and intentionally embolized into the RA (n = 2) and LA (n = 2). The effectiveness of the device was evaluated by angiocardiography. EKG was recorded before and after PFO closure for 3 hr. From the 12 animals, nine were acute and three were followed; one for 6 weeks, one for 12 weeks, and one for 16 weeks. Results: Successful device implantation was achieved in all animals with no shunting of contrast media observed during follow-up in. One animal needed to have device repositioned for complete PFO occlusion because of suboptimal placement at the first attempt. The device was easily placed and retrieved before detachment in all nine animals in the acute study. None of the BDs spontaneously embolized during release or on follow-up. EKG did not demonstrate arrhythmias during or after treatment. Four intentionally embolized BDs were easily retrieved with an Amplatz goose neck snare. Macroscopic and histologic evaluation of the three long-term animals showed that devices were well incorporated in the atrial septum with complete shunt closure. The SIS showed progressive remodeling with the host cells. There was also progressive endothelization of the BD device. Conclusion: The BD device deployment is feasible, safe, and effective. Long-term studies are needed to evaluate its long-term effectiveness. © 2010 Wiley-Liss, Inc. [source]

Atrial septal interventions in patients with hypoplastic left heart syndrome,

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 5 2008
Ralf J. Holzer MD
Abstract Objectives: To report an institutional experience performing percutaneous atrial septal interventions in patients with hypoplastic left heart syndrome (HLHS). Background: The success of the Hybrid approach in palliating patients with HLHS is crucially dependant on relieving any significant interatrial restriction. Data on transcatheter interventions to relieve atrial septal restrictions in patients with HLHS are limited. Methods: We retrospectively reviewed 67 transcatheter atrial septal interventions that were performed between July 2002 and September 2007 in 56 patients with HLHS. The median weight was 3.35 kg. About 10.7% of patients had an intact atrial septum. Balloon atrial septostomy (BAS) was used in 77.6% of procedures, additional techniques in 35.8% of procedures. Patients were divided into those with standard atrial septal anatomy (group A, n = 33) and those with complex atrial septal anatomy (group B, n = 23). Results: The mean trans-septal gradient was reduced significantly from 7 mm Hg to 1 mm Hg with the median time to discharge being 3.5 days. Major adverse events were seen in 8.9% of procedures, whereas minor adverse events occurred in 26.8% of procedures. Adverse events were significantly less common in patients with standard atrial septal anatomy, compared to those with complex atrial septal anatomy (25.6% versus 50.0%). About 19.6% patients required repeated atrial septal interventions. Survival up to and including Comprehensive stage II palliation was 73% group A, and 57% in group B. Conclusions: With utilization of appropriate techniques and equipment, atrial septal interventions in HLHS can be performed successfully in virtually all patients. Complex atrial septal anatomy is technically challenging and has a higher incidence of procedural adverse events. In the majority of patients, standard BAS can be performed safely, and is usually the only intervention required to achieve adequate relief of atrial septal restriction until Comprehensive stage II palliation. © 2008 Wiley-Liss, Inc. [source]

New transcatheter techniques for creation or enlargement of atrial septal defects in infants with complex congenital heart disease

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 5 2007
Carlos A.C. Pedra MD
Abstract Objectives: To describe a series of 8 consecutive infants (5 with transposition of the great arteries [TGA] and 3 with hypoplastic left heart syndrome [HLHS]) who underwent nonconventional septostomy techniques. Background: For some complex congenital heart defects, an unrestrictive atrial septal defect (ASD) is essential to achieve an adequate cardiac output and/or systemic saturation. In some scenarios, the use of conventional septostomy techniques may be technically difficult, hazardous, and/or ineffective. Methods: Use of transhepatic approach, cutting balloons, and radiofrequency perforation with stenting of the atrial septum. Results: The size of the ASD and the oxygen saturation increased in all patients with no major complications. In those with TGA, the ASDs were considered to be of good size at the arterial switch operation. Two of the 3 patients with hybrid palliation for HLHS have developed some degree of obstruction within the interatrial stent over 2,3 months. At surgery, the stents were found to be secured within the septum with one showing significant fibrous ingrowth after uneventful removal. The other had some nonobstructive ingrowth. Conclusions: Creation or enlargement of ASDs in infants using new nonconventional transcatheter techniques is feasible, safe, and effective, at least in the short-to-mid-term follow-up. Infants with TGA seem to benefit the most because the procedure results in satisfactory clinical stability for subsequent early surgical intervention. In infants with HLHS palliated by a hybrid approach, stent implantation to the atrial septum seems to buy enough time to bring them to the phase II safely despite progressive in-stent obstruction. © 2007 Wiley-Liss, Inc. [source]

Blunt atrial transseptal puncture using excimer laser in swine,

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2007
Abdalla A. Elagha MD
Abstract Objectives: We describe a new approach that may enhance safety of atrial transseptal puncture using a commercially available laser catheter that is capable of perforation only when energized. We test this approach in swine. Background: Despite wide application, conventional needle transseptal puncture continues to risk inadvertent nontarget perforation and its consequences. Methods: We used a commercial excimer laser catheter (0.9-mm Clirpath, Spectranetics). Perforation force was compared in vitro with a conventional Brockenbrough needle. Eight swine underwent laser transseptal puncture under X-ray fluoroscopy steered using a variety of delivery catheters. Results: The 0.9-mm laser catheter traversed in vitro targets with reduced force compared with a Brockenbrough needle. In vitro, the laser catheter created holes that were 25,30% larger than the Brockenbrough needle. Laser puncture of the atrial septum was successful and accurate in all animals, evidenced by oximetry, pressure, angiography, and necropsy. The laser catheter was steered effectively using a modified Mullins introducer sheath and using two different deflectable guiding catheters. The mean procedure time was 15 ± 6 min, with an average 3.0 ± 0.8 sec of laser activation. There were no adverse sequelae after prolonged observation. Necropsy revealed discrete 0.9-mm holes in all septae. Conclusion: Laser puncture of the interatrial septum is feasible and safe in swine, using a blunt laser catheter that perforates tissues in a controlled fashion. © 2007 Wiley-Liss, Inc. [source]

Percutaneous fenestration closure with problematic residual native atrial septum

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2005
Abraham Rothman MD
Abstract A variety of techniques have been utilized to close Fontan fenestrations. Among 20 patients who underwent a cardiac catheterization for fenestration closure, 3 patients had residual native atrial septum, forming an additional intermediate chamber on the pulmonary venous side of the fenestration. Three different methods were used to close these fenestrations. © 2005 Wiley-Liss, Inc. [source]