Poster 1016: Unrecognized Ventricular Septal Defect Post-Myocardial Infarction Cardiogenic Shock

Background: Myocardial infarction (MI) remains a leading cause of mortality worldwide. Ventricular septal defects (VSD) are a rare but life-threatening complication of MI. We present a case that highlights an unrecognized post-MI VSD as multiple visits to the emergency department for failure to thrive, progressing to cardiogenic shock.

Methods: A 66-year-old female with heart failure with preserved ejection fraction (HFpEF), moderate mitral regurgitation, and a recent NSTEMI treated with percutaneous coronary intervention presented with failure to thrive one month post-discharge. She had multiple emergency department visits for progressive dyspnea, weakness, weight loss, and anorexia before being transferred for further cardiac evaluation.
On admission, she exhibited a holosystolic murmur at the left lower sternal border with a palpable thrill, alongside her known murmur with axillary radiation. Laboratory results showed elevated BNP, decreased troponin, and increased D-dimer. Transthoracic echocardiography confirmed a ventricular septal defect (VSD) with a left-to-right shunt, an inferoseptal aneurysm, and mild pulmonary hypertension (Figures 1a-c and 2).
She was transferred to a tertiary center, where she developed cardiogenic shock requiring vasopressors, inotropes, and intra-aortic balloon pump (IABP) support as a bridge to surgical repair. On day 10, she underwent successful pericardial patch closure of the VSD, with postoperative transesophageal echocardiography confirming no residual shunting (Figure 1d). Unfortunately, patient required prolonged critical care support for MRSA pneumonia and hypoxic respiratory failure.

Outcome: VSD typically occurs 2–4 weeks post-MI and carries a high mortality rate if untreated. This case underscores the importance of recognizing acute changes in the physical examination and the importance of adequate auscultation. The cause of her failure to thrive was most likely secondary to VSD, which could have been discovered since her initial visits to the emergency department. The inability to recognize these findings in the setting of preexisting holosystolic murmur and heart failure is not surprising given her preexisting murmur and heart failure. Additionally, orthopnea is not a common symptom associated with VSD but could be explained by early cardiogenic shock and worsening mitral regurgitation post-MI.
Early referral to an advanced center with expertise in advanced heart failure and cardiothoracic surgery is paramount. While advanced mechanical circulatory support like ECMO and Impella has been employed in similar cases, this patient was successfully managed with vasopressors, inotropes, and IABP prior to open surgical repair.

Conclusion: This case underscores the importance of recognizing post-MI VSD as a rare but life-threatening complication and highlights the critical role of early referral to specialized centers with expertise in advanced heart failure and cardiothoracic surgery can optimize outcomes, even in resource-limited settings.