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At least 19 recordsLinked to original sources

The hypoplastic left heart syndrome with intact atrial septum: atrial morphology, pulmonary vascular histopathology and outcome.

OBJECTIVES: The purpose of this study was to investigate the outcome in infants with hypoplastic left heart syndrome and intact atrial septum and to evaluate the relationship of atrial morphology, left atrial decompression pathway and lung histopathology to outcome. BACKGROUND: In the hypoplastic left heart syndrome, severe restriction at the atrial level results in marked systemic hypoxemia after birth. Infants with intact atrial septum may be at high risk for mortality after Norwood operation. METHODS: Of 316 infants with hypoplastic left heart syndrome seen at our center over a 6.5-year period, 18 (5.7%) had intact atrial septum. Medical records and echocardiograms were reviewed. RESULTS: On echocardiography, three types of intact atrial septal morphology were identified: 1) large left atrium, thick prominent septum secondary with thin septum primary adherent (type A, n = 12); 2) small left atrium with thick, muscular atrial septum (type B, n = 4), and 3) giant left atrium, thin atrial septum with severe mitral regurgitation (type C, n = 2). Seven infants had left atrial decompression pathways that were severely obstructed (3/12 type A, 4/4 type B). Norwood operation was performed in 17 infants; one underwent emergency balloon atrial septostomy and died. Of six early survivors, all with type A atrial morphology and unobstructed decompression pathway, three died after subsequent cavopulmonary surgery. Lung histopathology revealed severely dilated lymphatics and "arterialization" of the pulmonary veins in those with the severest degree of obstruction to left atrial egress (type B atrial morphology). CONCLUSIONS: Despite aggressive intervention, outcome for infants born with hypoplastic left heart syndrome and intact atrial septum is poor. Maldevelopment of the pulmonary vasculature contributes to the high mortality seen. Atrial morphology can be used as a marker for the severity of pulmonary vascular disease.

Heart Atria↗

Comparison of the acute effects of pacing the atrial septum, right atrial appendage, coronary sinus os, and the latter two sites simultaneously on the duration of atrial activation.

OBJECTIVE: To compare the acute effects of right atrial appendage, atrial septal, coronary sinus os, and dual site pacing on the duration of atrial activation. METHODS: 20 patients with a variety of cardiac conditions underwent an intracardiac electrophysiological study. Electrograms were recorded from the right atrial appendage and at multiple sites within the coronary sinus. The duration of atrial activation was measured during pacing at the right atrial appendage, atrial septum, and coronary sinus os, and also during dual site stimulation. RESULTS: The duration of atrial activation with atrial appendage pacing was notably longer (p < 0.001) than with dual site, septal, or coronary sinus os pacing, but there were no significant differences in atrial activation times between these latter three pacing modes. When stimulating the atria at a cycle length of 500 ms, the mean (SD) duration of atrial activation was 145 (37) ms for right atrial appendage pacing, 93 (26) ms for dual site pacing, 96 (28) ms for septal pacing, and 98 (28) ms for coronary sinus os pacing. CONCLUSIONS: Assuming that the duration of atrial activation is an important determinant of predisposition to paroxysmal atrial fibrillation, atrial septal pacing or coronary sinus os pacing would appear to offer the same advantage as dual site pacing without the additional complexities associated with the latter pacing mode.

Adult↗

Lipomatous hypertrophy of the atrial septum presenting as a right atrial mass.

Lipomatous hypertrophy of the atrial septum (LHAS) has been associated with cardiac arrhythmias and is defined as fatty infiltration > 2 cm thick in the atrial septum. The clinical and histologic features of surgically excised LHAS have not been previously studied. We studied 11 surgical resections of LHAS and compared them with 13 autopsy cases of LHAS and 24 control autopsy hearts. Of 11 surgical patients, eight were women: patients' mean age was 63 years, and six were described as mildly to overtly obese. Symptoms included congestive heart failure, atrial fibrillation, supraventricular tachycardia, palpitations, syncope, and incidental mass found at surgery. Imagining studies typically revealed a right atrial mass with a mean size of 6 cm (range, 2.5-10 cm). Multivacuolated fat was more extensive in surgical (p = 0.005) and autopsy (p = 0.009) cases of LHAS than in control hearts. Atypical, hypertrophied myocytes were presented in 72% of cases of LHAS compared with 8% of controls (p = 0.0003). In autopsy hearts, histologically abundant multivacuolated fat, heart weight, and body size were independently associated with increased atrial septal thickness. LHAS can be surgically excised, it has a distinctive histologic appearance marked by the presence of abundant multivacuolated fat and hypertrophied myocytes, and it is associated with increased body and cardiac mass.

Adipocytes↗

Computerized activation sequence mapping of the human atrial septum.

To delineate the propagation of electrical activation in the atrial septum, atrial epicardial and atrial septal maps were recorded intraoperatively using a 156-channel computerized mapping system in 12 patients during sinus rhythm (n = 10), supraventricular tachycardia associated with septal pathways in Wolff-Parkinson-White syndrome (n = 3), atrioventricular (AV) node reentrant tachycardia (n = 4), and atrial flutter (n = 5). The epicardial and septal data were recorded simultaneously from 156 atrial electrodes, digitized, analyzed, and displayed as isochronous maps on a two-dimensional diagram of the atria. During sinus rhythm, the activation wave fronts propagated most rapidly along the large muscle bundles of the atrial septum. During supraventricular tachycardia associated with Wolff-Parkinson-White syndrome, the earliest site of retrograde atrial activation usually corresponded to the position of atrial insertion of the septal pathways. However, the earliest site of activation during orthodromic supraventricular tachycardia was different from that during ventricular pacing in 1 patient with a posterior septal accessory pathway localized by the epicardial mapping study. The data document the rationale for dividing the ventricular end of the accessory pathways (ie, the endocardial technique) rather than the atrial end (ie, the epicardial technique) in patients with Wolff-Parkinson-White syndrome. During AV node reentrant tachycardia, atrial activation data suggested that atrial tissue lying outside the confines of the anatomical AV node is a necessary link in this common arrhythmia. Thus, these atrial septal maps explain why surgical dissection, or properly positioned small cryolesions placed in the region of the AV node, can ablate AV node reentrant tachycardia without altering normal AV node function. The maps recorded during atrial flutter suggest the importance of the atrial septum as one limb of a macroreentrant circuit responsible for the arrhythmia, and imply that atrial flutter is amenable to control by surgical techniques. These studies demonstrate the details of normal atrial septal activation, the importance of the atrial septum in a variety of different atrial arrhythmias, and the basis of and potential for surgical ablation of the most common types of supraventricular arrhythmias.

Adolescent↗

Surgical isolation of the atrial septum from the atria. Identification of an atrial septal pacemaker.

This is a report of the third in a series of experiments carried out to identify and to determine the reliability of atrial pacemakers below the sinoatrial (SA) node. This information could be useful to the surgeon in planning both corrective atrial operations and direct operations for atrial arrhythmias. In this study, done in dogs, the atrial septum containing the atrioventricular (AV) node was completely separated from the remaining atria. Seven dogs survived for 35 to 116 days. Serial electrocardiograms (ECGs) after operation showed that four of the seven dogs developed a regular junctional rhythm with a rate of 85 beats/min, whereas three of seven developed an irregular junctional rhythm with pauses and bigeminy. In a control study, in which the AV node was disconnected from the His bundle, a slow regular junctional rhythm was produced in all three of the dogs. Thus, in the series of three experiments, this being the report of the last one, a hierarchy of pacemakers below the SA node was identified. The first one, a pacemaker in the low right atrium in the region of the coronary sinus, was the most reliable and was associated with a normal ECG. A second, in the atrial septum, did not develop dominance in all dogs. However, the junctional pacemaker in the His bundle always became dominant after the AV node was disconnected from the His bundle and was associated with a regular but slow rhythm.

Animals↗

Prolapsing large aneurysm of the atrial septum simulating a right atrial mass.

An unusual case of a large, prolapsing atrial septal aneurysm in a patient with an otherwise normal heart is described. The aneurysm caused right atrial obstruction and resulted in a "tumor effect." The patient experienced debilitating symptoms for years before receiving an appropriate diagnosis and curative surgical treatment.

Blood Vessel Prosthesis↗

Intra-uterine closure of the atrial septum.

Two newborn babies with an intact atrial septum are described. In one, the two components of the atrial septum appeared to have become fused after relatively normal initial development; the left side of this heart was hypoplastic. In the other baby the formation of the atrial septum appeared to have been completely anomalous; this heart showed mitral atresia, absence of the left ventricle, and transposition of the great vessels. There was also pulmonary lymphangiectasis in the second case, and it is suggested that this was due to the cardiac malformation obstructing pulmonary venous drainage.

Female↗

Lipomatus hypertrophy of the atrial septum and prominent crista terminalis appearing as a right atrial mass.

In these case reports, transthoracic echocardiography suggested the presence of a right atrial mass. However, subsequent transoesophageal echocardiography revealed that the 'right atrial mass' was actually a lipomatous hypertrophied atrial septum in combination with a prominent crista terminalis. An understanding of the anatomy and the echocardiographic appearance of a lipomatous hypertrophied atrial septum appearing with a prominent crista terminalis will minimize the misdiagnosis of these structures.

Aged↗

Clinical, electrocardiographic and morphologic features of massive fatty deposits ("lipomatous hypertrophy") in the atrial septum.

OBJECTIVES: This study examined the morphologic features and the clinical significance of massive fatty deposits in the atrial septum of the heart. BACKGROUND: Large deposits of adipose tissue in the atrial septum were first described in 1964 and have been referred to as "lipomatous hypertrophy" of the atrial septum. A relation between these fatty deposits and atrial arrhythmias has been suggested. METHODS: The thickness of the atrial septum cephalad to the fossa ovalis ranged from 1.5 to 6 cm in 91 patients and was > or = 2 cm in 80 patients. This report focuses primarily on the latter 80 patients. RESULTS: The thickness of the atrial septum in the 80 patients correlated with body weight and the thickness of the adipose tissue in the atrioventricular groove and that covering the right ventricle. In 53 patients (67%), one or more of the four major epicardial coronary arteries were narrowed > 75% in cross-sectional area by atherosclerotic plaque. Atrial arrhythmias were present in 31 patients (40%). Patients with larger deposits of fat (atrial septal thickness > or = 3 cm) had a higher frequency of atrial arrhythmias (60% vs. 34%, p < 0.01). The atrial septum was significantly thicker in patients with atrial arrhythmia compared with those without atrial arrhythmias (2.9 vs. 2.3 cm, p < 0.01). Of the 28 patients with available electrocardiograms, 20 (71%) showed atrial arrhythmias (nine atrial premature complexes, seven atrial fibrillation, three atrial tachycardia, one ectopic atrial rhythm and one junctional rhythm). CONCLUSIONS: Massive fatty deposits in the atrial septum are associated with large deposits of fat elsewhere in the body and other parts of the heart. They are frequently associated with atrial arrhythmias and atherosclerotic coronary artery disease.

Aged↗

Diagnosis of lipomatous hypertrophy of the atrial septum by two-dimensional echocardiography.

Originally described in 1964, lipomatous hypertrophy of the atrial septum currently remains a diagnosis established primarily at autopsy. Clinical interest in this disorder has centered on the reported association with supraventricular arrhythmias and sudden death. Because two-dimensional echocardiography allows detailed assessment of atrial septal configuration, we reviewed two-dimensional echocardiographic reports obtained over a 1 year period and identified 17 patients who had features consistent with lipomatous hypertrophy of the atrial septum. Nine were men and the average age was 70 years. Autopsy confirmation of the echographic findings was possible in one patient. In nine patients, ideal body weight was exceeded by 10% or more. The atrial septum viewed from the subcostal transducer position showed a distinctive echo-dense globular thickening sparing the valve of the fossa ovalis. The resultant tomographic image of the atrial septum had a characteristic dumbbell appearance. The mean thickness of the atrial septum was 21 mm (range 15 to 29). Seven patients had supraventricular arrhythmias, and eight had P wave abnormalities. The two-dimensional echocardiographic features described are distinctive and suggest that this technique is the procedure of choice not only for establishing the diagnosis of lipomatous hypertrophy of the atrial septum but also for providing a means for prospective follow-up of patients with this little known entity.

Aged↗

The normal anatomy of the atrial septum in the human heart.

The atrial septum is a blade-shaped structure with a concave anterior margin that reflects the curve of the ascending aorta, a convex posterior margin, and an inferior margin along the mitral annulus. The fossa ovalis comprises an average of 28 per cent of the total septal area, or 43 mm.2 in infants and 240 mm.2 in adults. The channel that persists between the fossa ovalis and the muscular atrial septum is patent except at the limbus, providing a useful explanation for the success of blunt transseptal atrial catheterization and right-to-left shunts in individuals with elevated right atrial pressure.

Adolescent↗

[Aneurysms of the atrial septum].

Aneurysms of the atrial septum (ASA) frequently diagnosed since the introduction of transoesophageal echocardiography are implicated in the aetiology of cerebral and systemic embolic events. This update was undertaken to resume recent data on this pathology and its relationship with embolic events. The diagnostic criteria are described together with the morphological features (size, movements, thickness) and associated abnormalities (interatrial shunts, valvular prolapse). The authors summarise the data concerning possible complications of ASA, especially the different mechanisms invoked to explain embolism (paradoxical embolism. thrombosis in situ, supraventricular arrhythmias). Therapeutic options are discussed with respect to the clinical contexts (therapeutic abstention, platelet antiaggregant drugs, oral anticoagulants, interventional cardiology or surgery.

Adult↗

Three-dimensional ultrasound imaging of the atrial septum: normal and pathologic anatomy.

OBJECTIVES: This study investigated the feasibility of producing three-dimensional gray scale ultrasound images of the atrial septum to demonstrate normal and pathologic anatomy. BACKGROUND: Two-dimensional echocardiography is the principal technique used for imaging the atrial septum. Although the diagnostic accuracy of two-dimensional echocardiography is high, its capability for displaying complex three-dimensional relations is limited. METHODS: Three-dimensional ultrasound images were reconstructed from tomographic images obtained during routine transesophageal echocardiographic examinations. Custom-made semi-automatic algorithms for image enhancement, interpolation and segmentation were used to produce volumetric gray scale images. Volume-rendered displays of the atrial septum were generated for analysis. Sequential three-dimensional images were generated through the cardiac cycle and displayed cinematographically to permit assessment of motion. RESULTS: The three-dimensional images obtained from six patients clearly demonstrated normal and pathologic anatomy of the atrial septum, including atrial septal defects, atrial septal aneurysm and aortic valve ring abscess. The images could be manipulated electronically to demonstrate spatial relations and internal structural details. CONCLUSIONS: Three-dimensional gray scale reconstruction of ultrasound images obtained by transesophageal echocardiography is feasible. These images clearly demonstrate anatomic details and spatial relations. The gray scale images may be interactively manipulated to optimize the clinician's visualization of the atrial septum and its associated pathologic conditions.

Cardiomyopathies↗

A case report of "lipomatous hypertrophy of the cardiac interatrial septum", with a proposal for a new term "lipomatous hamartoma of the cardiac atrial septum".

An autopsy case of "lipomatous hypertrophy of the cardiac interatrial septum" (LHIS) combined with marked stenosis and calcification of the aortic and mitral valves due to fibrous valvular endocarditis, malignant lymphoma, and mucin-producing cancer of the pancreas is reported. LHIS and mucin-producing cancer of the pancreas were incidental findings at autopsy. Microscopically, the LHIS in this case consisted of proliferation of mature fat cells, brown fat cells and cardiac muscle cells. Since these three cell types are normal structural components of the interatrial septum, it was considered that the LHIS was a hamartomatous rather than hypertrophic lesion, of the cardiac atrial septum. Accordingly it was concluded that the term "lipomatous hamartoma of the cardiac atrial septum" was more appropriate for this lesion in the case presented here. As far as we know, this is the first reported case of LHIS in Japan.

Aged↗

[Lipomatous hyperthrophy of the atrial septum - two case reports].

Lipomatous hyperthrophy of the atrial septum is a rarely diagnosed but not rarely occurring benign hyperplasia of the lipomatous tissue. Apart from possible arrhythmias and single description of superior vena cava obstruction by extremely hypertrophied septum, lipomatous hyperthrophy does not seem to have any significant clinical importance. The potential danger is however associated with a false diagnosis of malignant tumor of the heart and unnecessary selection for cardiac surgery. We present two patients with the final diagnosis of benign lipomatous hyperthrophy of the atrial septum, referred to our center with an initial diagnosis of right atrial tumor.

Adipose Tissue↗

Intervention in the critically ill neonate and infant with hypoplastic left heart syndrome and intact atrial septum.

Neonates that present with hypoplastic left heart syndrome (HLHS) and intact atrial septum (IAS) pose a major management problem for the pediatric cardiac team. They are critically ill newborns with profound hypoxemia and acidosis that require immediate attention. Controversy exists as to the most appropriate management strategy. In one series where a primary and emergent surgical-staged reconstructive procedure was performed, the in-house hospital mortality was 65% and the overall survival was 17%. With equal abysmal results, transcatheter creation of an atrial septal defect (ASD) using conventional balloon atrial septostomy (BAS) with or without the combination of blade atrial septotomy had an unacceptable high risk of cardiac perforation leading to tamponade and death. However, using more modern transcatheter techniques of transseptal perforation of the atrial septum followed by progressive and serial balloon septoplasty, creating an ASD, significantly reduced the risk of the procedure. In one series, 16 consecutive neonates underwent this type of interventional procedure without procedural mortality. The management strategy of creating an ASD in the catheterization lab followed by Stage I reconstructive surgical repair 3-5 days after the initial catheterization procedure improved the in-house survival to 57%. Unfortunately, there continues to be significant attrition of these patients undergoing Stage II and III reconstructive repair, which supports cardiac transplantation as an alternative strategy. There have been echocardiographic and histopathologic studies of these neonates, and an important echo classification of left atrial morphology has been described with perhaps some prognostic implication. In addition, autopsy specimens have demonstrated significant "arterialization" of the pulmonary venous architecture that likely dooms the patient with single ventricle physiology to a poor outcome. Future improvement in transcatheter techniques and materials offer promise in palliating these critically ill neonates. The concept of radiofrequency energy perforating catheters has great merit and may reduce the risk of cardiac perforation as compared with the rigid and long transseptal needle. Echocardiographic imaging at the time of entry through the IAS may improve the safety as well. The novel concepts of "butterfly" or "dog-bone" stents placed across the atrial septum creates a precisely sized ASD that may be more conducive to effectively lower left atrial hypertension, yet avoids excessive pulmonary blood flow associated with large atrial communications. In addition, new materials, such as the Cutting Balloon Catheter, may offer promise in creating ASDs in these patients. A more aggressive approach would be to consider intrauterine fetal transcatheter opening of the IAS using modified techniques that have been attempted for left ventricular outflow tract obstruction. Unfortunately to date, the results of attempted relief of aortic valve stenosis have been extremely poor. Finally, we as interventionalists need to continue to improve our skills to help in the complex management of these critically ill neonates and infants. Only through continued efforts of the entire cardiac team of intensivists, cardiologists, cardiothoracic surgeons, and interventionalists will our management strategy be defined to maximize the future outcome in this group of patients.

Angiography↗

[A study of autonomic innervation of the atrial septum by iso-integral mapping in dogs].

Although neuronal cell bodies have been identified in the upper part of the atrial septum, the functional anatomy of its autonomic innervation remains unknown. To study parasympathetic inputs to the atrial septum, we performed isointegral distribution mapping using a 64-electrode balloon array inserted in the right atrium under cardiopulmonary bypass in 9 anesthetized mongrel dogs. Unipolar electrograms were recorded during stimulation of either the right or left vagus nerve or right atrialpulmonary vein ganglionated plexus before and after surgical ablation of tissues along the superior vena cava, of the right atrial-pulmonary vein ganglionated plexus, the aorto-pulmonary tissues and the inferior vena cava fat pad. Local neural effects were estimated from integral changes of each electrogram which were plotted on a septal grid to generate isointegral distribution maps. Changes were considered significant whenever integral differences exceeded twice the standard deviation of control values. Stimulation of the right and left vagi induced significant effects in the high atrial septum in 5 preparations and in the low septum in 6. These effects were suppressed by the dissection of tissues around the superior vena cava and ablation of the right atrial-pulmonary vein ganglionated plexus, but not by that of the inferior vena cava or the aorto-pulmonary tissues. Direct stimulation of the right atrial-pulmonary vein ganglionated plexus produced effects in the high and low septum in 8 and 4 preparations, respectively, which persisted after dissection around the superior vena cava, suggesting the existence of local circuit neural elements. We conclude that the canine atrial septum is innervated by axons from both vagi which course near the superior vena cava and converge through the right atrial-pulmonary vein ganglionated plexus and also by intrinsic neural elements independent of central parasympathetic efferents.

Animals↗