A 61-year-old man was diagnosed by transthoracic echocardiography with a primum atrial septal defect (ASD) and mild-to-moderate mitral regurgitation (MR) because of an anterior mitral leaflet prolapse. He was, therefore, scheduled for surgical repair of the ASD and mitral valve (MV). Written informed consent was obtained from the patient for publication of this case report and any accompanying images.
Intraoperative transesophageal echocardiography was performed using a 3D echocardiographic matrix-array probe (X7-2t Transducer; Philips Healthcare, Andover, MA). First, 2D echocardiographic analysis in the midesophageal 4-chamber (ME 4ch) view demonstrated a primum ASD with right ventricular dilation and 3 MR jets (Fig. 1; Video 1, Supplemental Digital Content 1, http://links.lww.com/AA/B204). The modified ME bicaval view with rightward turn revealed a dynamically changing defect during the cardiac cycle, with mild tricuspid regurgitation (Video 2, Supplemental Digital Content 2, http://links.lww.com/AA/B205). Next, using systematic 3D echocardiographic examination of the ASD,1,2 3D full-volume images were acquired for further morphological evaluations. After optimizing an ME 4ch view of the interatrial septum and atrioventricular valves at 0° in the 2D mode, a 3D echocardiographic view was obtained with a 7-beat gated full-volume mode. The obtained image was manipulated to demonstrate atrioventricular valves from a biatrial perspective and en face views of the ASD from the left atrial (LA) perspective (Fig. 2). An isolated MV cleft extending toward the septum was revealed and differentiated from the tricuspid valve leaflets in en face views of the atrioventricular valves from the atrial side. Although a tricuspid septal leaflet cleft can coexist and cause tricuspid regurgitation, this did not seem to be the case in our patient (first part of Video 3, Supplemental Digital Content 3, http://links.lww.com/AA/B206). In addition, dynamic changes in the defect over the cardiac cycle were demonstrated using en face views of the defect from the LA perspective (second part of Video 3, Supplemental Digital Content 3, http://links.lww.com/AA/B206). Next, the defect sizes during the cardiac cycle were quantified using the LA view in Figure 2C (Fig. 3). The surface area of the defect varied significantly, with a maximal size in late ventricular diastole (atrial contraction, Fig. 3A) and a minimal size in late ventricular systole (atrial relaxation, Fig. 3B). The major axis of the oval-shaped defect changed its configuration during the cardiac cycle (red line in Fig. 3, A and B). Major and minor lengths, and defect areas in late ventricular diastole and systole, measured with multiplanar reconstruction (MPR) of 3D quantification software (Philips Medical Systems, Andover, MA) as previously described,3 are demonstrated in Figure 3, C and D, respectively.
During surgery, the defect was closed with a single autologous pericardial patch and the MV cleft was sutured. No residual shunt and only trivial MR were revealed with 2D color flow Doppler analysis. The patient was successfully weaned off cardiopulmonary bypass, and he recovered with an uneventful postoperative course.
Two-dimensional echocardiographic imaging of ASDs is based on a limited number of orthogonal planes through the heart from predefined transducer positions, whereas 3D echocardiography not only allows en face views of the entire interatrial septum and surrounding tissues during the cardiac cycle but also enables acquisition of an infinite number of different planes from a 3D data set. These enable accurate determination of the ASD location, size, and association with surrounding tissues3–5 and can have implications in patient selection and appropriate guidance for transcatheter ASD closure.3,5,6
The surface area of the ASD generally changes dynamically during the cardiac cycle. As seen with 3D echocardiography, both atrial filling during relaxation and emptying during contraction significantly change the surface area of secundum ASDs during the cardiac cycle, with a maximal size in atrial filling and a minimal size in atrial contraction.4,6 Other types of ASDs, including sinus venosus and primum ASDs, have also been reported to exhibit significant dynamic changes in the same manner over the cardiac cycle.7
However, in this case, the change was the exact opposite motion to that previously described (Fig. 3). The configuration of the axes of the ASD also changed over the cardiac cycle, rotating clockwise from the LA view (red lines in Fig. 3, A and B), seemingly being pulled down by the left ventricular basal inferior wall. Quantitative measurements with MPR demonstrated a maximal size in late ventricular diastole (atrial contraction) and a minimal size in late ventricular systole (atrial relaxation) (Fig. 3, C and D). This seems to suggest that the orifice size of a primum ASD immediately above the annulus of the atrioventricular valve or of a defect located adjacent to the interventricular septum, including the spectrum of endocardial cushion defects, is affected by the annular circumferential and longitudinal motion during each cardiac cycle. In Figure 3C, which is a 2ch view of the atrium, the red line in the diastolic phase is the ideal scan line for visualization of the maximal diameter with 2D analysis. However, it is difficult to assess these motions and precisely scan on the line while adjusting for the cardiac phase using 2D echocardiography, as shown in Video 2 (Supplemental Digital Content 2, http://links.lww.com/AA/B205), because it is virtually impossible to know where a 2D plane cuts, given the lack of references. Although the X-plane mode can simultaneously scan 2 orthogonal planes (similar to the combination in the first part of Videos 1 and 2, Supplemental Digital Contents 1 and 2, http://links.lww.com/AA/B204 and http://links.lww.com/AA/B205) and help understand the dynamic motion of the defect, it cannot identify the entire shape of the defect and its detailed motion during the cardiac cycle and cannot always scan along the ideal line of the minimal and maximal diameters over the entire cardiac cycle. However, changes in the ASD orifice did not seem to greatly affect the flow profile through the defect because CFD analysis demonstrated continuous steady flow over the entire cardiac cycle.
A primum ASD and associated surrounding structures, including atrioventricular valves, are generally observed in the ME 4ch view.8 Information on the location of the defect leads to appropriate diagnosis of the type of ASD, although the size of the defect cannot always be precisely measured. In this case, 2D analysis of the primum defect with the ME 4ch view and the orthogonal plane to that (posterior to anterior scanning) enabled approximate measurement of the minor and major axes of the defect and detection of changes in the defect during the cardiac cycle, respectively. However, these might have been overestimated in comparison with those of 3D measurements because the scan lines were probably oblique to the ideal lines in Figure 3A and 3B. In addition, inferior to superior scanning, obtained by advancing and anteflexing the probe (corresponding to the 2ch view of the atrium in Fig. 3), would not have been able to precisely detect these lines.
A multibeat gated full-volume mode of 3D analysis facilitates evaluation of orifice changes because the frame rate remains relatively higher (52 Hz) than that with a single beat 3D zoom mode. However, the orifice changes would be related, at least theoretically, to the atrioventricular base motion, while also being associated with the accompanying anterior mitral leaflet cleft and/or the degree of MR. These, along with the known caveat that the 3D structures are imaged and measured on a flat level plane in any of the figures, including those with MPR, could also be the potential reasons for these apparent reversed orifice changes.
Changes in the size and axis of the defect over the cardiac cycle need to be considered for precise measurement of a primum ASD. Knowledge of these features may be useful during closure of primum ASDs using transcatheter devices, although this is only occasionally performed and often not feasible because of the proximity of the atrioventricular valves.8 En face views of the defect on 3D echocardiography might be helpful in assessing these characteristics.
Clinician’s Key Teaching Points
By Nikolaos J. Skubas, MD, Massimiliano Meineri, MD, and Martin J. London, MD
- The type, location, and size of an atrial septal defect (ASD) and its association with neighboring structures are important characteristics for the echocardiographer to determine because they may be used to guide treatment.
- A secundum ASD is larger during atrial filling (ventricular systole). It is usually located in the middle of the interatrial septum and away from the atrioventricular valves. It is commonly treated with a transcatheter closure device of suitable size. A primum ASD is in close proximity to the atrioventricular valves, and surgical closure is usually preferred. Two-dimensional transesophageal echocardiographic imaging in a basal midesophageal echocardiography 4-chamber view, even with simultaneous orthogonal imaging in a midesophageal bicaval view, may not always transect an ASD along its largest dimensions or image the neighboring anatomic structures.
- In this case of a patient undergoing surgical closure of a primum ASD, full-volume 3D transesophageal echocardiography with color flow Doppler was used to image the defect en face from the left atrial perspective. The orifice of the defect was larger during atrial contraction (ventricular diastole). An anterior mitral leaflet cleft was identified and repaired as well.
- The close proximity of a primum ASD to the atrioventricular valves is a relative contraindication for a transcatheter device closure. The cyclic changes of its orifice, due in part to tethering forces from the adjoining basal ventricular segments, are more easily interrogated with 3D echocardiography, which enables en face display of the entire defect and multiple cutting planes across the defect. When assessing an ASD, definition of its geometry, appreciation of the dynamic change, and precise measurement of its size are critical for choosing the type of procedure and selecting an appropriate closure device.
Name: Masataka Kuroda, MD, PhD.
Contribution: This author helped design the study, conduct the study, collect the data, analyze the data, and prepare the manuscript.
Attestation: Masataka Kuroda approved the final manuscript.
Name: Minami Kumakura, MD.
Contribution: This author helped prepare the manuscript.
Attestation: Minami Kumakura approved the final manuscript.
Name: Tomonobu Sato, MD.
Contribution: This author helped prepare the manuscript.
Attestation: Tomonobu Sato approved the final manuscript.
Name: Shigeru Saito, MD, PhD.
Contribution: This author helped prepare the manuscript.
Attestation: Shigeru Saito approved the final manuscript.
This manuscript was handled by: Martin J. London, MD.
1. Lang RM, Badano LP, Tsang W, Adams DH, Agricola E, Buck T, Faletra FF, Franke A, Hung J, de Isla LP, Kamp O, Kasprzak JD, Lancellotti P, Marwick TH, McCulloch ML, Monaghan MJ, Nihoyannopoulos P, Pandian NG, Pellikka PA, Pepi M, Roberson DA, Shernan SK, Shirali GS, Sugeng L, Ten Cate FJ, Vannan MA, Zamorano JL, Zoghbi WAAmerican Society of Echocardiography; European Association of Echocardiography. American Society of Echocardiography; European Association of Echocardiography. . EAE/ASE recommendations for image acquisition and display using three-dimensional echocardiography. J Am Soc Echocardiogr. 2012;25:3–46
2. Saric M, Perk G, Purgess JR, Kronzon I. Imaging atrial septal defects by real-time three-dimensional transesophageal echocardiography: step-by-step approach. J Am Soc Echocardiogr. 2010;23:1128–35
3. Taniguchi M, Akagi T, Watanabe N, Okamoto Y, Nakagawa K, Kijima Y, Toh N, Ohtsuki S, Kusano K, Sano S. Application of real-time three-dimensional transesophageal echocardiography using a matrix array probe for transcatheter closure of atrial septal defect. J Am Soc Echocardiogr. 2009;22:1114–20
4. Franke A, Kühl HP, Rulands D, Jansen C, Erena C, Grabitz RG, Däbritz S, Messmer BJ, Flachskampf FA, Hanrath P. Quantitative analysis of the morphology of secundum-type atrial septal defects and their dynamic change using transesophageal three-dimensional echocardiography. Circulation. 1997;96:II–323–7
5. Vegas A, Meineri M. Core review: three-dimensional transesophageal echocardiography is a major advance for intraoperative clinical management of patients undergoing cardiac surgery: a core review. Anesth Analg. 2010;110:1548–73
6. Acar P, Saliba Z, Bonhoeffer P, Aggoun Y, Bonnet D, Sidi D, Kachaner J. Influence of atrial septal defect anatomy in patient selection and assessment of closure with the Cardioseal device; a three-dimensional transoesophageal echocardiographic reconstruction. Eur Heart J. 2000;21:573–81
7. Roberson DA, Cui W, Patel D, Tsang W, Sugeng L, Weinert L, Bharati S, Lang RM. Three-dimensional transesophageal echocardiography of atrial septal defect: a qualitative and quantitative anatomic study. J Am Soc Echocardiogr. 2011;24:600–10
8. Burch TM, Mizuguchi KA, DiNardo JA. Echocardiographic assessment of atrial septal defects. Anesth Analg. 2012;115:772–5