title_Adult Congenital Heart Center

congenitally corrected transposition of the great vessels

This defect consists of ventricular conversion in conjunction with abnormal positioning of the aorta and pulmonary arteries. The direction of blood flow is normal but the anatomic right ventricle must function as the high pressure systemic ventricle, instead of the low pressure pulmonary ventricle.

The vast majority of patients with congenitally corrected transposition of the great vessels also have other associated defects, such as a ventricular septal defect and/or pulmonary stenosis. These other abnormalities typically determine the clinical course. Only rarely does this lesion occur without other cardiac abnormalities.

Patients who also have a large VSD require early surgical closure; those with severe pulmonary stenosis and a VSD may require VSD closure and placement of a homograft or conduit from the ventricle to the pulmonary artery. An occasional patient can have a well-balanced situation and may not require surgery for many years.

When congenitally corrected transposition of the great vessels occurs without other defects, the clinical course is often favorable. However, an occasional patient may develop premature failure of the right ventricle, a leak in the tricuspid valve, and congestive heart failure. Abnormalities of the conduction system can also occur and may require a permanent pacemaker.

The long term issues in adults include:

1. the function of the systemic right ventricle and the tricuspid valve,
2. AV conduction (electrical) abnormalities, and
3. an assessment of the conduit or homograft for those who have undergone this form of repair.