Double inlet left ventricle

Double Inlet Left Ventricle (DILV) is a rare congenital heart defect characterized by both atria (the two upper chambers of the heart) connecting to the same ventricle. Typically, the heart has four chambers: two atria and two ventricles. In DILV, the right ventricle is underdeveloped, and the left ventricle receives blood from both atria, leading to a single functional pumping chamber. This condition is part of a group of defects known as single ventricle defects.

Etiology

The exact cause of DILV is unknown, but it is believed to involve genetic and environmental factors. It occurs early in fetal development when the heart is forming. Some genetic syndromes and maternal conditions have been associated with an increased risk of congenital heart defects, including DILV.

Pathophysiology

In a normal heart, the right atrium receives deoxygenated blood from the body and pumps it into the right ventricle, which then sends it to the lungs to be oxygenated. The left atrium receives oxygenated blood from the lungs and pumps it into the left ventricle, which then distributes it to the rest of the body. In DILV, the left ventricle performs the function of pumping both the oxygenated and deoxygenated blood, leading to mixing of blood and inefficient circulation.

Clinical Presentation

Symptoms of DILV may vary depending on the presence and severity of associated defects, such as pulmonary stenosis or transposition of the great arteries. Common symptoms include cyanosis (a bluish tint to the skin, lips, and nails), difficulty breathing, poor feeding, and failure to thrive.

Diagnosis

Diagnosis of DILV is typically made through echocardiography, which provides detailed images of the heart's structure and function. Other diagnostic tests may include electrocardiogram (ECG), chest X-ray, and cardiac MRI.

Treatment

Treatment for DILV often involves multiple surgeries performed in stages. The goal is to improve the heart's function and blood flow, which may involve creating a pathway for the blood to flow more effectively between the heart and lungs. The most common surgical approach is the staged Fontan procedure, which is completed in three stages: the Norwood procedure, the Glenn procedure, and the Fontan completion.

Prognosis

The prognosis for individuals with DILV varies. Advances in surgical techniques and postoperative care have significantly improved outcomes, allowing many patients to lead active lives. However, long-term complications can include heart rhythm problems, heart failure, and the need for heart transplantation.

See Also

• Congenital Heart Defect
• Hypoplastic Left Heart Syndrome
• Fontan Procedure