Atrial septal defect - Erler Zimmer

Atrial septal defect - Erler Zimmer

Clinical History

A 10-year-old girl with a known congenital heart condition was admitted for surgical repair due to recent-onset cyanosis and cardiac failure. On examination, she presented with breathlessness, a blood pressure of 105/60 mm/Hg, and a pulse rate of 140/min. A loud heart murmur was detected in the fourth left intercostal space adjacent to the sternum. The jugular venous pressure was elevated, and bilateral pulmonary basal crepitations were observed, but there was no peripheral edema. Despite successful repair of the defect during the operation, the patient experienced sudden post-operative deterioration of unknown cause, leading to her demise.

Pathology

The heart, viewed from the left side, reveals an opened left atrium displaying a large ovoid defect measuring 3.5 cm in greatest diameter in the inter-atrial septum. Only a small postero-inferior crescentic rim of the septum remains. The left ventricle is small, while the right ventricle is hypertrophied, as demonstrated by the cutaway of the right postero-lateral wall. The pulmonary artery, enlarged significantly, is visible to the left of the atrial cavities. Above the cut end of the pulmonary artery, the smaller vessel is the aortic arch. The cut edge of a lumen, 8 mm in diameter immediately below the cut end of the pulmonary artery, represents the left auricular appendage.

Additional Details

Atrial septal defects are typically asymptomatic in early life, even when large, with symptoms often manifesting in adulthood. Symptoms arise due to the reversal of the initial left-to-right shunt, leading to increased right ventricular hypertrophy and pulmonary hypertension. The subsequent right-to-left shunt is associated with cyanosis, dyspnea, and ultimately congestive cardiac failure.

Various types of atrial septal defects include:
Secundum - Most common, occurring in the middle of the atrial septum.
Primum - Located in the lower part of the atrial septum, often coexisting with other congenital heart problems.
Sinus venosus - Rare, typically found in the upper part of the atrial septum and associated with other congenital heart issues.
Coronary sinus - Rare, involving the missing part of the wall between the coronary sinus and the left atrium.
The cause of all atrial septal defects is not known, but some cases appear familial or associated with genetic problems like Trisomy 21 (Down’s syndrome). Certain conditions during pregnancy, such as infections, drug use, or exposure to harmful substances, may increase the risk of congenital heart defects.