Transposition of Great Vessels

Transposition of great vessels (TGV) is a group of congenital heart defects involving an abnormal spatial arrangement of any of the great vessels: superior and/or inferior venae cavae, pulmonary artery, pulmonary veins, and aorta. Congenital heart diseases involving only the primary arteries (pulmonary artery and aorta) belong to a sub-group called transposition of the great arteries.

Characteristics of Transposition of Great Vessels

Aorta is anterior and to right of pulmonary artery, arising from right ventricle

Pulmonary artery arises from left ventricle

Males affected more than females

Cyanosis from birth

Dysponea

Congestive failure

Incompatible with life in absence of ASD, VSD, PDA

Diagnosis of Transposition of Great Vessels

Physical Examination

CHF and cyanosis

S2 (second heart sound) single and loud (anterior aorta close to chest – wall)

Nondiagnostic murmurs in 1/3

X-Ray Chest

Heart shape, egg on side, with narrow vascular pedicle

Pulmonary plethora

E.C.G.

RA and RV enlargement

Right axis deviation

Echo

Defines the relation of great arteries to ventricles and associated defects

Catheterisation in Transposition of Great Vessels

To Confirm the diagnosis

Systemic Pressure in RV

O₂ saturation pulmonary artery > aorta.

Variants in Transposition of Great Vessels

Transposed vessels can present a large variety of atriovenous, ventriculoarterial and/or arteriovenous discordance. The effects may range from a change in blood pressure to an interruption in circulation, depending on the nature and degree of the misplacement and which vessels are involved.
Although “transposed” literally means “swapped”, many types of Transposition of great vessels involve vessels that are in abnormal positions, while not actually being swapped with each other. The terms TGV and TGA are most commonly used in reference to dextro-TGA – in which the arteries are in swapped positions; however, both terms are also commonly used, though to a slightly lesser extent, in reference to levo-TGA – in which both the arteries and the ventricles are swapped; while other defects in this category are almost never referred to by either of these terms.

Dextro-Transposition of the great arteries

Normal heart anatomy compared to d-TGA

In dextro-Transposition of the great arteries (dextro-TGA) deoxygenated blood from the right heart is pumped immediately through the aorta and circulated to the body and the heart itself, bypassing the lungs altogether, while the left heart pumps oxygenated blood continuously back into the lungs through the pulmonary artery. In effect, two separate “circular” (parallel) circulatory systems are created. It is called a cyanotic congenital heart defect (CHD) because the newborn infant turns blue from lack of oxygen.

Levo-Transposition of the great arteries.

Levo-Transposition of the great arteries is an acyanotic heart defect in which the primary arteries are transposed, with the aorta anterior and to the left of the pulmonary artery, and the morphological left and right ventricles are also transposed.

Treatment for Transposition of Great Vessels

Balloon septostomy to improve mixing correction after wards with

         a) Mustard procedure

Atrial baffle resoutes flow to appropriate ventricles

         b) Rastelli Procedure

Ventricular baffle connects LV to aorta

Prosthetic conduit connects RV to PA

Associated Defects, PDA,VSD, ASD, Mitral valve anomalies.

Truncus (High VSD associated)

1. Sys.thrill, murmur at base

2. S₂ loud and single

3. Cardiomegaly gross with wide shadow