The In Vivo Morphology of Post-Infarct Ventricular Septal Defect and the Implications for Closure

The aim of this study was to define the dynamic in vivo morphology of post-infarct ventricular septal defect (PIVSD), which has not been previously described in living patients.

PIVSD is a devastating complication of acute myocardial infarction.

The anatomic features of PIVSD, as demonstrated by computed tomography or magnetic resonance imaging, were retrospectively reviewed.

Thirty-two PIVSDs were assessed, 16 left coronary artery and 16 right coronary artery PIVSDs. PIVSDs were large (mean maximum dimension 26.5 ± 11.5 mm, mean area 5.2 ± 4.2 cm²) and oval (mean eccentricity index 1.7 ± 0.5), with thin margins (diastolic mean thickness 5 mm from the edge of the PIVSD 6.4 ± 3.0mm), and only 22% of PIVSDs were entirely confined to the septum. The defects could be larger in diastole or systole. The stem of the largest available Amplatzer occluder stem (St. Jude Medical, St. Paul, Minnesota) filled only 50% of defects. Patients with small defects may survive without closure. Without closure, those with large defects die. If accepted for closure, PIVSD size and coronary territory did not predict survival >1 year (overall 60%).

This is the first detailed anatomic description of PIVSD in living patients. Defects may be larger in systole or diastole, meaning that single-phase measurement is unsuitable. Its complex nature means that the most commonly available occluder device is frequently unsuitable. Successful closure leads to prolonged survival and should be attempted where possible. This study may lead to improved patient selection, closure techniques, and device design.