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At least 19 recordsLinked to original sources
PubMed1999

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↗
PubMed2000

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↗
PubMed1996

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↗
PubMed1990

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↗
PubMed2004

Hypoplastic left heart syndrome with intact or highly restrictive atrial septum: outcome after neonatal transcatheter atrial septostomy.

BACKGROUND: Hypoplastic left heart syndrome (HLHS) with intact or very restrictive atrial septum is a highly lethal combination. We review our 13-year institutional experience treating this high-risk subgroup of patients with emergent catheter therapy. METHODS AND RESULTS: Infants with HLHS requiring catheter septostomy within the first 2 days of life were compared with a matched control group with adequate interatrial communication. Preoperative, early postoperative, and medium-term survival were evaluated. Earlier experience was compared with recent results to assess the effect of changes in catheterization and surgical and intensive care unit management strategies over the study period. From 1990 to 2002, 33 newborns with HLHS (11% of newborns with HLHS managed during this period) underwent urgent/semiurgent catheterization to create or enlarge an interatrial communication before surgical palliation. Preoperative and early postoperative mortality were high (48%) compared with control HLHS patients, regardless of prenatal diagnosis and despite successful catheter-based atrial septostomy with clinical stabilization. Mortality trended down during the later part of the study period. Those who survived the neonatal period had late survival, pulmonary artery pressure, and resistance similar to those of control subjects. CONCLUSIONS: Neonatal mortality in the subgroup of HLHS patients with intact or highly restrictive atrial septum remains high despite successful urgent septostomy. Persistently poor outcomes for these patients have prompted efforts at our center to develop techniques for fetal intervention for this condition, in the hope that prenatal relief of left atrial and pulmonary venous hypertension may promote normal pulmonary vascular and parenchymal development and improve both short- and long-term outcomes.

Cardiac Catheterization↗
PubMed2006

Atrial tachycardia originating from the upper left atrial septum: demonstration of transseptal interatrial conduction using the infolded atrial walls.

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.

Aged↗
PubMed2005

Electrical characteristics of low atrial septum pacing compared with right atrial appendage pacing.

AIM: The study was designed to compare the electrical characteristics of atrial leads placed in the low atrial septum (LAS) with those placed in the right atrial appendage (RAA) associated with dual chamber pacing. METHODS: In 86 patients an active-fixation (St. Jude Medical's Tendril DX model 1388T) atrial lead was positioned in RAA and in 86 patients the same model atrial lead was placed in the LAS. Pacing thresholds, sensing thresholds, impedances and the Far Field paced R-Wave (FFRW) amplitude and timing were compared at 6 weeks and at 3 and 6 months. RESULTS: The pacing threshold did not differ between groups. Sensed voltage of the P-wave was higher in the LAS compared with the RAA at 3 and 6 months (P=0.004). Impedance was higher in the LAS at 6 weeks and 3 months (P=0.002) but this difference was no longer significant at 6 months (P=0.05). The atrial sensed FFRW voltage was significantly higher in the LAS position compared with the RAA at 3 and 6 months follow-up (P=0.0002). FFRW voltage>1 mV was seen in 87% of the RAA pacing group and in 94% of the LAS pacing group (P=ns). The time between the ventricular pacing stimulus and the sensed FFRW in the atrium, (V spike-FFRW) in RAA was longer than in LAS at all follow-up measurements (P=0.006). CONCLUSIONS: The electrical characteristics of LAS pacing makes this alternative position in the atrium safe and feasible. Though statistical differences were found in P-wave sensing (LAS higher voltage than in the RAA) and FFRW sensing was higher in the LAS compared with the RAA this did not interfere with the clinical applicability of the LAS as alternative pacing site.

Atrial Fibrillation↗
PubMed1980

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↗
PubMed1992

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↗
PubMed1966

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↗
PubMed2002

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↗
PubMed1993

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↗
PubMed1983

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↗
PubMed2004

Creation of an atrial septal defect in utero for fetuses with hypoplastic left heart syndrome and intact or highly restrictive atrial septum.

BACKGROUND: Infants born with hypoplastic left heart syndrome and an intact or highly restrictive atrial septum face a neonatal mortality of at least 48% despite early postnatal left atrial decompression and palliative surgery. Prenatal left atrial decompression has been suggested as a means of improving these outcomes. This study reports the feasibility of fetal catheterization to create an interatrial communication and describes technical considerations. METHODS AND RESULTS: Seven fetuses at 26 to 34 weeks' gestation with hypoplastic left heart syndrome and intact or highly restrictive atrial septum underwent attempted prenatal intervention. Under ultrasound guidance, the atrial septum was approached with a needle introduced percutaneously from the maternal abdominal surface. In 6 of 7 fetuses, the atrial septum was successfully perforated, with balloon dilation of this iatrogenic defect resulting in a small but persistent interatrial communication. There were no maternal complications. One fetus died after the procedure. The remaining fetuses were liveborn at term, although 4 died as neonates. CONCLUSIONS: Ultrasound-guided fetal atrial septoplasty consisting of septal puncture and balloon dilation is feasible and can be performed percutaneously to minimize maternal risk. Although we have not demonstrated any positive clinical impact to date, it is our hope that further technical evolution will ultimately enable prenatal left atrial decompression and improvement of outcomes in fetuses with hypoplastic left heart syndrome and intact atrial septum.

Cardiac Catheterization↗
PubMed1979

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↗
PubMed1996

[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↗
PubMed1993

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↗