Congenital left atrial enlargement. A case report with special reference to myocardial fine structure

Congenital left atrial wall aneurysm in a patient with neurofibromatosis

A congenital intrapericardial aneurysmal dilatation of the left atrial wall was found in a 28 year old man who presented with atrial fibrillation after a syncopal event. The patient had cutaneous manifestations of neurofibromatosis. The diagnosis was made by cross sectional echocardiography and confirmed by angiocardiography. Surgical excision of the aneurysm resolved the symptoms.

Intrapericardial aneurysm of the left atrial appendage

A 24-year-old housewife with congenital aneurysm of the left atrial appendage underwent a successful operation for its removal. Operation, using cardiopulmonary bypass, is indicated in all patients with atrial aneurysm. The procedure has proved uniformly safe and successful.

Right atrial ultrastructure in congenital heart disease. I. Comparison of ventricular septal defect and endocardial cushion defect

Ultrastructural studies were performed on portions of the operatively resected right atrium from six patients with a ventricular septal defect and six patients with an endocardial cushion defect. The six patients with a ventricular septal defect had normal right atrial mean pressure and no evidence of right atrial volume overload. Ultrastructurally, the atrial muscle cells in these patients appeared normal and measured 6 to 12 mu in diameter. The six patients with an endocardial cushion defect had elevated right atrial mean pressure and evidence of right atrial volume overload. Ultrastructurally, the atrial muscle cells in these patients were generally larger than 12 mu in diameter. The cells were irregular and had multiple and occasionally widened intercalated discs. In addition, there were degenerative changes in two patients with markedly increased atrial pressure. These changes included extensive loss of contractile elements, aggregation of small irregular mitochondria and proliferation of tubules of the sarcoplasmic reticulum. The structural changes suggest that hypertrophy of the right atrium may be secondary to volume overload of the atrium, whereas degenerative changes may be secondary to increased right atrial pressure.