A ventricular septal defect occurring on its own is a congenital defect of the interventricular septum of the heart causing varying degrees of increased pulmonary blood flow and associated clinical symptoms. It may also occur in association with obstruction in the right ventricle resulting in diminished pulmonary blood flow. Very little is documented about the incidence of ventricular septal defects in South African children.
The aim of this study was to briefly review the embryology and consider the normal anatomy of the interventricular septum. In addition, the clinical and surgical notes of all children that underwent surgical repair of ventricular septal defects (these included isolated ventricular septal defects, those with multiple ventricular septal defects, as well as those associated with tetralogy of Fallot and double chambered right ventricle) referred to the paediatric cardiothoracic unit at the Charlotte Maxeke Academic Hospital, from the Paediatric Cardiology units at the Charlotte Maxeke Academic Hospital, Chris Hani Baragwanath Academic Hospital and the Rahima Moosa Hospitals between 2001 and 2004, were analysed for the position, number of and size of ventricular septal defects.
For this purpose, 11 cadaveric neonatal hearts were dissected while seven post-mortem specimens of the heart, four with isolated ventricular septal defects and three with tetralogy of Fallot were analysed. In addition, 50 cases of isolated ventricular septal defects, 42 cases with tetralogy of Fallot and eight cases with double chambered right ventricle were retrospectively reviewed.
The membranous and the muscular septum made up the largest components of the interventricular septum in the normal neonatal hearts. A perimembranous ventricular septal defect was the most common type of defect diagnosed in these patients (the majority of the
patients were Black children), 78% of cases with a single isolated ventricular septal defect, 90% in patients with tetralogy of Fallot, and 75% in the group with double chambered right ventricle. The average sizes of all perimembranous defects (from the echocardiogram) were classified as small, moderate or large. An additional interesting finding was prolapse of the right coronary cusp of the aortic valve into the isolated ventricular septal defect and occurred in 22% (11 out of 50) of patients. Aortic regurgitation occurred in association with prolapse of the right coronary cusp in 54.5% (5 out of 11) of cases. This prevalence in black patients is much higher than has been documented in White or Japanese children.
Non-compaction of the left ventricle was seen in one post-mortem specimen in association with a perimembranous ventricular septal defect and dilated cardiomyopathy. This recently described abnormality is alluded to in the discussion.
Attention is drawn to the abnormality known as double chambered right ventricle, where the size of the ventricular septal defect is variable and where the site of obstruction in the right ventricle is caused by muscle bundles lower than that seen in tetralogy of Fallot.
Knowledge of ventricular septal defects found in South African children will help in the assessment and care of these patients with one of the most common congenital cardiac malformations.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/12652 |
| Date | 11 April 2013 |
| Creators | Osman, Mohseena |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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