Isolated double-chambered right ventricle presenting in adulthood

Congenital, acquired, or both? The only two congenitally based, acquired heart diseases

Discrete subaortic stenosis (DSS) is a type of left ventricular outflow tract obstruction whereas double-chambered right ventricle is a form of right ventricular outflow tract obstruction. Both of these cardiac malformations share lots of similar characteristics which classify them as acquired developmental heart diseases despite their congenital anatomical substrate. Both of them are frequently associated to ventricular septal defects. The initial stimulus in their pathogenetic process is anatomical abnormalities or variations. Subsequently, a hemodynamic process is triggered finally leading to an abnormal subaortic fibroproliferative process with regard to DSS or to hypertrophy of ectopic muscles as far as double-chambered right ventricle is concerned. In many cases, these pathologies are developed secondarily to surgical management of other congenital or acquired heart defects. Moreover, high recurrence rates after initial successful surgical therapy, particularly regarding DSS, have been described. Finally, an interesting coexistence of DSS and double-chambered aortic ventricle has also been reported in some cases.

Combined double chambered right ventricle, tricuspid valve dysplasia, ventricular septal defect, and subaortic stenosis in a dog

BACKGROUND

Double chambered right ventricle (DCRV) is a congenital heart anomaly where the right ventricle is divided into two chambers. We describe, for the first time, an unusual combination of DCRV combined with some other congenital heart defects.

CASE PRESENTATION

A 1.2-year-old Golden Retriever was presented with lethargy, exercise intolerance and ascites. Physical examination revealed an irregularly irregular pulse and a grade V/VI, systolic, right cranial murmur. Electrocardiography revealed widened and splintered QRS complexes with a right bundle-branch block pattern. Radiography demonstrated right-sided cardiomegaly. Two-dimensional echocardiography identified a DCRV with tricuspid valve dysplasia. The patient died despite abdominocentesis and 4 days of oral pharmacotherapy, and necropsy revealed an anomalous fibromuscular structure that divided the right ventricle into two compartments. Another finding was tricuspid valve dysplasia with hypoplasia of the posterior and septal leaflets. The anterior leaflet was prominent, being part of the anomalous structure that divided the right ventricle. Necropsy also identified a perimembranous ventricular septal defect and mild subaortic stenosis. Histopathological examination of the fibromuscular band that separated the right ventricle identified longitudinally oriented layers of dense fibrous connective tissue and myocardial cells arranged in a plexiform pattern. The muscular component was well represented at the ventral area of the fibromuscular band, and was absent in the central zone. Superficially, the endocardium presented areas of nodular hyperplasia covering mainly the fibrous part of the abnormal structure. The nodules were sharply demarcated and were composed by loosely arranged connective tissue with myxoid appearance, covered by discrete hyperplastic endocardium.

CONCLUSIONS

Concomitant cardiac malformations involving DCRV, tricuspid valve dysplasia, perimembranous ventricular septal defect and mild subaortic stenosis have not been previously described in veterinary medicine, and are reported here for the first time. Moreover, this is the first report of a canine patient with tricuspid valve dysplasia (TVD) and DCRV where the anterior leaflet is part of an anomalous structure dividing the right ventricle (RV) into two separate compartments.

[Isolated double-chambered right ventricle (DCRV): a case study conducted at the National University Hospital CNHU-HKM in Cotonou, Benin]

Le ventricule droit à double chambre (VDDC) est une malformation cardiaque rare dans laquelle le ventricule droit est divisé en deux chambres par une bande musculaire anormale. Il est associé dans 80 à 90% à d'autres malformations. L'expression clinique est variée et dépend de l'importance de l'obstruction intraventriculaire. Nous rapportons l'observation d'une adolescente de 16 ans, présentant une forme isolée de VDDC révélée par des syncopes à répétition. Le diagnostic est fait par l'échocardiographie Döppler. La résection chirurgicale de la bande musculaire anormale a été faite avec succès.

A case of asymptomatic isolated double-chambered right ventricle in an adult man

Double-chambered right ventricle is a rare congenital heart disease. An anomalous muscle band divides the right ventricle into two cavities, causing a variable degree of obstruction. Most cases of double-chambered right ventricle are diagnosed and treated during childhood, whereas cases of initial presentation during adulthood are very rare. We report a case of asymptomatic isolated double-chambered right ventricle incidentally found in an adult man.

Characteristics of double-chambered right ventricle in adult patients

BACKGROUND/AIMS

This study evaluated the clinical features of double-chambered right ventricle (DCRV) in adults. Most cases of DCRV are diagnosed and treated during childhood. Consequently, very few reports include cases in which its clinical characteristics are evident in adults.

METHODS

We reviewed the clinical data for 10 adult patients (age > or = 18 years) with DCRV.

RESULTS

Electrocardiogram showed right ventricular hypertrophy in 3 DCRV patients. All cases were associated with ventricular septal defect (VSD; 7 for perimembranous, 2 for muscular outlet, and 1 for the subarterial type). Surgical correction was done for 7 DCRV patients all of whom survived operations. Their follow-up echocardiogram showed the pressure gradient in their right ventricle was significantly decreased from 69.4 +/- 17.2 mmHg preoperatively to 10.2 +/- 5.0 mmHg postoperatively (p < 0.05). In the short-term follow-up, there was no significant increase in the pressure gradient in the right ventricle.

CONCLUSIONS

There are lots of cases of DCRV that are not diagnosed accurately in adults. In our experience, all DCRV cases had VSD and surgical correction of these cases showed excellent results. Therefore, accurate diagnosis of DCRV is necessary so that DCRV is not overlooked and operations are enabled within an appropriate time.