Large submitral left ventricular pseudoaneurysm following inferior wall ST-elevation myocardial infarction successfully managed with isolated Dor endoventricular circular patch plasty: a case report

Background Left ventricular (LV) pseudoaneurysm is an uncommon but potentially fatal mechanical complication of acute myocardial infarction (AMI) resulting from a contained ventricular free-wall rupture. Unlike a true aneurysm, a pseudoaneurysm lacks a myocardial wall and is contained by pericardial and fibrous tissue, predisposing it to expansion and rupture. Although timely reperfusion has reduced the incidence of post-infarction mechanical complications, delayed presentations continue to occur. Early diagnosis with multimodality imaging and appropriate surgical intervention are essential for favorable outcomes. Case presentation A 66-year-old man with type 2 diabetes mellitus and hypertension presented with progressively worsening exertional dyspnea (New York Heart Association class III) three months after successful primary percutaneous coronary intervention (PCI) for inferior wall ST-elevation myocardial infarction (STEMI). Transthoracic echocardiography demonstrated a giant submitral LV pseudoaneurysm measuring 67 × 49 × 68 mm, with a narrow 14-mm communication with the LV cavity. Cardiac magnetic resonance (CMR) confirmed a large inferolateral submitral pseudoaneurysm measuring 86 × 50 × 75 mm and demonstrated extensive transmural myocardial infarction with an infarct burden of approximately 31% of LV myocardial volume, as documented in the original CMR report. Preoperative coronary angiography showed a patent right coronary artery stent with only mild non-obstructive coronary artery disease, without an indication for concomitant coronary artery bypass grafting. The patient underwent successful isolated Dor endoventricular circular patch plasty using a bovine pericardial patch to exclude the pseudoaneurysm and restore LV geometry. Postoperative echocardiography demonstrated complete exclusion of the pseudoaneurysm, an intact patch, and no residual communication. LV ejection fraction remained stable or improved modestly from approximately 40% preoperatively to 45–50% at 6-month follow-up, with sustained symptomatic improvement. Conclusion A large submitral LV pseudoaneurysm should be considered in patients presenting with new or worsening heart failure symptoms after myocardial infarction, even in the absence of recurrent ischemia or elevated cardiac biomarkers. Multimodality imaging, particularly echocardiography and CMR, provides complementary information for diagnosis, tissue characterization, and surgical planning. In appropriately selected patients without significant obstructive coronary disease requiring revascularization, isolated Dor endoventricular circular patch plasty may provide effective exclusion of the pseudoaneurysm and restoration of LV geometry, with favorable short- to mid-term outcomes.