Atrial Septal Defects in the Adult

Assessment of right heart dilatation with magnetic resonance imaging and multidetector computed tomography angiography: spectrum of disease findings

Right heart chamber enlargement can be caused by a diverse and heterogeneous group of conditions with highly varied clinical symptoms and signs. An appreciation of the pathophysiology, causes, and imaging features of right heart enlargement is paramount in recognizing and potentially ameliorating the development of right heart dysfunction or adverse cardiac events. Chest x-ray and transthoracic echocardiography have traditionally been, and still are, the mainstay in initial evaluation of right heart dilatation; however, recent advances in both multidetector computed tomography and cardiovascular magnetic resonance imaging now permit a comprehensive assessment of the causes and consequences of right heart dilatation.

The right ventricle: biologic insights and response to disease: updated

Despite ample evidence that right ventricular function is a critical determinant of the clinical response to a spectrum of cardiovascular diseases, there has been only a limited analysis of the unique and distinguishing physiologic properties of the RV under normal circumstances and in response to pathologic insults. This knowledge deficit is increasingly acknowledged. This review highlights some of these features and underscores the fact that rational therapy in RV failure needs to acknowledge its unique physiology and ought to be chamber specific. That is proven therapies for LV dysfunction do not necessarily apply to the RV. The updated version of this review now acknowledges recent advances in the understanding of metabolic, inflammatory and gender-specific influences on the right ventricle.

Genome-wide association study of multiple congenital heart disease phenotypes identifies a susceptibility locus for atrial septal defect at chromosome 4p16

We carried out a genome-wide association study (GWAS) of congenital heart disease (CHD). Our discovery cohort comprised 1,995 CHD cases and 5,159 controls, and included patients from each of the three major clinical CHD categories (septal, obstructive and cyanotic defects). When all CHD phenotypes were considered together, no regions achieved genome-wide significant association. However, a region on chromosome 4p16, adjacent to the MSX1 and STX18 genes, was associated (P=9.5×10⁻⁷) with the risk of ostium secundum atrial septal defect (ASD) in the discovery cohort (N=340 cases), and this was replicated in a further 417 ASD cases and 2520 controls (replication P=5.0×10⁻⁵; OR in replication cohort 1.40 [95% CI 1.19-1.65]; combined P=2.6×10⁻¹⁰). Genotype accounted for ~9% of the population attributable risk of ASD.

Catheter ablation in children and young adults: is there an additional benefit from remote magnetic navigation?

Purpose

Although rare, children and young adults can suffer from significant cardiac arrhythmia, especially in the context of congenital malformations and after cardiac surgery.

Methods

A total of 62 patients (32 female, median age 20 years) underwent an invasive electrophysiology study between 2008–2011: half had normal cardiac anatomy, whereas the remaining patients had various types of congenital heart disease. All patients were treated using either conventional techniques (CVN) or remote magnetic navigation (RMN).

Results

Patients treated with the RMN system differed substantially from patients in the CVN group with respect to presence of congenital heart disease (67 % vs. 37 %), previous cardiac surgery (59 % vs. 20 %) or failed previous conventional ablation (22 % vs. 9 %), respectively. Although these more complex arrhythmias resulted in longer median procedure duration (180 vs. 130 min, p = 0.034), the median overall fluoroscopy exposure in the RMN group was significantly lower (4.1 vs. 5.2 min, p = 0.020). Clinical outcome was comparable in both groups without complications caused by the ablation.

Conclusions

Catheter ablation using remote magnetic navigation is safe and feasible in children and young adults and is especially valuable in patients with abnormal cardiac morphologies. RMN resulted in significantly lower radiation exposure compared with the conventional technique.

Transcatheter interatrial septal defect closure in a large cohort: midterm follow-up results

OBJECTIVES

We evaluated immediate and midterm results of transcatheter closure of atrial septal defects (ASDs) and patent foramen ovale (PFO) using various closure devices.

MATERIALS AND METHODS

The study included four hundred fourteen patients (one hundred eighty-two men, two hundred thirty-two women; mean age 39 ± 12.3 years; range 17-67 years) who underwent transcatheter closure of secundum ASD (n = 193) or PFO (n = 221). All the patients were evaluated by transthoracic echocardiography and transesophageal echocardiography before the procedure. Transcatheter closure was performed by using Amplatzer (n = 184), Occlutech Figulla (n = 209), or BioSTAR (n = 21) devices. Closure of ASDs was performed under general anesthesia with transesophageal echocardiography guidance, and closure of PFOs was performed under local anesthesia with transthoracic echocardiography guidance. Follow-up controls were at 1, 6, and 12 months and annually thereafter. The median follow-up periods of ASD and PFO patients were 43 and 30 months.

RESULTS

The mean device size was 19.3 ± 6.2 mm for ASD patients and 24.6 ± 2.6 mm for PFO patients. The mean procedural and fluoroscopy times were 22.3 ± 4.7 and 4.1 ± 1.9 minutes for ASD closure and 12.4 ± 3.2 and 3.1 ± 1.2 minutes for PFO closure, respectively. Procedural device embolization occurred in only two patients (0.48%). During follow-up, recurrent embolic events occurred in four patients (1.8%) after PFO closure, and no residual shunts were seen after ASD closure. Device thrombosis developed in two ASD patients during the procedure and in one PFO patient at 12th month of the follow-up (0.72%).

CONCLUSION

Transcatheter closure of PFOs and secundum-type ASDs using the Amplatzer, Occlutech Figulla, and BioSTAR devices is an efficacious and safe therapeutic option.

Heart rate variability in patients with atrial septal defect and healthy children

OBJECTIVE

Heart rate variability (HRV) measures are altered in various cardiac and non-cardiac situations in children. The autonomic nervous system is assumed to have a role in the pathophysiology of atrial septal defect (ASD). In this study, we evaluated the autonomic system by measuring HRV in children with ASD.

METHODS

Twenty-eight patients with ASD and 32 healthy children (mean ages: 6.6±2.1 years and 6.4±2.2 years, respectively) were enrolled in the study. Twenty-four-hour ambulatory electrocardiographic recordings were obtained and the seven time-domain (SDNN, SDANN, rMSSD, SD, SDNN index, PNN50, and mean RR) and four frequency-domain (VLF, LF, HF, and LF/HF ratio) indices of HRV were analyzed.

RESULTS

A significant decrease in calculated HRV variables was observed in children with ASD as compared to controls. The HRV alteration was found in both time-domain and frequency-domain parameters.

CONCLUSIONS

Our results indicate that HRV is decreased in children with ASD, which implies parasympathetic withdrawal and sympathetic predominance.

Right ventricular failure in congenital heart disease

Despite developments in surgical techniques and other interventions, right ventricular (RV) failure remains an important clinical problem in several congenital heart diseases (CHD). RV function is one of the most important predictors of mortality and morbidity in patients with CHD. RV failure is a progressive disorder that begins with myocardial injury or stress, neurohormonal activation, cytokine activation, altered gene expression, and ventricular remodeling. Pressure-overload RV failure caused by RV outflow tract obstruction after total correction of tetralogy of Fallot, pulmonary stenosis, atrial switch operation for transposition of the great arteries, congenitally corrected transposition of the great arteries, and systemic RV failure after the Fontan operation. Volume-overload RV failure may be caused by atrial septal defect, pulmonary regurgitation, or tricuspid regurgitation. Although the measurement of RV function is difficult because of many reasons, the right ventricle can be evaluated using both imaging and functional modalities. In clinical practice, echocardiography is the primary mode for the evaluation of RV structure and function. Cardiac magnetic resonance imaging is increasingly used for evaluating RV structure and function. A comprehensive evaluation of RV function may lead to early and optimal management of RV failure in patients with CHD.

MEDICAL IMAGING AND COMPUTER-AIDED FLOW ANALYSIS OF A HEART WITH ATRIAL SEPTAL DEFECT

Computer-aided magnetic resonance (MR) fluid motion tracking and cardiac vorticity quantification of the right atrial flow is implemented in this study to suggest a new method for the diagnosis of an atrial septal defect (ASD). MR signals of blood moving in a cardiac chamber can be represented as an image and vary in intensity at every consecutive cardiac phase. A method was devised to perform flow analysis using MR imaging without modification of scan mode or protocol that allows velocity encoding. A single vortex or multiple vortices may appear in the cardiac chamber. However, velocity fields in any flow scenario are normally unable to reveal information for a concise analysis; therefore, in addition to velocity maps, vorticity flow maps on which the velocity field is superimposed are presented. Through a case study, the difference in vortex strengths pre- and post-atrial septal occlusion can be examined, and the results can be verified using computational fluid dynamics. Based on this framework, the degree of vortical flow was assessed for the right atrium of a subject with atrial septal defect. A relationship can be established between right atrial vorticity and the ASD. As such, there is clear utility of the developed system in its potential as a prognostic and investigative tool for the quantitative assessment of cardiac abnormalities parallel to examining magnetic resonance images.

Home-made fenestrated amplatzer occluder for atrial septal defect and pulmonary arterial hypertension

We report the management of a patient with secundum atrial septal defect (ASD) and severe pulmonary hypertension. A 65-year-old male with recently diagnosed atrial septal defect was referred to our centre for decompensated right heart failure with rest and exercise induced dispnea and severe pulmonary hypertension. Right heart catheterization confirmed a mean pulmonary pressure of about 55 mmHg and a Qp/Qs of 2.7. An occlusion test with a compliant large balloon demonstrated partial fall of pulmonary arterial pressure. The implantation of a home-made fenestrated Amplatzer ASD Occluder (ASO) was planned in order to decrease left-to-right shunt and promote further decrease of pulmonary arterial pressure in the long-term. Thus, by means of mechanical intracardiac echocardiography study with a 9F 9 MHz UltraIce catheter (Boston Scientific Corp.), we selected a 34 mm ASO for implantation. Four millimeter fenestration was made inflating a 4 mm non-compliant coronary balloon throughout the waist of the ASO, which was successfully implanted under intracardiac echocardiography. After six months, a decrease of pulmonary arterial pressure to 24 mmHg and full compensated right heart failure was observed on transthoracic echocardiography and clinical examination. This case suggests that transcatheter closure with home-made fenestrated ASD in elderly patients with severe pulmonary hypertension is feasible.

Midterm results of percutaneous closure of very large atrial septal defects in children: role of multislice computed tomography

AIMS

The aim of this study was to assess the midterm results of percutaneous closure of very large atrial septal defects (ASD) in children with transthoracic echocardiography (TTE) and multislice computed tomography (MSCT).

METHODS AND RESULTS

Among 142 children who underwent percutaneous ASD closure with the AMPLATZER® Septal Occluder (ASO) (AGA Medical Corporation, Plymouth, MN, USA) during an eight year period, 51 patients with very large defects, were evaluated by TTE and MSCT after a period of at least two years following ASD closure. Median age at ASD closure was six years (range 4-10), with mean ASD size 20.9±2.9 mm. Median device size was 20 mm (range 15-26) and median device: septal length ratio 0.95 (range 0.8-1). Early complications included one transient complete atrioventricular block and one device embolisation. At a median follow-up of 55 months (range 25-92) all patients were clinically asymptomatic and had a normal ECG. TTE did not demonstrate device protrusion across the lumen of either the systemic or pulmonary veins. The mean device: septal length ratio had decreased from 0.96±0.05 to 0.8±0.02 (p<0.001). There was good correlation between the measure of atrial septum length by TTE and MSCT (r: 0.79, p<0.001). MSCT identified moderate dynamic device protrusion into the lumen of systemic or pulmonary veins in five patients and partial device malpositioning in two patients.

CONCLUSIONS

Occlusion of very large ASD in children can be performed with low complications rate. MSCT provides detailed information regarding the location of the device with respect to surrounding anatomic structures and reveals anomalies not evident by TTE.

Right ventricular performance in congenital heart disease: a physiologic and pathophysiologic perspective

Underappreciated is the fact that the right ventricle is often the primary determinant of long-term morbidity and mortality in patients with congenital heart disease. Right ventricular performance in these patients depends on a unique set of physiologic and pathophysiologic factors that are rarely considered in acquired heart disease. This article explores this unique physiology and pathophysiology in the hope that it will enhance understanding of a wide variety of congenital cardiac anomalies.

Congenital heart disease in pregnancy

Heart disease is a main cause of maternal mortality in the United States and the United Kingdom. Most deaths are from acquired conditions. However, due to the increased survival of children born with congenital heart disease (CHD) over the past 30 years, the population of adults with congenital heart disease in the U.S. now exceeds 1 million. Thus, there are now more adults with CHD than children with CHD. Many of these adult survivors of pediatric heart disease are of childbearing age and are considering pregnancy. This article reviews the literature concerning pregnancy and CHD.

Medical image diagnostics based on computer-aided flow analysis using magnetic resonance images

Most of the cardiac abnormalities have an implication on hemodynamics and affect cardiovascular health. Diagnostic imaging modalities such as computed tomography and magnetic resonance imaging provide excellent anatomical information on myocardial structures, but fail to show the cardiac flow and detect heart defects in vivo condition. The computerized technique for fluid motion estimation by pixel intensity tracking based on magnetic resonance signals represents a promising technique for functional assessment of cardiovascular disease, as it can provide functional information of the heart in addition to analysis of its anatomy. Cardiovascular flow characteristics can be measured in both normal controls and patients with cardiac abnormalities such as atrial septal defect, thus, enabling identification of the underlying causes of these flow phenomena. This review paper focuses on an overview of a flow analysis scheme based on computer-aided evaluation of magnetic resonance intensity images, in comparison with other commonly used medical imaging modalities. Details of the proposed technique are provided with validations being conducted at selected abnormal cardiovascular patients. It is expected that this new technique can potentially extend applications for characterizing cardiovascular defects and their hemodynamic behavior.

Percutaneous treatment of patients with heart diseases: selection, guidance and follow-up. A review

Aortic stenosis and mitral regurgitation, patent foramen ovale, interatrial septal defect, atrial fibrillation and perivalvular leak, are now amenable to percutaneous treatment. These percutaneous procedures require the use of Transthoracic (TTE), Transesophageal (TEE) and/or Intracardiac echocardiography (ICE). This paper provides an overview of the different percutaneous interventions, trying to provide a systematic and comprehensive approach for selection, guidance and follow-up of patients undergoing these procedures, illustrating the key role of 2D echocardiography.

The Right Heart in Congenital Heart Disease, Mechanisms and Recent Advances

In patients with congenital heart disease, the right heart may support the pulmonary or the systemic circulation. Several congenital heart diseases primarily affect the right heart including Tetralogy of Fallot, transposition of great arteries, septal defects leading to pulmonary vascular disease, Ebstein anomaly and arrhythmogenic right ventricular cardiomyopathy. In these patients, right ventricular dysfunction leads to considerable morbidity and mortality. In this paper, our objective is to review the mechanisms and management of right heart failure associated with congenital heart disease. We will outline pearls and pitfalls in the management of congenital heart disease affecting the right heart and highlight recent advances in the field.

An inferior sinus venosus interatrial communication associated with a secundum atrial septal defect, clinically presenting in an adult patient: autopsy report

Atrial septal defects (ASD) are the most common congenital cardiac lesion in adults, representing up to 40% of acyanotic shunt lesions in patients older than 40 years. Secundum ASD comprises defects in the area of the oval fossa, and may be associated with other types of interatrial communications. We present a case of a 25 year-old female patient who was asymptomatic until the age 22 when she started presenting exertion dyspnea and lower limbs edema, during her third pregnancy. The patient was admitted in the emergency department because of a febrile respiratory distress syndrome dying in less than 36 hours after her arrival. The autopsy examination revealed pneumonia and a secundum ASD, associated with a rare form of interatrial communication, the inferior sinus venosus defect, which is characterized by an anomalous connection of the right pulmonary veins to the inferior caval vein at its opening in the right atrial cavity, while retaining partially their connection to the left atrium. A dysplastic and thickened mitral valve was also present. Signs of pulmonary hypertension confirm the Eisenmenger syndrome in this adult patient.

Neurohormonal and cytokine fluctuations following transcatheter closure for an atrial septal defect

INTRODUCTION

Inflammation and neurohormonal activation are considered to be involved in the development of earlier and/or later complications in congenital heart disease patients, even after a successful repair of the lesion. It is not yet clarified what is the role of the therapeutic interventions in the occurrence of such a response and how it could be associated with possible postoperative complications.

AIM

We sought to assess the inflammatory and neurohormonal response to transcatheter closure of secundum type atrial septal defects (ASD) over a six-month follow-up period. We also evaluated the association between the respective markers and catheterization data as well as echocardiographic measurements.

METHODS

Plasma concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), N-terminal-proatrial natriuretic peptide (NT-proANP) and N-terminal-probrain natriuretic peptide (NT-proBNP) were assessed and echocardiographic measurements were performed in twenty-eight patients with atrial septal defect prior to, and at the first, second and sixth months post transcatheter closure. Thirty-three age-matched healthy volunteers were also enrolled.

RESULTS

IL-6 plasma levels, although higher preoperatively, [physical logarithm (ln) IL-6: 3.37±0.66 vs 2.92±0.44 pg/ml, p=0.015], reached control levels postoperatively, at the end of the third month, whereas TNF-α and IL-10 were not influenced by the procedure. NT-proANP levels were elevated preoperatively compared to the control group (ln NT-proANP 3.78±0.572 vs 3.48±0.30, p=0.031), with a further significant increase during the 1st month (ln NT-proANP 3.78±0.572 vs 4.2±0.42, p=0.006), following the pattern of the left atrial volume enlargement, and remained high even 6 months after the procedure .On the other hand, the initially normal concentrations of NT-proBNP, after a transient significant increase during the first month postoperatively (ln NT-proBNP 3.56±0.94 vs 4.58±0.91, p<0.0001) returned to the controls' levels at the end of the third month. Preoperative concentrations of NT-proANP positively correlated with NT-proBNP concentrations and pulmonary to systemic flow ratio (Qp/Qs).

CONCLUSIONS

Transcatheter closure could improve, on a mid- term basis, the inflammatory process but natriuretic peptides' secretion continues in parallel with left atrial volume increase. Further follow up is required to determine the long-term progress of the inflammatory and neurohormonal response to the procedure.

Interatrial shunt: diagnosis of patent foramen ovale and atrial septal defect with 64-row coronary computed tomography angiography

PURPOSE

The aim of this study was to investigate the frequency with which interatrial shunts are found during routine coronary computed tomography (CT) angiography and to describe imaging characterizations of patent foramen ovale (PFO), atrial septal defect (ASD), and atrial septal aneurysm (ASA).

MATERIALS AND METHODS

A total of 1081 adult patients were evaluated retrospectively for interatrial shunting; 77 were excluded from the study. CT diagnosis of PFO was defined as (1) a channel-like appearance of the interatrial septum (IAS) and (2) a contrast agent jet flow from the left atrium (LA) to the right atrium (RA). ASD was defined as (1) the IAS resembling a membrane with a hole and (2) a contrast jet flow between the two atria. ASA was identified by detecting a minimum 10-mm protrusion of the LA beyond the IAS into the RA.

RESULTS

Among 1004 patients, 86 patients (8.6%) were diagnosed to have PFO. Another 23 patients (2.3%) had a hole in the IAS and were diagnosed as having ASD: 21 with an ostium secundum-type ASD and 2 with the sinus venosus type. ASA accompanied ASD in three patients.

CONCLUSION

Electrocardiography-gated CT using the saline-chaser contrast injection technique that is routinely used for coronary arterial imaging can be used to detect interatrial shunts. The technique can also serve as a method for differentiating PFO, ASD, and ASA.

Percutaneous radiofrequency catheter ablation for atrial fibrillation prior to atrial septal defect closure

Percutaneous Radiofrequency Catheter Ablation. Patients with an atrial septal defect (ASD) commonly have atrial fibrillation (AF) and closure of the ASD rarely controls the arrhythmia. We report on the management of 4 patients with recurrent medically refractory AF in the setting of an unrepaired ASD who underwent percutaneous RFA prior to ASD closure. In 3 of the 4 patients AF was controlled after ablation without antiarrhythmic drug therapy and in the fourth patient AF was controlled with antiarrhythmic therapy after ASD closure. Based on these limited results it seems reasonable to consider RFA of medically refractory AF in patients prior to planned percutaneous ASD closure.

Atrial septal defects presenting initially in adulthood: patterns of clinical presentation in enugu, South-East Nigeria

This paper aimed to evaluate the patterns of clinical presentation of adults with atrial septal defects (ASDs) who were diagnosed from transthoracic echocardiographic examination at the echocardiographic laboratory of the University of Nigeria Teaching Hospital Ituku-Ozalla, Enugu, Nigeria, from February 2002 to June 2010. 2251 new echocardiogram scans, with additional 373 repeat scans, were done within the period. 32 adults had ASDs (1.3%), made up of 9 males and 23 females. Secundum ASD constituted 75% while dyspnoea on exertion was the commonest symptom. Congestive cardiac failure was the clinical syndrome most commonly encountered, and most patients presented in the third decade. This paper demonstrated that ASDs are common congenital heart diseases in adult Nigerians, and that they are important causes of congestive heart failure. All adults with congestive heart failure must be referred for echocardiography for early identification of causes like ASDs, which are often forgotten, before the development of irreversible changes in the lungs.

The right ventricle: biologic insights and response to disease

Despite ample evidence that right ventricular function is a critical determinant of the clinical response to a spectrum of cardiovascular diseases, there has been only a limited analysis of the unique and distinguishing physiologic properties of the RV under normal circumstances and in response to pathologic insults. This review highlights some of these features and underscores the fact that rational therapy in RV failure should acknowledge this physiology and ought to be chamber specific.

"Grown-up" congenital heart disease and sudden death in a medical examiner's population

Despite advances in the management of congenital heart disease (CHD), children with CHD who survive into adulthood are at increased risk of sudden death. Sudden death may also be the initial presentation of undiagnosed CHD in some adults. This retrospective descriptive study outlines the spectrum of CHD presenting as sudden death in adults in a medical examiner's population. Despite its rarity (0.2% of all cases investigated between 1991 and 2007), CHD remains an important cause of sudden cardiac death to be recognized at adult autopsy. Bicuspid aortic valve and anomalous coronary anomalies were the most common malformations, comprising 36.9% and 26.2% of cases, respectively. However, a wide spectrum of simple to complex malformations can be seen, with or without prior surgery, and over a wide age spectrum. Once solely a pediatric entity, CHD is now "grown-up" and will likely be diagnosed by forensic pathologists with increased frequency in the future.