Disorder - Persistent truncus arteriosus

Organ Systems Involved
Cardiovascular

Alternative disorders described within LIDA

Tetralogy of Fallot with pulmonary atresia; DiGeorge Syndrome; Velocardial facial

Presenting Signs

Persistent truncus arteriosus is a malformation of the heart, in which the septum (wall) that divides the common arterial vessel into an aorta and pulmonary vessels is missing. This results in a single large artery that arises from the base of the heart and supplies deoxygenated blood to three different heart compartments (systemic, pulmonary and coronary blood flows). The symptoms depend on how oxygenated blood is flowing compared to the deoxygenated blood flow. When vessel resistance is lower in the lung than resistance in the aortic vessel, blood flows towards the lung vessels, increasing the blood flow to the lung. When high pressure is present in the lung, deoxygenated blood from the right ventricle is pumped into the aorta. The low level of blood oxygen results in a blue colour to the gums (cyanotic mucous membranes). Affected cats may be less able to exercise than normal, have stunted growth, rapid, heavy breathing and blue mucous membranes after exercise or excitement. They are often smaller in size than their littermates. The heart is often enlarged on X-rays. The blood vessels of the lung and the aorta are often distended when seen on ultrasound. The heart defect can also cause abnormal heart sounds; this can be heard during stethoscope examination. Affected cats have a poor outlook and they usually do not have a long life span.

Cats at Risk

No age or sex predisposition. It is a congenital heart defect, any cat can be affected. No family predilection has been recorded.

Treatment

Medical

PubMed References
Persistent truncus arteriosus

Contributor
Jeffrey Chu