Assessment of atrial septal defect size with 3D-transesophageal echocardiography: comparison with balloon method

Assessment of atrial septal defects using 3-dimensional transthoracic echocardiography prior to percutaneous device closure: first report from Bangladesh

BACKGROUND

Secundum atrial septal defect (ASD) is treated following trans-catheter closure in alternative to surgical treatment. Per-intervention selection of device size with balloon occlusive diameter (BOD) often cause tearing or enlarging, causing arrhythmias and hypotension. We assessed the suitability of percutaneous device closure for ASD using 3-dimensional transthoracic echocardiography (3DTTE).

OBJECTIVES

This study was conducted to investigate if 3DTTE could be an alternative of balloon sizing for selection of device size in atrial septal defect device closure.

DESIGN

It was a cross-sectional comparative study.

METHODS

This study was conducted at the department of Pediatric Cardiology, Bangabandhu Sheikh Mujib Medical University for a period of 2 years. Thirty-three purposively selected secundum ASD patients suitable for device closure were included in the study. Ethical permission was taken from the Institutional Review Board and written consent was taken from each patient's guardian. In this study, 3DTTE derived ASD diameter and BOD were compared with that of deployed device size using correlation analysis.

RESULTS

Out of 33 patients, 63.6% were female and 36.4% were males had a mean age of 18.07 ± 14.58 years (range 2-55 years). Mean diameter of ASD measured by 2-dimensional (2D) and 3-dimensional (3D) echocardiography were 17.09 ± 6.08 mm and 21.30 ± 6.56 mm, respectively, yielding a significant difference (p < 0.001). 3D echocardiography derived ASDs diameter were highly correlated with device size than BOD and 2D echocardiography derived diameter (2D echocardiography: r = 0.796, p = <0.001, 3D echocardiography: r = 0.960, p = <0.001, BOD: r = 0.840, p = <0.001).

CONCLUSION

3DTTE can accurately measure ASD diameter and can be used as an alternate, effective, and safe method to select device size.

Intracardiac Echocardiogram: Feasibility, Efficacy, and Safety for Guidance of Transcatheter Multiple Atrial Septal Defects Closure

We aimed to determine the feasibility, efficacy, success, and safety of intracardiac echocardiography (ICE) in transcatheter multiple atrial septal defect (ASD) closure. Of 185 patients with multiple ASDs who underwent transcatheter closure, 140 (76%) patients who weighed <30kg with a narrow distance between defects or in whom single device closure was anticipated were guided by ICE and 45 patients were guided by three-dimensional (3D) transesophageal echocardiography (TEE) with or without ICE. Patients in the ICE group were relatively younger and weighed less than those in the 3D TEE group (p < 0.0001). The ratio of the distance between defects >7 mm was high, and more cases required ≥2 devices in the 3D TEE group than those in the ICE group (p < 0.0001). All patients in the 3D TEE group and seven patients (5%) in the ICE group were operated on under general anesthesia (p < 0.0001). The fluoroscopic time was shorter in the ICE group (13.98 ± 6.24 min vs. 24.86 ± 16.47 min, p = 0.0005). No difference in the complete closure rate and complications was observed. ICE-guided transcatheter and 3D TEE were feasible, safe, and effective in successful multiple ASD device closures, especially for young children and patients at high risk under general anesthesia.

3D Echocardiography for Rheumatic Heart Disease Analysis: Ready for Prime Time

Rheumatic heart disease (RHD) remains to be a very important health issue worldwide, mainly in underdeveloped countries. It continues to be a leading cause of morbidity and mortality throughout developing countries. RHD is a delayed non-suppurative immunologically mediated inflammatory response to the throat infection caused by a hemolytic streptococcus from the A group (Streptococcus pyogenes). RHD keeps position 1 as the most common cardiovascular disease in young people aged <25 years considering all the continents. The disease can lead to valvular cardiac lesions as well as to carditis. Rheumatic fever valvular injuries lead most commonly to the fusion and thickening of the edges of the cusps and to the fusion, thickening, and shortening of the chordae and ultimately to calcification of the valves. Valvular commissures can also be deeply compromised, leading to severe stenosis. Atrial and ventricular remodeling is also common following rheumatic infection. Mixed valvular lesions are more common than isolated valvular disorders. Echocardiography is the most relevant imaging technique not only to provide diagnostic information but also to enable prognostic data. Further, it presents a very important role for the correction of complications after surgical repair of rheumatic heart valvulopathies. Three-dimensional (3D) echocardiography provides additional anatomical and morphofunctional information of utmost importance for patients presenting rheumatic valvopathies. Accordingly, three-dimensional echocardiography is ready for routine use in patients with RHD presenting with valvular abnormalities.

How to Size ASDs for Percutaneous Closure

Percutaneous closure is the treatment of choice for secundum-type atrial septal defects (ASD). Balloon sizing (BS) has been the method of choice for deciding on device size. Improved 2D- and 3D-transesophageal echocardiographic (TEE) imaging challenged the necessity of BS. Balloon sizing was performed with two additional techniques to measure the stretched dimension of the ASD. The 1st method uses a stiff guide wire which stretches the ASD and 2D TEE. The second technique uses 3D TEE. Two hundred and thirty-six patients with minimum 1-year follow-up were enrolled. The population was classified into three groups: BS (group 1) n = 90, 2D-TEE (group 2) n = 87, and 3D-TEE (group 3) n = 59. All groups showed a distinct correlation between the maximum baseline dimensions and the device size (R = 0.821). The relative expansion rate did not differ between BS and 3D-TEE. Group 2 (2D-TEE) showed a significantly lower expansion rate. Procedural success and complications did not differ statistically between the 3 groups. 2D TEE sizing was the simplest method without loss of accuracy. 3D sizing offers the advantage of accurate and fast shape assessment, but resulted in more undersizing. Accurate sizing of ASDs with a floppy septum remains a challenge.

Three-dimensional Echocardiography in Congenital Heart Disease: An Expert Consensus Document from the European Association of Cardiovascular Imaging and the American Society of Echocardiography

Three-dimensional echocardiography (3DE) has become important in the management of patients with congenital heart disease (CHD), particularly with pre-surgical planning, guidance of catheter intervention, and functional assessment of the heart. 3DE is increasingly used in children because of good acoustic windows and the non-invasive nature of the technique. The aim of this paper is to provide a review of the optimal application of 3DE in CHD including technical considerations, image orientation, application to different lesions, procedural guidance, and functional assessment.

The relation between atrial septal defect shape, diameter, and area using three-dimensional transoesophageal echocardiography and balloon sizing during percutaneous closure in children

BACKGROUND

A trans-catheter closure of an atrial septal defect (ASD) is efficient. Balloon sizing (BS) during the catheterization leads to an overestimation of ASD size. Three-dimensional transoesophageal echocardiography (3D-TEE) allows the ASD morphology to be assessed comprehensively. The aim of this study was to assess the relationships between the shape and the measurements of ASDs by 2D-, 3D-TEE, and BS in children.

METHODS AND RESULTS

Thirty children who underwent percutaneous closures of a single ASD were enrolled. ASD diameters were measured by 2D-transthoracic echocardiography (TTE), 2D-TEE, 3D-TEE and compared with BS. The ASD area was measured on 3D-TEE images after multi-planar reconstruction. ASD was estimated as round or oval on 3D-TEE 'en-face' view. 2D-TTE, 2D-TEE, and 3D-TEE(max) ASD diameters were well correlated with BS (r = 0.75; 0.80, and 0.85, respectively). Mean diameters were all significantly smaller than the mean BS. The mean difference between the balloon area and 3D-TEE area was 1.6 ± 1.4 cm(2) (P < 0.0001). The mean difference between BS and 3D-TEE(max) diameters was higher in round ASDs than in oval ASDs (4.0 ± 3.3 vs. 1.1 ± 3.3, P = 0.02). With multivariate linear regression analysis, two formulas were built to predict BS. The first model was BS = 1.07 × 3D-TEE(max)- 3.1 × ASDshape + 3. The ASD shape was 0 for round and 1 for oval ASDs. A second model was BS = 4.5 × ASDarea + 11.5.

CONCLUSION

The ASD shape is accurately estimated by 3D-TEE and influences the relationship between echocardiographic measurements and BS. The ASD shape, its maximal diameter and the area assessed by 3D-TEE may be sufficient to determine the device size without BS in children.

The Role of Catheter-Based and Surgical Treatments in Patients With Congenital Heart Disease and Pulmonary Hypertension

This manuscript is intended to provide a brief overview of the indications for and outcomes of surgical and transcatheter interventions for congenital heart disease and pulmonary hypertension (PH). Pulmonary hypertension is frequently encountered in children and adults with congenital heart disease and is most commonly related to large “central” shunts, ie, those occurring at the ventricular or great arterial level (Figure 1). If uncorrected early in infancy or childhood, large central shunts result in increased pulmonary blood flow, left heart volume overload, PH, and heart failure. If the child survives this initial period of volume overload and heart failure, they will very likely develop effacement of the normal pulmonary arterial architecture and severe elevations in pulmonary arterial resistance, eventually resulting in cyanosis and Eisenmenger syndrome.1

A comparison between size of the occluder device and two-dimensional transoesophageal echocardiographic sizing of the ostium secundum atrial septal defect

Objectives

Transcatheter closure of a secundum atrial septal defect (ASD II) has become an effective alternative for surgical treatment. In this study we evaluated the correlation between the two-dimensional transoesophageal echocardiographic (2D TEE) sizing of ASDs and the actual diameter of occluders in patients undergoing device closure.

Methods

The records of 54 patients who underwent transcatheter ASD closure were reviewed. ASD characteristics and maximum defect diameter were evaluated using preprocedure 2D TEE images. Appropriate device size was determined by the balloon sizing method, which measures the balloon occlusive diameter (BOD) via TEE and fluoroscopy. ASD closure was performed under continuous TEE monitoring using the Amplatzer occluder in all patients.

Results

The mean of the TEE-derived maximum defect diameter was significantly lower than the mean of the BOD (17.8 ± 4.5 vs 22.1 ± 5.1 mm; p < 0.001) and the mean size of the implanted occluder device (17.8 ± 4.5 vs 23.3 ± 5.1 mm; p < 0.001). However, a good correlation was found between the TEE-derived defect size and the BOD (BOD = 0.898 × TEE defect size + 6.212, R = 0.824; p < 0.001) and between the TEE measurement and the final size of the implanted Amplatzer (device size = 0.928 × TEE defect size + 6.853, R = 0.822; p < 0.001).

Conclusions

2D TEE may provide a good equation to predict the BOD or the size of the occluder device; however, further studies are needed to investigate whether it is feasible to perform transcatheter ASD occlusion without balloon sizing.

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.

Trans-catheter closure of atrial septal defect: Balloon sizing or no Balloon sizing - single centre experience

BACKGROUND

Selecting the device size using a sizing balloon could oversize the ostium secundum atrial septal defect (OSASD) with floppy margins and at times may lead to complications. Identifying the firm margins using trans-esophageal echocardiography (TEE) and selecting appropriate-sized device optimizes ASD device closure. This retrospective study was undertaken to document the safety and feasibility of device closure without balloon sizing the defect.

METHODS

Sixty-one consecutive patients who underwent trans-catheter closure of OSASD guided by balloon sizing of the defect and intra procedural fluoroscopy (group I) and 67 consecutive patients in whom TEE was used for defect sizing and as intraprocedural imaging during device deployment (group II) were compared. The procedural success rate, device characteristics, and complications were compared between the two groups.

RESULTS

The procedure was successful in 79.7 % patients. The success rate in group II (60 of 67, 89.6%) was significantly higher than in group I (41 of 61, 67.2 %) (P = 0.002). Mean upsizing of ASD device was significantly lower in group II (P < 0.001). TEE also provided better success rate with smaller device in subjects with large ASD (>25 mm) and in those who were younger than 14 years of age. There were four cases of device embolization (two in each group); of which one died in group II despite successful surgical retrieval.

CONCLUSION

Balloon sizing may not be essential for successful ASD device closure. TEE-guided sizing of ASD and device deployment provides better success rate with relatively smaller sized device.

Cardiac flow component analysis

In a chamber of the heart, large-scale vortices are shown to exist as the result of the dynamic blood flow and unique morphological changes of the chamber wall. As the cardiovascular flow varies over a cardiac cycle, there is a need for a robust quantification method to analyze its vorticity and circulation. We attempt to measure vortex characteristics by means of two-dimensional vorticity maps and vortex circulation. First, we develop vortex component analysis by segmenting the vortices using an data clustering algorithm before histograms of their vorticity distribution are generated. The next stage is to generate the statistics of the vorticity maps for each phase of the cardiac cycle to allow analysis of the flow. This is followed by evaluating the circulation of each segmented vortex. The proposed approach is dedicated to examining vortices within the human heart chamber. The vorticity field can indicate the strength and number of large-scale vortices in the chamber. We provide the results of the flow analysis after vorticity map segmentation and the statistical properties that characterize the vorticity components. The success of the cardiac measurement and analysis is illustrated by a case study of the right atrium. Our investigation shows that it is possible to utilize a data clustering algorithm to segment vortices after vorticity mapping, and that the vorticity and circulation analysis of a chamber vorticity can provide new insights into the blood flow within the cardiovascular structure.

A comparison of echocardiographic modalities to guide structural heart disease interventions

Percutaneous techniques to treat structural heart disease are rapidly evolving based on innovative interventions and the considerable advancement in image guidance technology. While two-dimensional transthoracic and transesophageal echocardiography have been integral to procedural planning and execution, intracardiac and three-dimensional echocardiography supply unique visualization of target structures with a potential improvement in patient safety and procedural efficacy. The choice of image guidance modality is based on specific differences between imaging systems, as well as other variables including cost, patient safety, operator expertise, and complexity of procedure. We will compare the adjunctive imaging tools for structural heart disease interventions, with a focus on intracardiac echocardiography and real-time three-dimensional transesophageal echocardiography.

Assessment of atrial septum morphology by live three-dimensional echocardiography

To evaluate the morphology of atrial septum by the live three-dimensional echocardiography (L3DE) and its value of clinical application, L3DE was performed in 62 subjects to observe the morphological characteristics and dynamic change of the overall anatomic structure of atrial septum. The study examined 49 patients with atrial septal defect (ASD), including 3 patients with atrial septal aneurysm, and 10 healthy subjects. ASD in the 35 patients was surgically confirmed. The maximal diameters of ASD were measured and the percentages of area change were calculated. The parameters derived from L3DE were compared with intraoperative measurements. The results showed that L3DE could directly and clearly display the morphological features of overall anatomic structure of normal atrial septum, repaired and artificially-occluded atrial septum, atrial septal aneurysm. The defect area in ASD patients changed significantly during cardiac cycle, which reached a maximum at end-systole and a minimum at end-diastole, with a mean change percentage of 46.6%, ranging from 14.8% to 73.4%. The sizes obtained from L3DE bore an excellent correlation with intraoperative findings (r=0.90). It is concluded that L3DE can clearly display the overall morphological features and dynamic change of atrial septum and measure the size of ASD area accurately, which is important in the decision to choose therapeutic protocols.

Blood Flow Imaging?A New Angle-Independent Ultrasound Modality for the Visualization of Flow in Atrial Septal Defects in Children

BACKGROUND

Color Doppler imaging (CDI) is the most applied method for evaluation of flow in atrial septal defects (ASD). A new real time ultrasound flow imaging modality called blood flow imaging (BFI) is able to visualize the blood flow in any direction of the image and is not limited by velocity aliasing. The method thereby overcomes the two limitations most often encountered in CDI. In this study we compared BFI with CDI for the visualization of interatrial blood flow in children.

METHODS

We studied ASD flow in 13 children using both CDI and BFI in the same examination. CDI and BFI cineloops were prepared off-line and both optimal and suboptimal (increased color artifacts) images were presented in random order to four observers. They were asked to range from 0-100 on a visual analogue scale how certain they were of interatrial blood flow. The CDI and BFI ratings were compared using the exact Wilcoxon signed rank test for paired samples.

RESULTS

All ASDs visualized with CDI were confirmed using BFI. Two of the observers ranked BFI as being significantly better than CDI when the images were optimized. When the images were suboptimal three of the observers rated BFI as being significantly better.

CONCLUSIONS

This pilot study indicates that BFI improves the visualization of interatrial blood flow in children. To include BFI in the ordinary echocardiography examination is easy and not time consuming. The method may prove to be a useful supplement to CDI in ASD imaging.

Live 3D Echocardiography with the Pediatric Matrix Probe

Three-dimensional echocardiography (3DE) enables new views of heart valves and the septa to be imaged. While the previous 3DE system was cumbersome, the recent introduction of live 3DE allowed for routine use of the technique in adult patients. Here, we report our initial experiences in adapting live 3DE and the adult matrix probe to the pediatric population. Thirty-four 3DE examinations were performed on children, aged 1 day to 12 years (n = 23; median 4 years) and fetuses 20-33 weeks in gestation (n = 11; median 25 weeks), many of whom had various congenital heart diseases. The pediatric matrix probe (2-7 MHz) was used for 2D, Doppler, and 3DE. New modalities of the Vision 2007 (Philips) were applied: live, full volume, thick slice, 3D color Doppler, the QLAB system for navigation, and cropping. The pediatric matrix probe allows for complete 2D and 3D echocardiography, and new acoustic windows are now available to perform live 3DE. The higher frequency of the probe increases the 3D image resolution obtained in neonates and fetuses. This advancement allows new views of the aorta, pulmonary valve, septa and intra cardiac anatomy to be captured. Real time 3DE is a feasible method in addition to conventional 2D echocardiography for evaluating congenital heart disease.

Actualización en técnicas de imagen cardiaca. Ecocardiografía, resonancia magnética en cardiología y tomografía computarizada con multidetectores

This article contains a review of the most significant publications on non-invasive recent cardiac imaging techniques in 2005. The increasing importance of technological innovation in echocardiography is reflected in the sections on three dimensional echocardiography, contrast echocardiography, and myocardial deformation measurement techniques (i.e., strain echocardiography). The most important developments affecting cardiology in the techniques of magnetic resonance imaging and multidetector computed tomography are also summarized. This review ends with a detailed description of the contributions made by imaging techniques to the diagnosis of aortic disease.