A Case of an Interventricular Septum Pseudoaneurysm With Perforation Mimicking a Ventricular Septal Defect.

Ventricular pseudoaneurysm (PSA) is a ventricular outpouching contained by adherent pericardium or myocardial scar tissue and represents a rare but potentially fatal complication of acute myocardial infarction (AMI). The vast majority of cases involve the left ventricular apex, in the area of infarct. It is extremely rare to see PSA formation within the interventricular septum (IVS). We present a case of ventricular PSA of the IVS, with contained perforation into the right ventricle, mimicking a ventricular septal defect (VSD) in a patient presenting with ST-elevation myocardial infarction (STEMI). This case underscores the importance of maintaining a high index of clinical suspicion and reviews the pathophysiological mechanisms and treatment options for these life-threatening mechanical complications.