Aneurysm of the membranous septum detected during left ventriculography and demonstrated by cardiac magnetic resonance imaging

Isolated Aneurysms of the Membranous Ventricular Septum Without Residual Shunts: Systematic Review and Description of 3 Cases in Adults

“…Life‐threatening complications are related to thrombus formation, endocarditis, and related systemic emboli, persistent cardiac arrhythmias, and acute right‐to‐left shunts secondary to aneurysmal rupture. Overall, even if asymptomatic, membranous ventricular septal aneurysms are not as benign as previously thought (Figure ) …”

“…A variety of pathologic factors have been proposed to explain the occurrence of aneurysms at this location . The most common is spontaneous closure of a preexisting ventricular septal defect arising from the margins of the defect and usually incorporating the septal leaflet of the tricuspid valve . The rate of spontaneous closure of ventricular septal defects was 18.4% in 1873 patients in a single report .…”

“…The membranous interventricular septum is partly derived from the endocardial cushions and closely related to the cardiac valves and conduction system. Most cases are silent or discovered incidentally by cardiac imaging; others are associated with fatal complications . For membranous ventricular septal aneurysms to become clinically important, they have to interfere with the closure mechanism of the cardiac valves, cause a mass effect, or cause flow obstruction.…”

“…Most cases are silent or discovered incidentally by cardiac imaging; others are associated with fatal complications. 11,[15][16][17] For membranous ventricular septal aneurysms to become clinically important, they have to interfere with the closure mechanism of the cardiac valves, cause a mass effect, or cause flow obstruction. These aneurysms are hence implicated in the rapid progression of insufficiencies of both aortic and tricuspid valves due to leaflet prolapse (Venturi effect) or restriction of its movement.…”

Cardiac computed tomography can diagnose the tricuspid valve pouch

“…There have been no previous reports of diagnosing a tricuspid valve pouch by cardiac CT. With regard to AMS, there have been a few reports that have diagnosed AMS non-invasively by cardiac CT [4] or MRI [5], and some investigators recommend MRI to diagnose AMS because it can be done without any extra exposure to radiation or contrast medium [5]. However, cardiac CT has a superior spatial resolution in comparison to MRI.…”