Persistent truncus arteriosus

[Jason Yan]

Persistent truncus arteriosus is a birth defect where a single, large blood vessel exits the heart, instead of a separate pulmonary artery and aorta. Deoxygenated blood from the right side of the heart and oxygenated blood from the left side of the heart both enter this single large vessel (the truncus arteriosus) and a mixture of oxygenated and deoxygenated blood then flows to the body and lungs.

Symptoms include a bluish coloration of the skin (cyanosis) and symptoms of heart failure, including shortness of breath, poor feeding, sweating, and rapid breathing.
Diagnosis is by echocardiography.
Medical treatment for heart failure is typically followed by early surgical repair.

(See also Overview of Heart Defects.)
When the heart and blood vessels develop in the fetus, at first there is only one large tube, called the truncus, leaving the heart. Normally, the truncus divides into two blood vessels, the pulmonary artery and the aorta (see also Normal Fetal Circulation). Sometimes the truncus does not divide and persists during fetal development and after birth. There is one valve, the truncal valve, leading into this one artery, rather than separate aortic and pulmonic valves.
Persistent truncus arteriosus accounts for 1 to 2% of birth defects of the heart. Nearly all children with persistent truncus arteriosus also have a ventricular septal defect. Other problems that can be associated include a tight or leaky truncal valve, an interrupted aortic arch, a patent ductus arteriosus, an atrial septal defect, and DiGeorge syndrome.