Which heart defect is indicated by a large atrial septal defect and a single valve?

The presence of a large atrial septal defect (ASD) along with a single valve indicates a condition known as single ventricle physiology. In this scenario, the heart develops with only one functional ventricle instead of the usual two, which can lead to an ASD as part of the structural abnormalities present. This defect necessitates a compensatory mechanism for blood flow and can significantly impact how oxygenated and deoxygenated blood circulates in the body.

Single ventricle physiology typically involves various other anomalies, such as a single atrioventricular valve that serves both the left and right circulations. This is a common arrangement in specific congenital heart defects, where due to embryological development errors, the heart is formed in a way that lacks the normal two-ventricle configuration.

Understanding single ventricle physiology is critical in pediatric cardiovascular practice as it dictates complex management strategies and interventions to care for affected patients, including possible surgeries to create a more effective pathway for blood flow, often culminating in a series of staged surgical procedures throughout early childhood.