Large Atrial Septal Aneurysm Associated with Secundum Atrial Septal Defect.

Large Atrial Septal Aneurysm Associated with Secundum Atrial Septal Defect Nino Isakadze, MD, MHS, Jana Lovell, MD, Edward P. Shapiro, MD, Chun W. Choi, MD, Marlene S. Williams, MD, and Monica Mukherjee, MD, MPH, Baltimore, Maryland INTRODUCTION Atrial septal aneurysm (ASA) is a congenital or acquired outpouching of the atrial septum. It is an incidental finding in 1% to 2.5% of the general population.1-3 Although the clinical significance of isolated ASA is not certain,4 it is frequently associated with the presence of other septal abnormalities, including patent foramen ovale (PFO) and atrial septal defect (ASD).4-6 When associated with atrial septal abnormalities, ASA is associated with an increased risk for arterial embolism4 and recurrent stroke.7 Although very large ASAs are exceedingly rare, further workup and management pathways are not well defined.8 Here, we describe an unusual case of a large symptomatic ASA associated with secundum ASD. CASE PRESENTATION A 25-year-old woman with antineutrophil cytoplasmic antibody vasculitis complicated by pulmonary hemorrhage and polyangiitis, gastritis, and essential hypertension presented with intermittent pleurisy and postural palpitations, worsened when lying on her left side. She noted that symptoms were reduced after biannual rituximab treatments but progressively worsened a few months afterward, and subjectively, her symptoms correlated with increasing inflammatory markers. Her physical examination was unremarkable. Initial evaluation performed at an outside hospital included transthoracic echocardiogram (TTE) demonstrating a large ASA (images not available) and cardiac computed tomography (CCT), which did not show vascular abnormalities, vasculitis, or obstructive coronary disease. Demonstration on CCTof the large ASA is shown in Figure 1, without evidence of interatrial shunting. The patient also underwent cardiovascular magnetic resonance imaging (CMR), which showed a mildly reduced left ventricular ejection fraction at 51% (reference range, 57%-77%).8 Additionally, there was no evidence of acute or chronic From the Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland (N.I., J.L., E.P.S., M.S.W., M.M.); and the Division of Cardiothoracic Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Maryland (C.W.C.). Keywords: Atrial septal defect, Secundum atrial septal defect, Atrial septal aneurysm, Echocardiography Conflicts of interest: The authors report no conflicts of interest relative to this document. Correspondence: Monica Mukherjee, MD, MPH, Division of Cardiology, Johns Hopkins University, 301 Mason Lord Drive, Suite 2400, Baltimore, MD 21224. (E-mail: ). Copyright 2022 by the American Society of Echocardiography. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/). 2468-6441 https://doi.org/10.1016/j.case.2022.02.003 myocarditis or pericarditis. Native T1 mapping values were mildly higher than the normal range, but the calculated extracellular volumeusing the modified Look-Locker inversion recovery technique was within the normal limits, suggesting no evidence of diffuse myocardial fibrosis. Normal T2 mapping values indicated no evidence of regional or global myocardial edema. On delayed enhancement imaging, there was no evidence of prior myocardial infarction or focal fibrosis. However, CMR also demonstrated a large ASA that was highly mobile and measured 2.6 cm at the orifice and 2.8 cm in length. No large interatrial shunt was observed. Given her episodic palpitations, she also underwent rhythm monitoring for 12 days, which did not show tachy- or bradyarrhythmias. Given these findings, the patient then presented for a second opinion for further evaluation, and given the history of large ASA, TTE was performed with agitated saline to further evaluate for the presence of PFO and/or ASD. The patient had normal right atrial size, normal right ventricular size and function, and an echocardiography-derived shunt fraction of 0.7, suggestive of right-to-left shunting. Further details of right heart measurements are shown in Table 1. TTE demonstrated large mobile ASA with minimal respirophasic variation, protruding into the right atrium and measuring 2.9 cm in length and 2.0 cm in diameter. The ASA remained fixed in a rightward orientation, suggesting that a right-to-left shunt would be less likely to be demonstrated. As such, agitated saline study was indeterminate, and although no interatrial shunting was visualized with injection of agitated saline, maneuvers such as Valsalva and similar physiologic maneuvers (e.g., abdominal thrust, cough, sniff) to alter interatrial gradients that may have improved the sensitivity of right-to-left shunt were not performed (Figure 2, Videos 1 and 2). The patient was subsequently referred to cardiothoracic surgery for further evaluation and consideration of surgical intervention because of concern that her persistent postural palpitations were due to her large ASA. Transesophageal echocardiography (TEE) was recommended to further define anatomy and evaluate for the presence of interatrial shunt and confirmed the presence of a large ASA protruding into the right atrium, measuring up to 2.5 cm in length and 2.0 cm in diameter (Video 3). The septal tissue was redundant with multiple fenestrations (Videos 3 and 4) and evidence of right-to-left shunting with injection of agitated saline, as shown in Video 5. No evidence of shunt was seen with application of color Doppler, but visualization may have been improved by lowering the Nyquist baseline velocities to #40 cm/sec. Three-dimensional and biplane imaging was also concerning for an ASD, as evidenced by the immobile tissue defect seen at the base of the ASA at the superior aspect of the interatrial septum (Video 4). Using a shared decision-making approach and careful discussions among the patient, cardiology, and cardiothoracic surgery, the patient opted to proceed with surgical resection of the large ASA. Intraoperative in vivo evaluation of the interatrial septum revealed a 187 188 Isakadze et al VIDEO HIGHLIGHTS CASE: Cardiovascular Imaging Case Reports June 2022 Table 1 Right heart chamber size and function Echocardiographic parameter Video 1: Two-dimensional transthoracic imaging of mobile ASA. Two-dimensional TTE, four-chamber apical view, showing a large (2.9 cm in length and 2.0 cm in diameter), highly mobile ASA protruding into the right atrium throughout the cardiac cycle. Video 2: Two-dimensional transthoracic imaging of mobile ASA with agitated saline. TTE, four-chamber apical view, showing the agitated saline study, without evidence of interatrial shunting. However, it is important to note that further physiologic maneuvers such as Valsalva were not performed, making the findings indeterminate rather than negative. Video 3: Three-dimensional transesophageal imaging (...truncated)