Persistant Truncus Arteriosus

Truncus arteriosus  is a rare heart defect that’s present at birth (congenital) also known as Common arterial trunk. If your baby has truncus arteriosus, it means that one large blood vessel leads out of the heart. Normally, there are two separate vessels coming out of the heart.In addition, the two lower chambers of the heart are missing a portion of the wall that divides them. As a result of truncus arteriosus, oxygen-poor blood that should go to the lungs and oxygen-rich blood that should go to the rest of the body are mixed together.

Types of Persistant Truncus Arteriosus

The most well-known classification was the fourfold system developed by Collett and Edwards in 1949.Collett/Edwards Types I, II, and III are distinguished by the branching pattern of the pulmonary arteries:

• Type I: truncus -> one pulmonary artery -> two lateral pulmonary arteries
• Type II: truncus -> two posterior/posterolateral pulmonary arteries
• Type III: truncus -> two lateral pulmonary arteries

The “Type IV” proposed in 1949 is no longer considered a form of PTA by most modern sources.

Causes of Truncus Arteriosus

Truncus arteriosus occurs during fetal growth when your baby’s heart is developing and is, therefore, present at birth (congenital). In most cases the cause is unknown.

Symptoms of Truncus Arteriosus

a) With large pulmonary arteries

Symptoms in early infancy i.e. CHF, respiratory infections

Dyphonea, stunted growth

b) With small pulmonary arteries

Cyanosis

Improved Longevity

Physical Examination for Truncus Arteriosus

Palpable S₂

S₂  single, no splitting, very loud

Harsh loud systolic ejection murmur in 3^rd / 4^th left intercostals space radiating upwards and to right

Early diastolic murmur of truncal valve regurgitation

Mitral diastolic flow murmur.

ECG Findings

Enlargement of all 4 chambers.

Treatment for Truncus Arteriosus

Closure of VSD which is usually associated.

Replacement of truncal valve

Conduit from RV to pulmonary artery.