Single Ventricle Heart Defect: Causes and Overview

Single ventricle heart defect is a relatively complex congenital condition, and its exact cause remains unclear. During weeks 3 to 5 of pregnancy, the heart's atrioventricular canal begins to develop. In cases of single ventricle malformation, the endocardial cushions—which play a key role in forming the ventricular septum—fail to develop properly. This results in the formation of a single functional ventricle instead of two separate chambers.

Types and Medical Implications

There are different types of single ventricle defects, often categorized based on blood pressure dynamics. In low-pressure cases, patients may survive with surgical interventions that help manage heart function. However, in high-pressure variations, a procedure known as pulmonary artery banding may be required to prevent excessive pressure from damaging the lungs.

Long-Term Prognosis and Treatment Challenges

Despite medical advancements, long-term outcomes for individuals with single ventricle defects can be limited. While a series of surgeries—such as the Fontan procedure—can improve quality of life, life expectancy often remains constrained, with many patients not living beyond their 40s or 50s.

Prenatal Diagnosis and Ethical Considerations

Due to the complexity and long-term health risks associated with this condition, prenatal screening plays a crucial role. When single ventricle defects are diagnosed during fetal development, medical professionals often advise parents to consider termination, in line with principles of reproductive health and informed decision-making. This recommendation is based on the significant medical challenges and reduced life expectancy associated with the condition.