Impending Interventricular Septal Rupture After CABG: Conservative Management of a Post-Infarction Septal Pseudoaneurysm

Impending Interventricular Septal Rupture After CABG: Conservative Management of a Post-Infarction Septal Pseudoaneurysm | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Impending Interventricular Septal Rupture After CABG: Conservative Management of a Post-Infarction Septal Pseudoaneurysm Alessandro Ricasoli, Laura Asta, Salvatore Scandura, Umberto Benedetto, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8950917/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Background : Ventricular septal defect is a rare yet life-threatening mechanical complication of myocardial infarction. In exceptionally uncommon cases, the interventricular septum undergoes localized dissection with formation of an intraseptal pseudoaneurysm without complete septal rupture. While most pseudoaneurysms develop in the acute post-infarction phase, delayed presentation following surgical revascularization is exceedingly rare. Case Summary : We report the case of a 61-year-old man who underwent surgical coronary artery bypass grafting after myocardial infarction. Early postoperative transesophageal echocardiography identified a 3 × 3 cm mid-septal pseudoaneurysm without communication between the two ventricular chambers. Given the patient’s hemodynamic stability, a conservative strategy with combined anticoagulation and antiplatelet therapy was adopted. Serial transesophageal echocardiographic follow-up demonstrated progressive spontaneous thrombosis and complete closure of the pseudoaneurysm. At six months, the patient remained asymptomatic with preserved left ventricular function. Discussion : Post-CABG interventricular septal pseudoaneurysm is an exceptionally rare finding. In carefully selected hemodynamically stable patients, conservative management may represent a reasonable alternative to surgery, as spontaneous thrombosis and resolution can occur. Close echocardiographic surveillance is essential to guide therapeutic decisions and promptly detect complications. Conclusion : This case highlights that early diagnosis and individualized management of post-CABG interventricular septal pseudoaneurysm may lead to favorable outcomes without surgical intervention in selected stable patients. Ventricular septal defect Myocardial Infarction Pseudoaneurysm Interventricular Septum Figures Figure 1 Introduction Post-infarction ventricular septal defect (VSD) is an uncommon but life-threatening mechanical complication that typically develops within the first 2–7 days after myocardial infarction. In the contemporary percutaneous coronary intervention (PCI) era, the incidence of mechanical complications remains low—approximately 0.27% in STEMI and 0.06% in NSTEMI patients—without significant temporal variation [1]. Unlike true VSDs, ventricular pseudoaneurysms (PSAs) are contained by pericardium or fibrotic tissue, which limits free rupture and prevents uncontrolled blood extravasation beyond the ventricular cavity [2]. Although most PSAs occur in the acute post-infarction setting, delayed septal complications have also been reported after myocardial revascularization procedures [3]. Herein, we describe a case of an early postoperative interventricular septal pseudoaneurysm developing after coronary artery bypass grafting (CABG), initially mimicking an impending septal defect. We discuss the diagnostic challenges, therapeutic strategy, and clinical outcome, emphasizing the role of multimodality imaging and individualized management. Case Presentation A 61-year-old Caucasian male with a history of hypertension, type 2 diabetes mellitus, and obesity presented with anterior ST-segment elevation myocardial infarction (STEMI). Cardiac troponin levels were markedly elevated. The patient showed no signs or symptoms of acute heart failure. Cardiopulmonary auscultation revealed no murmurs or palpable thrills over the precordium, and chest radiography was unremarkable. Coronary angiography demonstrated ostial occlusion of the left anterior descending artery (LAD), severe stenosis of the intermediate branch, significant double stenosis of the proximal and mid circumflex artery, and critical proximal stenosis of the right coronary artery (RCA). An attempt at percutaneous coronary intervention (PCI) of the LAD was unsuccessful. Preoperative transthoracic echocardiography (TTE) showed a left ventricular ejection fraction (LVEF) of 35%, mild left ventricular hypertrophy, apical akinesia, marked hypokinesia of the inferior and inferolateral walls, mild mitral regurgitation, and no pericardial effusion. The patient subsequently underwent CABG via median sternotomy with cardiopulmonary bypass. Myocardial protection was achieved with aortic cross-clamping and intermittent cold blood cardioplegia delivered into the aortic root every 15 minutes. Complete surgical revascularization was performed using a skeletonized left internal thoracic artery grafted to the LAD, and saphenous vein grafts to the first diagonal branch (D1), the obtuse marginal branch (M1), and the RCA. The intraoperative course was uneventful, and weaning from cardiopulmonary bypass was achieved without difficulty. No mechanical circulatory support, including intra-aortic balloon pump, Impella, or extracorporeal membrane oxygenation, was required perioperatively. On postoperative day 2, routine TTE revealed a focal excavation of the mid-interventricular septum. Further evaluation with transesophageal echocardiography (TEE) demonstrated an endocardial-contained rupture on the right ventricular aspect of the septum without communication between the two ventricular chambers, and without evidence of left-to-right shunt or right ventricular dysfunction (Video 1–2). The patient remained hemodynamically stable, with preserved systemic blood pressure and adequate urine output. Given this stability, a conservative management strategy with close echocardiographic surveillance was adopted to monitor for progression to complete septal rupture. The intraseptal cavity appeared as a rounded space with internal blood flow. Subsequent TEE confirmed a 3 × 3 cm pseudoaneurysm with early intraluminal thrombosis (Fig. 1) and preserved integrity of the right ventricular septal surface. LVEF improved slightly to 40%, with persistent mild mitral regurgitation. Considering the potential thromboembolic risk, anticoagulation with titrated enoxaparin in addition to aspirin (100 mg daily) was initiated. The postoperative course was uneventful, and the patient was discharged home on postoperative day 20 with referral to cardiac rehabilitation. Follow-up TTE demonstrated progressive spontaneous thrombosis of the pseudoaneurysm and complete closure of the septal defect (Video 3). Anticoagulation therapy was subsequently discontinued, and dual antiplatelet therapy with aspirin 100 mg and clopidogrel 75 mg daily was prescribed for 12 months in accordance with current ESC recommendations [3]. A TTE performed six months after surgery confirmed complete closure of the pseudoaneurysm supporting the appropriateness of the conservative strategy (Video 4). Discussion Postoperative VSD or PSA formation after CABG is exceedingly rare and is usually associated with perioperative myocardial infarction, ischemic necrosis, or mechanical stress on vulnerable myocardial tissue. In the large cohort reported by Elbadawi et al., among 13,767 patients experiencing mechanical complications after myocardial infarction, 10,344 (75%) were classified within the VSD group [1]. The onset of heart failure or cardiogenic shock, together with the size and anatomical location of the defect, plays a pivotal role in determining both the timing and type of intervention [4]. Nevertheless, delayed septal complications following myocardial revascularization remain poorly characterized in the literature [5] [6]. In the case we present, the cause of PSA is probably due to infarction of the septal myocardium before surgery, followed by localized weakening of septum and pseudoaneurysm development once surgical reperfusion occurred. In the present case, the PSA likely resulted from preoperative septal infarction leading to localized myocardial weakening, with subsequent formation of an intraseptal cavity after surgical reperfusion. Post-reperfusion VSDs frequently require urgent surgical or percutaneous closure due to hemodynamic instability or significant shunt flow [7]. Similarly, ventricular aneurysms and PSA often necessitate surgical treatment, as percutaneous options remain limited [8]. Compared with true aneurysms, pseudoaneurysms carry a higher risk of expansion or rupture and are therefore commonly managed invasively [9]. Structurally, ventricular aneurysms involve all layers of the myocardial wall, whereas pseudoaneurysms represent contained ruptures bounded by adherent pericardium or fibrotic tissue [10]. The choice between surgical repair and transcatheter closure must be individualized, taking into account defect complexity, anatomical location, device availability, operator expertise, and the patient’s overall clinical condition [11]. However, in the absence of a significant interventricular shunt and in clinically stable patients, a conservative strategy may represent a reasonable alternative. Conservative management has been previously described in selected cases, including the report by Maffè et al. [12], and isolated examples of conservatively treated post-infarction pseudoaneurysms have also been published by Zito and colleagues [13]. In our patient, serial TTE demonstrated progressive thrombosis and eventual spontaneous closure of the pseudoaneurysm. Such spontaneous resolution remains exceptional, and its natural course likely depends on factors including defect size, extent of myocardial necrosis, and the balance of intracardiac pressures. Once communication between the ventricular chambers has been excluded, combined anticoagulation and antiplatelet therapy may be considered to reduce thromboembolic risk related to intraluminal thrombus formation, although treatment should be individualized according to imaging findings and clinical evolution. Additional imaging modalities such as cardiac computed tomography or cardiac magnetic resonance imaging may provide further insights into tissue viability and pseudoaneurysm morphology. In our case, however, serial TTE and TEE proved sufficient for diagnosis, risk stratification, and therapeutic monitoring, confirming echocardiography as the cornerstone of bedside assessment in these patients. Conclusion Early postoperative interventricular septal pseudoaneurysm or VSD after CABG is a rare but potentially life-threatening condition. In the absence of hemodynamic compromise or significant shunt flow, a conservative, imaging-guided strategy may be considered in carefully selected patients. This case adds to the limited evidence suggesting that spontaneous thrombosis and closure are possible under close clinical and echocardiographic surveillance. Declarations Author Contributions: A.R., L.A. and S.L. have given substantial contributions to the conception or the design of the manuscript, A.R., S.S., S.L. to acquisition, analysis and interpretation of the data. L.A., C.P. and U.B. have participated to drafting the manuscript, A.R. and S.L. revised it critically. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding. Informed Consent Statement: Informed consent was obtained from the patient to publish this paper. Data Availability Statement: The authors confirm that the data supporting the findings of this study are available within the article. Conflicts of Interest: The authors declare no conflict of interest. References Elbadawi A, Elgendy IY, Mahmoud K, Barakat AF, Mentias A, Mohamed AH, Ogunbayo GO, Megaly M, Saad M, Omer MA, Paniagua D, Abbott JD, Jneid H., «Temporal Trends and Outcomes of Mechanical Complications in Patients With Acute Myocardial Infarction.,» JACC Cardiovasc Interv. , Vol. %1 di %212(18):1825-1836. , 2019. Torchio F, Garatti A, Ronco D, Matteucci M, Massimi G, Lorusso R., «Left ventricular pseudoaneurysm: the niche of post-infarction mechanical complications.,» Ann Cardiothorac Surg., Vol. %1 di %211(3):290-298., 2022. Collet JP, Thiele H, Barbato E, Barthélémy O, Bauersachs J, Bhatt DL, Dendale P, Dorobantu M, Edvardsen T, Folliguet T, Gale CP, Gilard M, Jobs A, Jüni P, Lambrinou E, Lewis BS, Mehilli J, Meliga E, Merkely B, Mueller C, Roffi M, Rutten FH, Sibbing D, Sio, «2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation.,» Eur Heart J., Vol. %1 di %242(14):1289-1367., 2021. Goldberg RJ, Spencer FA, Gore JM, Lessard D, Yarzebski J. , «Thirty-year trends (1975 to 2005) in the magnitude of, management of, and hospital death rates associated with cardiogenic shock in patients with acute myocardial infarction: a population-based perspective.,» Circulation, Vol. %1 di %2119(9):1211-9., 2009. Rexha N, Krasniqi X, Dervishaj Rexha A, Bakalli A., «Overlooked Ventricular Septal Defect Post-Myocardial Infarction and Coronary Artery Bypass Grafting.,» Clin Med Insights Case Rep. , vol. 17:11795476241281442., 2024. Fiedler AG, Sundt TM III, Tolis G., «Post-Myocardial Infarction Ventricular Septal Defect Six Months following Coronary Artery Bypass Grafting.,» Heart Surg Forum., Vol. %1 di %220(4):E162-E163., 2017. Park JY, Park SH, Oh JY, Kim IJ, Lee YH, Park SH, Kwon KH., «Delayed ventricular septal rupture after percutaneous coronary intervention in acute myocardial infarction.,» Korean J Intern Med., Vol. %1 di %220(3):243-6., 2005. Calvert PA, Cockburn J, Wynne D, Ludman P, Rana BS, Northridge D, Mullen MJ, Malik I, Turner M, Khogali S, Veldtman GR, Been M, Butler R, Thomson J, Byrne J, MacCarthy P, Morrison L, Shapiro LM, Bridgewater B, de Giovanni J, Hildick-Smith D., «Percutaneous closure of postinfarction ventricular septal defect: in-hospital outcomes and long-term follow-up of UK experience.,» Circulation. , Vol. %1 di %2129(23):2395-402, 2014. Durko AP, Budde RPJ, Geleijnse ML, Kappetein AP., «Recognition, assessment and management of the mechanical complications of acute myocardial infarction.,» Heart., Vol. %1 di %2104(14):1216-1223. , 2018. Jamil D, Fadel R, Kollman P, Swanson B., «A Case of an Interventricular Septum Pseudoaneurysm With Perforation Mimicking a Ventricular Septal Defect.,» Cureus. , vol. 16(11):e73080. , 2024. Omar S, Morgan GL, Panchal HB, Thourani V, Rihal CS, Patel R, Kherada N, Egbe AC, Beohar N., «Management of post-myocardial infarction ventricular septal defects: A critical assessment.,» J Interv Cardiol., Vol. %1 di %231(6):939-948., 2018. Maffe' S, Zenone F, Paffoni P, Pardo NF, Dellavesa P, Perucca A, Parravicini U, Paino AM, Bielli M, Signorotti F, Zanetta M, «Left ventricular pseudoaneurysm: an atypical case associated with a small ventricular septal defect.,» J Cardiovasc Med (Hagerstown), Vol. %1 di %29(2):195-200. , 2008. Zito C, Di Bella G, Oreto G, Longordo C, Cusmà-Piccione M, Lentini S, Carerj S. , «Cardiac imaging in subepicardial aneurysm.,» J Cardiovasc Med (Hagerstown), Vol. %1 di %212(8):605-7. , 2011. Additional Declarations No competing interests reported. Supplementary Files Video1.mp4 Video 1. Endocardial rupture on the right ventricular septum. Video2.mp4 Video 2. Absence of left-to-right shunt. Video3.mp4 Video 3. Progressive spontaneous thrombosis of the pseudoaneurysm and complete closure of the septal defect. Video4.mp4 Video 4. Complete closure of the pseudoaneurysm. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 06 Apr, 2026 Reviews received at journal 03 Apr, 2026 Reviews received at journal 02 Apr, 2026 Reviewers agreed at journal 01 Apr, 2026 Reviewers agreed at journal 31 Mar, 2026 Reviews received at journal 28 Mar, 2026 Reviewers agreed at journal 27 Mar, 2026 Reviewers invited by journal 27 Mar, 2026 Editor assigned by journal 05 Mar, 2026 Submission checks completed at journal 05 Mar, 2026 First submitted to journal 23 Feb, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8950917","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":613622867,"identity":"e3b94ccd-6766-40f4-8418-4c1881bed083","order_by":0,"name":"Alessandro Ricasoli","email":"","orcid":"","institution":"University of Catania","correspondingAuthor":false,"prefix":"","firstName":"Alessandro","middleName":"","lastName":"Ricasoli","suffix":""},{"id":613622868,"identity":"12572c1f-c1fb-4034-b147-59ec9f647474","order_by":1,"name":"Laura Asta","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzklEQVRIiWNgGAWjYBACPgST+QADgwFDAgMzAS1sMAYPA1sCVAsBPUhaeAxANFAfIS3sZ8w+/GCws7dnP/NNuqDALo+Bnf8Afi08OcYzexiSE3t4crdJzzBILibCYTnGQEcxJ/AwALXwGBxIbCCohf+NMeMfhnp7Hv43z4jUIpFjzMzDcJixRyKHjVgtz4qZZQyOJ/bceGZszWOQnNjGzGyAVws/f/JmxjcV1fbs/ckPb/P8sUvs5z/4AL81YIBsLBtOVaNgFIyCUTAKiAYAinYyduz9O7AAAAAASUVORK5CYII=","orcid":"","institution":"University “G.d’Annunzio” Chieti \u0026 Pescara","correspondingAuthor":true,"prefix":"","firstName":"Laura","middleName":"","lastName":"Asta","suffix":""},{"id":613622869,"identity":"f6c243f8-b96c-4aeb-a1b7-0b6a6e9a9a0a","order_by":2,"name":"Salvatore Scandura","email":"","orcid":"","institution":"Azienda Ospedaliera Universitaria Policlinico ‘G. 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Endocardial rupture on the right ventricular septum.\u003c/p\u003e","description":"","filename":"Video1.mp4","url":"https://assets-eu.researchsquare.com/files/rs-8950917/v1/a543a990dff4b540729a584d.mp4"},{"id":105879475,"identity":"70000831-0102-4aab-8236-f6ce37ff5b05","added_by":"auto","created_at":"2026-04-01 06:26:16","extension":"mp4","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":12779595,"visible":true,"origin":"","legend":"\u003cp\u003eVideo 2. Absence of left-to-right shunt.\u003c/p\u003e","description":"","filename":"Video2.mp4","url":"https://assets-eu.researchsquare.com/files/rs-8950917/v1/6f7208db380ac4ddac5a9891.mp4"},{"id":105879373,"identity":"ccc20b1e-d14f-4250-bcc6-a237a728defc","added_by":"auto","created_at":"2026-04-01 06:25:58","extension":"mp4","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":17913831,"visible":true,"origin":"","legend":"\u003cp\u003eVideo 3. Progressive spontaneous thrombosis of the pseudoaneurysm and complete closure of the septal defect.\u003c/p\u003e","description":"","filename":"Video3.mp4","url":"https://assets-eu.researchsquare.com/files/rs-8950917/v1/047ddc20f7f57c1f93702ac5.mp4"},{"id":105879384,"identity":"57db7928-fdd0-4f2c-9800-6eaebfa1cf1c","added_by":"auto","created_at":"2026-04-01 06:26:01","extension":"mp4","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":11161214,"visible":true,"origin":"","legend":"\u003cp\u003eVideo 4. Complete closure of the pseudoaneurysm.\u003c/p\u003e","description":"","filename":"Video4.mp4","url":"https://assets-eu.researchsquare.com/files/rs-8950917/v1/cd05c7680aa6cc43ca5b2a9a.mp4"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impending Interventricular Septal Rupture After CABG: Conservative Management of a Post-Infarction Septal Pseudoaneurysm","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePost-infarction ventricular septal defect (VSD) is an uncommon but life-threatening mechanical complication that typically develops within the first 2\u0026ndash;7 days after myocardial infarction. In the contemporary percutaneous coronary intervention (PCI) era, the incidence of mechanical complications remains low\u0026mdash;approximately 0.27% in STEMI and 0.06% in NSTEMI patients\u0026mdash;without significant temporal variation [1]. Unlike true VSDs, ventricular pseudoaneurysms (PSAs) are contained by pericardium or fibrotic tissue, which limits free rupture and prevents uncontrolled blood extravasation beyond the ventricular cavity [2]. Although most PSAs occur in the acute post-infarction setting, delayed septal complications have also been reported after myocardial revascularization procedures [3]. Herein, we describe a case of an early postoperative interventricular septal pseudoaneurysm developing after coronary artery bypass grafting (CABG), initially mimicking an impending septal defect. We discuss the diagnostic challenges, therapeutic strategy, and clinical outcome, emphasizing the role of multimodality imaging and individualized management.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eA 61-year-old Caucasian male with a history of hypertension, type 2 diabetes mellitus, and obesity presented with anterior ST-segment elevation myocardial infarction (STEMI). Cardiac troponin levels were markedly elevated. The patient showed no signs or symptoms of acute heart failure. Cardiopulmonary auscultation revealed no murmurs or palpable thrills over the precordium, and chest radiography was unremarkable. Coronary angiography demonstrated ostial occlusion of the left anterior descending artery (LAD), severe stenosis of the intermediate branch, significant double stenosis of the proximal and mid circumflex artery, and critical proximal stenosis of the right coronary artery (RCA). An attempt at percutaneous coronary intervention (PCI) of the LAD was unsuccessful.\u003c/p\u003e \u003cp\u003ePreoperative transthoracic echocardiography (TTE) showed a left ventricular ejection fraction (LVEF) of 35%, mild left ventricular hypertrophy, apical akinesia, marked hypokinesia of the inferior and inferolateral walls, mild mitral regurgitation, and no pericardial effusion. The patient subsequently underwent CABG via median sternotomy with cardiopulmonary bypass. Myocardial protection was achieved with aortic cross-clamping and intermittent cold blood cardioplegia delivered into the aortic root every 15 minutes. Complete surgical revascularization was performed using a skeletonized left internal thoracic artery grafted to the LAD, and saphenous vein grafts to the first diagonal branch (D1), the obtuse marginal branch (M1), and the RCA. The intraoperative course was uneventful, and weaning from cardiopulmonary bypass was achieved without difficulty. No mechanical circulatory support, including intra-aortic balloon pump, Impella, or extracorporeal membrane oxygenation, was required perioperatively.\u003c/p\u003e \u003cp\u003eOn postoperative day 2, routine TTE revealed a focal excavation of the mid-interventricular septum. Further evaluation with transesophageal echocardiography (TEE) demonstrated an endocardial-contained rupture on the right ventricular aspect of the septum without communication between the two ventricular chambers, and without evidence of left-to-right shunt or right ventricular dysfunction (Video 1\u0026ndash;2).\u003c/p\u003e \u003cp\u003eThe patient remained hemodynamically stable, with preserved systemic blood pressure and adequate urine output. Given this stability, a conservative management strategy with close echocardiographic surveillance was adopted to monitor for progression to complete septal rupture. The intraseptal cavity appeared as a rounded space with internal blood flow. Subsequent TEE confirmed a 3 \u0026times; 3 cm pseudoaneurysm with early intraluminal thrombosis (Fig.\u0026nbsp;1) and preserved integrity of the right ventricular septal surface. LVEF improved slightly to 40%, with persistent mild mitral regurgitation. Considering the potential thromboembolic risk, anticoagulation with titrated enoxaparin in addition to aspirin (100 mg daily) was initiated.\u003c/p\u003e \u003cp\u003eThe postoperative course was uneventful, and the patient was discharged home on postoperative day 20 with referral to cardiac rehabilitation. Follow-up TTE demonstrated progressive spontaneous thrombosis of the pseudoaneurysm and complete closure of the septal defect (Video 3). Anticoagulation therapy was subsequently discontinued, and dual antiplatelet therapy with aspirin 100 mg and clopidogrel 75 mg daily was prescribed for 12 months in accordance with current ESC recommendations [3]. A TTE performed six months after surgery confirmed complete closure of the pseudoaneurysm supporting the appropriateness of the conservative strategy (Video 4).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003ePostoperative VSD or PSA formation after CABG is exceedingly rare and is usually associated with perioperative myocardial infarction, ischemic necrosis, or mechanical stress on vulnerable myocardial tissue. In the large cohort reported by Elbadawi et al., among 13,767 patients experiencing mechanical complications after myocardial infarction, 10,344 (75%) were classified within the VSD group [1]. The onset of heart failure or cardiogenic shock, together with the size and anatomical location of the defect, plays a pivotal role in determining both the timing and type of intervention [4]. Nevertheless, delayed septal complications following myocardial revascularization remain poorly characterized in the literature [5] [6].\u003c/p\u003e \u003cp\u003eIn the case we present, the cause of PSA is probably due to infarction of the septal myocardium before surgery, followed by localized weakening of septum and pseudoaneurysm development once surgical reperfusion occurred.\u003c/p\u003e \u003cp\u003eIn the present case, the PSA likely resulted from preoperative septal infarction leading to localized myocardial weakening, with subsequent formation of an intraseptal cavity after surgical reperfusion. Post-reperfusion VSDs frequently require urgent surgical or percutaneous closure due to hemodynamic instability or significant shunt flow [7].\u003c/p\u003e \u003cp\u003eSimilarly, ventricular aneurysms and PSA often necessitate surgical treatment, as percutaneous options remain limited [8]. Compared with true aneurysms, pseudoaneurysms carry a higher risk of expansion or rupture and are therefore commonly managed invasively [9]. Structurally, ventricular aneurysms involve all layers of the myocardial wall, whereas pseudoaneurysms represent contained ruptures bounded by adherent pericardium or fibrotic tissue [10].\u003c/p\u003e \u003cp\u003eThe choice between surgical repair and transcatheter closure must be individualized, taking into account defect complexity, anatomical location, device availability, operator expertise, and the patient\u0026rsquo;s overall clinical condition [11].\u003c/p\u003e \u003cp\u003eHowever, in the absence of a significant interventricular shunt and in clinically stable patients, a conservative strategy may represent a reasonable alternative. Conservative management has been previously described in selected cases, including the report by Maff\u0026egrave; et al. [12], and isolated examples of conservatively treated post-infarction pseudoaneurysms have also been published by Zito and colleagues [13].\u003c/p\u003e \u003cp\u003eIn our patient, serial TTE demonstrated progressive thrombosis and eventual spontaneous closure of the pseudoaneurysm. Such spontaneous resolution remains exceptional, and its natural course likely depends on factors including defect size, extent of myocardial necrosis, and the balance of intracardiac pressures. Once communication between the ventricular chambers has been excluded, combined anticoagulation and antiplatelet therapy may be considered to reduce thromboembolic risk related to intraluminal thrombus formation, although treatment should be individualized according to imaging findings and clinical evolution.\u003c/p\u003e \u003cp\u003eAdditional imaging modalities such as cardiac computed tomography or cardiac magnetic resonance imaging may provide further insights into tissue viability and pseudoaneurysm morphology. In our case, however, serial TTE and TEE proved sufficient for diagnosis, risk stratification, and therapeutic monitoring, confirming echocardiography as the cornerstone of bedside assessment in these patients.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eEarly postoperative interventricular septal pseudoaneurysm or VSD after CABG is a rare but potentially life-threatening condition. In the absence of hemodynamic compromise or significant shunt flow, a conservative, imaging-guided strategy may be considered in carefully selected patients. This case adds to the limited evidence suggesting that spontaneous thrombosis and closure are possible under close clinical and echocardiographic surveillance.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u003c/strong\u003e A.R., L.A. and S.L. have given substantial contributions to the conception or the design of the manuscript, A.R., S.S., S.L. to acquisition, analysis and interpretation of the data. L.A., C.P. and U.B. have participated to drafting the manuscript, A.R. and S.L. revised it critically. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e This research received no external funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed Consent Statement:\u003c/strong\u003e Informed consent was obtained from the patient to publish this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement:\u003c/strong\u003e The authors confirm that the data supporting the findings of this study are available within the article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of Interest:\u003c/strong\u003e The authors declare no conflict of interest.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eElbadawi A, Elgendy IY, Mahmoud K, Barakat AF, Mentias A, Mohamed AH, Ogunbayo GO, Megaly M, Saad M, Omer MA, Paniagua D, Abbott JD, Jneid H., \u0026laquo;Temporal Trends and Outcomes of Mechanical Complications in Patients With Acute Myocardial Infarction.,\u0026raquo; JACC Cardiovasc Interv. , Vol. %1 di %212(18):1825-1836. , 2019. \u003c/li\u003e\n\u003cli\u003eTorchio F, Garatti A, Ronco D, Matteucci M, Massimi G, Lorusso R., \u0026laquo;Left ventricular pseudoaneurysm: the niche of post-infarction mechanical complications.,\u0026raquo; Ann Cardiothorac Surg., Vol. %1 di %211(3):290-298., 2022. \u003c/li\u003e\n\u003cli\u003eCollet JP, Thiele H, Barbato E, Barth\u0026eacute;l\u0026eacute;my O, Bauersachs J, Bhatt DL, Dendale P, Dorobantu M, Edvardsen T, Folliguet T, Gale CP, Gilard M, Jobs A, J\u0026uuml;ni P, Lambrinou E, Lewis BS, Mehilli J, Meliga E, Merkely B, Mueller C, Roffi M, Rutten FH, Sibbing D, Sio, \u0026laquo;2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation.,\u0026raquo; Eur Heart J., Vol. %1 di %242(14):1289-1367., 2021. \u003c/li\u003e\n\u003cli\u003eGoldberg RJ, Spencer FA, Gore JM, Lessard D, Yarzebski J. , \u0026laquo;Thirty-year trends (1975 to 2005) in the magnitude of, management of, and hospital death rates associated with cardiogenic shock in patients with acute myocardial infarction: a population-based perspective.,\u0026raquo; Circulation, Vol. %1 di %2119(9):1211-9., 2009. \u003c/li\u003e\n\u003cli\u003eRexha N, Krasniqi X, Dervishaj Rexha A, Bakalli A., \u0026laquo;Overlooked Ventricular Septal Defect Post-Myocardial Infarction and Coronary Artery Bypass Grafting.,\u0026raquo; Clin Med Insights Case Rep. , vol. 17:11795476241281442., 2024. \u003c/li\u003e\n\u003cli\u003eFiedler AG, Sundt TM III, Tolis G., \u0026laquo;Post-Myocardial Infarction Ventricular Septal Defect Six Months following Coronary Artery Bypass Grafting.,\u0026raquo; Heart Surg Forum., Vol. %1 di %220(4):E162-E163., 2017. \u003c/li\u003e\n\u003cli\u003ePark JY, Park SH, Oh JY, Kim IJ, Lee YH, Park SH, Kwon KH., \u0026laquo;Delayed ventricular septal rupture after percutaneous coronary intervention in acute myocardial infarction.,\u0026raquo; Korean J Intern Med., Vol. %1 di %220(3):243-6., 2005. \u003c/li\u003e\n\u003cli\u003eCalvert PA, Cockburn J, Wynne D, Ludman P, Rana BS, Northridge D, Mullen MJ, Malik I, Turner M, Khogali S, Veldtman GR, Been M, Butler R, Thomson J, Byrne J, MacCarthy P, Morrison L, Shapiro LM, Bridgewater B, de Giovanni J, Hildick-Smith D., \u0026laquo;Percutaneous closure of postinfarction ventricular septal defect: in-hospital outcomes and long-term follow-up of UK experience.,\u0026raquo; Circulation. , Vol. %1 di %2129(23):2395-402, 2014. \u003c/li\u003e\n\u003cli\u003eDurko AP, Budde RPJ, Geleijnse ML, Kappetein AP., \u0026laquo;Recognition, assessment and management of the mechanical complications of acute myocardial infarction.,\u0026raquo; Heart., Vol. %1 di %2104(14):1216-1223. , 2018. \u003c/li\u003e\n\u003cli\u003eJamil D, Fadel R, Kollman P, Swanson B., \u0026laquo;A Case of an Interventricular Septum Pseudoaneurysm With Perforation Mimicking a Ventricular Septal Defect.,\u0026raquo; Cureus. , vol. 16(11):e73080. , 2024. \u003c/li\u003e\n\u003cli\u003eOmar S, Morgan GL, Panchal HB, Thourani V, Rihal CS, Patel R, Kherada N, Egbe AC, Beohar N., \u0026laquo;Management of post-myocardial infarction ventricular septal defects: A critical assessment.,\u0026raquo; J Interv Cardiol., Vol. %1 di %231(6):939-948., 2018. \u003c/li\u003e\n\u003cli\u003eMaffe\u0026apos; S, Zenone F, Paffoni P, Pardo NF, Dellavesa P, Perucca A, Parravicini U, Paino AM, Bielli M, Signorotti F, Zanetta M, \u0026laquo;Left ventricular pseudoaneurysm: an atypical case associated with a small ventricular septal defect.,\u0026raquo; J Cardiovasc Med (Hagerstown), Vol. %1 di %29(2):195-200. , 2008. \u003c/li\u003e\n\u003cli\u003eZito C, Di Bella G, Oreto G, Longordo C, Cusm\u0026agrave;-Piccione M, Lentini S, Carerj S. , \u0026laquo;Cardiac imaging in subepicardial aneurysm.,\u0026raquo; J Cardiovasc Med (Hagerstown), Vol. %1 di %212(8):605-7. , 2011. \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-cardiothoracic-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jcts","sideBox":"Learn more about [Journal of Cardiothoracic Surgery](http://cardiothoracicsurgery.biomedcentral.com)","snPcode":"13019","submissionUrl":"https://submission.nature.com/new-submission/13019/3","title":"Journal of Cardiothoracic Surgery","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Ventricular septal defect, Myocardial Infarction, Pseudoaneurysm, Interventricular Septum","lastPublishedDoi":"10.21203/rs.3.rs-8950917/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8950917/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e: Ventricular septal defect is a rare yet life-threatening mechanical complication of myocardial infarction. In exceptionally uncommon cases, the interventricular septum undergoes localized dissection with formation of an intraseptal pseudoaneurysm without complete septal rupture. While most pseudoaneurysms develop in the acute post-infarction phase, delayed presentation following surgical revascularization is exceedingly rare.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase Summary\u003c/strong\u003e: We report the case of a 61-year-old man who underwent surgical coronary artery bypass grafting after myocardial infarction. Early postoperative transesophageal echocardiography identified a 3 × 3 cm mid-septal pseudoaneurysm without communication between the two ventricular chambers. Given the patient’s hemodynamic stability, a conservative strategy with combined anticoagulation and antiplatelet therapy was adopted. Serial transesophageal echocardiographic follow-up demonstrated progressive spontaneous thrombosis and complete closure of the pseudoaneurysm. At six months, the patient remained asymptomatic with preserved left ventricular function.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDiscussion\u003c/strong\u003e: Post-CABG interventricular septal pseudoaneurysm is an exceptionally rare finding. In carefully selected hemodynamically stable patients, conservative management may represent a reasonable alternative to surgery, as spontaneous thrombosis and resolution can occur. Close echocardiographic surveillance is essential to guide therapeutic decisions and promptly detect complications.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e: This case highlights that early diagnosis and individualized management of post-CABG interventricular septal pseudoaneurysm may lead to favorable outcomes without surgical intervention in selected stable patients.\u003c/p\u003e","manuscriptTitle":"Impending Interventricular Septal Rupture After CABG: Conservative Management of a Post-Infarction Septal Pseudoaneurysm","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-01 06:23:41","doi":"10.21203/rs.3.rs-8950917/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-06T07:14:50+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-03T10:44:10+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-02T05:27:25+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"338682477612985687826042659011930674003","date":"2026-04-01T22:40:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"156954046316871325514280503777555670846","date":"2026-03-31T06:40:13+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-28T05:45:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"305610123383150968837400707661251031212","date":"2026-03-27T16:58:45+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-27T16:44:39+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-06T04:02:36+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-06T04:02:07+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Cardiothoracic Surgery","date":"2026-02-23T21:56:31+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-cardiothoracic-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jcts","sideBox":"Learn more about [Journal of Cardiothoracic Surgery](http://cardiothoracicsurgery.biomedcentral.com)","snPcode":"13019","submissionUrl":"https://submission.nature.com/new-submission/13019/3","title":"Journal of Cardiothoracic Surgery","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ed58ac17-a02b-4921-86bd-e52be6d99f92","owner":[],"postedDate":"April 1st, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-21T07:38:13+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-01 06:23:41","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8950917","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8950917","identity":"rs-8950917","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}