Rupture of the IVS is a mechanical complication of acute myocardial infarction (AMI), rare since the spread of percutaneous coronary revascularisation techniques. In a recent US case study, it was documented in 0.25% of cases. However, it is something to think about in the event of unexpected, rapid haemodynamic deterioration.
We report the case of a 73-year-old man with a clinical history of COPD in heavy smoker, who was admitted on 04/14/2022 for a sub-acute inferior MI. After percutaneous revascularisation of the circumflex artery, the patient (pt) was discharged clinically stable. On transthoracic echocardiogram (TTE), the left ventricle (LV) appeared normal in size, with a large proximal inferior wall aneurysm (A) and slightly reduced global systolic function (EF = 45%). On 09/16/2022 admission to surgery for gastric perforation peritonitis from abuse of non-steroidal anti-inflammatory drugs. The pt survived the surgery without cardiac complications and remained well-compensated and asymptomatic in the following months. On 06/23/2023 new admission for heart failure: worsening dyspnoea and pulmonary and systemic congestion. The TTE showed a dilated LV (TDV = 162 ml), infero-lateral akinesia, a mid-basal inferior wall A and moderate global systolic dysfunction (EF = 40%). High velocity systolic flow was also documented in the right ventricle, which appeared to originate from an aneurysmal portion of the posterior IVS in continuity with the inferior wall A (Fig.1-2). Cardiac MRI confirmed the presence of a postinfarct PA involving the inferior wall and the basal and middle IVS with multiple jets responsible for significant left-right shunt (Qp/Qs = 2.9). Once clinical stabilisation was achieved, the pt was referred for cardiac surgery for direct closure of the interatrial defect and endoventriculoplasty. After the early postoperative phase, characterised by the need for pharmacological and mechanical haemodynamic support, there was a progressive clinical improvement.
PA is most frequently localised infero-posteriorly, and is distinguished from A by its narrow collar (ratio of collar diameter to aneurysm diameter < 0.5) and the absence of muscle tissue in the wall. 55% of PA are postischemic. They are classified, according to the distance from AMI, into acute (within 2 wks), subacute (between 2 wks and 3 mth) and chronic (after 3 mth); chronic PA are often large and asymptomatic but easily rupture, causing, as in our case, a late complication of the AMI.
