Search

We present a case of a 12-year-old girl with severe cyanosis due to abnormal moderator band producing a hidden trabecular component of the right ventricle, mimicking isolated hypoplasia of the right ventricle. A marked hypoplasia was confirmed by echocardiography and catheterization. At operation an anomalously thickened moderator band obstructing the apical infundibulum was found. Repair consisted of a section of the moderator band and closure of the atrial septal defect. Postoperatively the right ventricle showed normal dimension and function.

Between 1983-1988 cross-sectional echocardiography was performed in 63 patients having an atrioventricular septal defect with common atrioventricular orifice. We excluded from this study all those patients with separate right and left orifices ("ostium primum" defects), those with isomerism of the right and left atrial appendages, those with univentricular atrioventricular connexions and those with discordant atrioventricular and ventriculo-arterial connexions. Parasternal long- and short-axis views, apical 4-chamber views and subcostal long-axis views were employed in all patients. In the last 26 cases, we also obtained the subcostal short-axis view. Nineteen patients showed ventricular dominance, with the right ventricle being dominant in 15. Ten patients had an associated defect in the oval fossa, while the atrial septum was partially or completely absent in the other 53. A ventricular septal defect was observed in all, but it was small in 10 and multiple in 2. Attachments of the superior and inferior bridging leaflets to the crest or the right side of the ventricular septum were seen in 32 cases. The inferior leaflet was hypoplastic in 19 patients. There was narrowing of the left ventricular outflow tract in 8 patients, and obstruction of the right ventricular outflow tract in 3. Abnormal attachment of the right portion of the common valvar orifice was present in 2 cases. A solitary papillary muscle supporting the left ventricular component of the common valve was seen in 6 cases producing a parachute-like arrangement. Our study shows that cross-sectional echocardiography is an excellent technique for the analysis of this anomaly.

We present a study using cross-sectional echocardiography in 39 patients (29 male and 10 female) with discrete subaortic stenosis. Five parameters were evaluated in the study: the morphology of the obstruction, the distance of the stenosis from the aortic valve, the type of insertion, the base of implantation, and any associated anomalies. The lesion could be divided into groups with either fibrous or fibromuscular shelves. In the group of 14 patients with fibrous shelves, the distances from the stenotic lesion to the aortic valve was less than 15% of the length of the left ventricle. The obstructive fibrous tissue was inserted on the septum and extended onto the aortic leaflet of the mitral valve (circumferential lesion) in 12 cases. The base of implantation was narrow in all 14 of them. In the 25 patients having fibromuscular lesions, the distance between obstruction and valve was greater than 18.4% of the length of the left ventricle. The insertion of the obstructive lesion was circumferential in 18 cases and its base of implantation was wide in 20 of the patients. Nineteen patients, 16 of whom had fibromuscular lesions, showed associated anomalies. Statistical analysis showed a good correlation between the type of stenosis and the base of implantation of the stenotic lesion (P less than 0.001) or associated anomalies (less than 0.01), but there was no distinction between the groups with regard to the type of insertion (less than 0.38). Twenty-five patients underwent surgical correction which was carried out between the ages of 4-14 years. Prosthetic valves (3 aortic and 1 mitral) were inserted in 4 patients.(ABSTRACT TRUNCATED AT 400 WORDS)