Correlating the morphological features of tetralogy of Fallot and the Eisenmenger malformation

Abstract

We studied a series of 43 autopsied cases of tetralogy of Fallot, assessing the mode of insertion of the outlet septum relative to the limbs of the septomarginal trabeculation, and compared the findings in retrospective fashion with our previous observations of a group of hearts with the so-called Eisenmenger malformation. In the majority of hearts with tetralogy of Fallot, the outlet septum inserted frontally relative to the septomarginal trabeculation, but in a minority of cases the outlet septum inserted in lateral fashion, as had been observed in all our hearts studied with the Eisenmenger malformation. The different modes of insertion were found to correlate, first, with the axis of anatomical aortic rightward rotation, coincident with the commissure between the right coronary and the left coronary leaflets of the aortic valve. The different modes of insertion of the outlet septum also correlated with the level of attachment of the arterial valvar leaflets on its subpulmonary and subaortic surfaces; concomitantly, correlation was found between the length of the subpulmonary infundibulum and the length of the muscular outlet septum itself. In the majority of hearts showing tetralogy of Fallot, the elongated infundibulum was also uniformly narrow, but in a minority the infundibulum was well expanded, obstructed only at its mouth, but widening at the valvar level. In all the hearts with the Eisenmenger malformation, in contrast, the unobstructed infundibulum was well expanded. The morphological findings of the present study show unequivocally that tetralogy of Fallot and Eisenmenger malformation are two phenotypically different congenital cardiac anomalies.

Genetic anomalies in fetuses with tetralogy of Fallot by using high-definition chromosomal microarray analysis

“…Fetal tetralogy of Fallot (TOF) and its variants comprise ventricular septal defect, overriding aorta and outflow obstruction of right ventricle, with an occurrence of about 8–12% in infants suffering with congenital heart diseases (CHDs) [1, 2]. A combination of anterocephalad deviation of the outlet septum and abnormal septoparietal trabeculations is now accepted as the hallmark of TOF [3]. The etiology of TOF is complex and the genesis of TOF has been associated with environmental factors and genetic disorders, including chromosomal anomalies, aneuploidies, 22q11.2 deletion and single-gene disease.…”

Transpositions of the great arteries versus aortic dextropositions. A review of some embryogenetic and morphological aspects

“…Indeed, we consider that AD defects occur when the septal end of the conal infundibular septum (dextrodorsal conal ridge) is related to the anterosuperior division (limb) of the septal band or septomarginal trabeculation (SMT), as expected under normal conditions, but with an anteriorly deviated conal infundibular septum, thus producing a subaortic VSD and aortic dextroposition (Figure 1a). It must be specifically noted that all Eisenmenger cases (Restivo et al, 2016) and an extremely few tetralogy of Fallot cases (Restivo et al, 2017) show an identical type of lateral fusion between the infundibular septum and the lateral edge of…”

Four-dimensional flow cardiovascular magnetic resonance in tetralogy of Fallot: a systematic review

“…Author details 1 Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand. 2 Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.…”

“…Tetralogy of Fallot (TOF) is a common serious form of congenital heart disease (CHD) and one of the first to be formally described historically [1][2][3][4]. The four main morphological features are (i) ventricular septal defect (VSD), (ii) right ventricular (RV) outflow tract obstruction, (iii) overriding aorta and iv) RV hypertrophy.…”