We report the first successful Glenn procedure for pulmonary atresia with intact ventricular septum in the setting of D-transposition of the great arteries. This case was complicated by hypoplastic left ventricle and severe mitral regurgitation. Partial closure of the mitral valve at the time of Blalock-Taussig shunting resulted in improvement of heart failure.

Heart failure due to dilated cardiomyopathy is a major indication for paediatric cardiac transplantation. Endocardial fibroelastosis is a recognised pathological finding of unknown prognostic significance in paediatric dilated cardiomyopathy. To evaluate the nature of the association between left ventricular endocardial fibroelastosis and paediatric dilated cardiomyopathy, we reviewed surgical pathology reports of dilated cardiomyopathy explants (1986–2016) in order to characterise the pathological findings and to compare and contrast their frequency among four age groups: less than 1 year; 1–5 years; 6–10 years; and greater than 11 years. The 89 explants (47 males and 42 females) were all characterised by increased weight and left ventricular chamber dilatation without increased wall thickness. Ninety-five per cent of the specimens in the two youngest subsets had left ventricular endocardial fibroelastosis. Compared to the oldest age group, recipients aged 1–5 years had a 6-fold increase and those younger than 1 year a 19-fold increase in the odds of observing left ventricular endocardial fibroelastosis. Explants with and without endocardial fibroelastosis were otherwise phenotypically similar. In paediatric dilated cardiomyopathy endocardial fibroelastosis is a very common pathological finding, especially in infants and young children. We propose that the descriptive, clinico-pathological designation “Dilated Cardiomyopathy with Endocardial Fibroelastosis” should be adopted to facilitate future investigation into the potential prognostic/therapeutic significance of left ventricular endocardial fibroelastosis.

Borderline left ventricle refers to a spectrum of left ventricular underdevelopment, typically associated with other cardiac anomalies. The left ventricle may be mildly hypoplastic, as is sometimes seen accompanying aortic coarctation, or it can be severely hypoplastic, as is seen in hypoplastic left heart syndrome. For patients with a borderline left ventricle that is at either extreme, the treatment decision is relatively straightforward. Those with the most severe form of left ventricle hypoplasia will require single ventricle palliation or cardiac transplantation, whereas those with the mildest form may not need any intervention. It is the management strategy of children that fall within the grey zone of the spectrum, which continues to be controversial and remains variable within and among different institutions. Cardiac diseases with associated left ventricle hypoplasia include critical aortic stenosis, mitral stenosis, coarctation of the aorta, arch hypoplasia, cor triatriatum, unbalanced common atrioventricular canal, Shone’s complex, total anomalous pulmonary venous return, and complex conotruncal abnormalities. In this review, we will discuss the assessment and management of infants with borderline left ventricle with critical aortic stenosis or arch obstruction and associated mitral anomalies.

Hypoplastic left heart syndrome has the greatest mortality rate among all CHDs and without palliation is uniformly fatal. Despite noble efforts, the aetiology of this syndrome is unknown and a cure remains elusive. The genetic and anatomic heterogeneity of hypoplastic left heart syndrome supports a rethinking of old hypotheses and warrants further investigation into the histological and vascular variations recognised with this syndrome. In an effort to elucidate the pathogenesis of hypoplastic left heart syndrome, this review will focus on its unique myocardial and coronary pathology as well as evaluate the association of hypoplastic left heart syndrome with the endocardial fibroelastosis reaction.

Endocardial fibroelastosis is not a disease but a reaction of the endocardium. I review the history of the term with emphasis on the gradual understanding of the many causes of this reaction. I include a comprehensive list of diseases or other cardiac stresses that authors have reported in association, and I try to explain the mechanism of the reaction. Although endocardial fibroelastosis is rare today, I issue a warning of a possible epidemic recrudescence of some of the associated diseases. My hope is for nosologic purity, therefore that outworn but surviving concepts will be firmly rejected.

We present a case report of a pregnant woman with increased risk for trisomy 21 at first-trimester screening, assessed by ultrasonography, that was sent to our hospital. Amniocentesis was performed at 14 weeks and 2 days to obtain foetal karyotype that was normal (46,XX). At 19 weeks and 1 day, foetal hydrops associated with cardiac malformation was detected by routine scan. Foetal echocardiogram revealed a complete auriculoventricular septal defect, non-compacted myocardium, and a bradycardia of 70–90 beats per minute, which lead to the suspicion of left isomerism. Foetal death occurred at 20 weeks and 3 days. Autopsy was consistent with the prenatal diagnosis.

Diffuse endocardial thickening in dilated hearts has been considered as a distinct pathological entity, usually being termed endocardial fibroelastosis. It is common in infants and children and rare in adults. Current opinion holds that the endocardial thickening is a non-specific reaction to stress in the ventricular wall. Our personal observations point to the most severe forms occurring in young infants. To determine the frequency and severity of endocardial fibroelastosis in children with dilated cardiomyopathy, we studied 21 necropsy hearts, both grossly and microscopically. Ages of the patients ranged from two to 175 months (mean 46.5, median 23 months). Using a graduated eyepiece, we measured the endocardial thickness in samples from three sites in the left ventricle and one from the right ventricle. The values were compared to those obtained from similar measurements of the endocardium in hearts from four children presenting with tetralogy of Fallot. All the dilated hearts presented some degree of endocardial thickening. The gross detection of fibroelastosis depended on the degree of thickening. There was a negative but linear correlation between age and the mean endocardial thickness (r=0.70; p>0.001). Our findings support the concept that endocardial cells have greater replicative and secretory potentials in young patients, and that endocardial fibroelastosis is a secondary phenomenon in dilated hearts.

Various physiologic mechanisms have been proposed to account for the development of hypoplasia of the left heart. The mechanism thus far most widely accepted suggests that the entity starts as severe or critical aortic stenosis during fetal gestation. Obstruction at the level of the abnormal aortic valve is then held to increase left ventricular afterload, resulting in decreased systolic and diastolic function. Shunting across the patent oval foramen is then reversed, so that blood flows from left to right. This reversal of flow during fetal gestation decreases the volume of blood crossing the mitral valve, thus decreasing the further potential for growth of the left ventricle.1 Additional support for this postulated physiologic mechanism was provided with the advent of fetal echocardiography during the 1980s.2–4 It was the group of Allan, working at Guy's Hospital in London, which first documented the fetal development of hypoplasia of the left heart by serial echocardiographic observation.4 In their retrospective study of 7000 pregnancies, 462 fetuses were diagnosed to have a structural cardiac defect at the time of the initial echocardiogram. Among those, 28 patients had dilated and dysfunctional left ventricles and aortic valves. The majority of these patients were also found to have concomitant endocardial fibroelastosis. Out of 15 patients in the series who were followed with serial echocardiograms, five progressed to develop hypoplasia of the left heart. With echocardiographic technology undergoing refinement over the same period, it was during this era that the first fetal cardiac intervention was performed using echocardiographic guidance.2,5,6 With still further technologic advances, fetal diagnosis of hypoplasia of the left heart can now be made as early as 13 weeks gestational age.7 One entity which is frequently associated with the hypoplastic left ventricle and aortic stenosis is endocardial fibroelastosis. There is an overlap of pathology between these three entities.8–10 In this report, we describe our own experience in intervention in a fetus suspected of developing hypoplasia of the left heart.