Morphological Characterization of Ventricular Septal Defect with Posterior Deviation of the Outlet Septum

Abstract

Ventricular septal defect (VSD) with posterior deviation of the outlet septum is frequently associated with left ventricular outflow obstruction and aortic arch anomalies. In this study, 17 patients with large VSD and posterior deviation of the outlet septum were evaluated. The VSD was further classified into ‘high’ and ‘low’ types according to the extension of the VSD; the high-type VSD (8 patients) extended mainly to the outlet or infundibular portion and the low-type VSD (9 patients) extended mainly to the trabecular or inlet portion. Related morphological features, such as outlet septum hypoplasia, muscle bundle between aortic-mitral valve junction, pulmonary artery overriding and aortic arch anomalies, were found more frequently in patients with high-type VSD, while tricuspid valve straddling and outlet septum hypertrophy were found more often in patients with low-type VSD. This classification for VSD with posterior deviation of the outlet septum helps to predict the morphological features of left ventricular outflow tract and aortic arch anomalies.

Understanding Left Ventricular Outflow Obstruction: Anatomoechocardiographic Correlation

“…It also originates a ventricular septal defect by septal malalignment and left ventricular hypertrophy. This often occurs with aortic interruption with bicuspid aorta but is quite rare in hearts with concordant ventriculoarterial connections, as in our case 6 . Left ventricular outflow tract obstructions secondary to posterior displacement of the infundibular septum, accessory mitral tissue, anomalous insertion of chordae tendineae, malposition of the mitral valve, and subaortic infundibulum have also been reported in association with complete transposition of great arteries 6,7 , 22–25 …”

“…They can occur as isolated abnormalities or associated with other congenital anomalies including ventricular septal defect 1–3 . Fixed subaortic obstructions vary depending on the structures involved, such as fibrous diaphragms, fibromuscular tunnels, accessory mitral tissue, anomalous insertion of the mitral valve chordae tendineae in the ventricular septum, or posterior displacement of the infundibular septum 4–8 . The dynamic subaortic obstruction of hypertrophic cardiomyopathy can be symmetric or asymmetric 9 …”

The Role of Tricuspid Valve Surgery in the Late Management of Tetralogy of Fallot

“…32 Echocardiography and cinecardioangiography demonstrate that a straddling tricuspid valve more commonly occurs with a perimembranous VSD with a trabecular or inlet extension than with other forms of VSD. 33 Although it is rare, double-orifice tricuspid valve has also been identified with TOF and TR. 34 Other congenital tricuspid anomalies are not consistently found with TOF, but they have been identified in 0.4% of patients.…”