Obligatory right to left shunt at the atrial level

Obligatory right to left shunt at the atrial level
Short Notes
Abstract: Obligatory right to left shunt at the atrial level occurs in tricuspid atresia, pulmonary atresia with intact interventricular septum and total anomalous pulmonary venous connection.
Obligatory right to left shunt at the atrial level means that the right to left shunt is mandated by the physiology in such a way that postnatal survival is not possible without that shunt.
Tricuspid atresia
The obligatory right to left shunt at atrial level is needed in tricuspid atresia because there is no other outlet for the right atrium. Blood returning to the right atrium from the vena cavae and coronary sinus reach the left atrium through an atrial septal defect. This blood passes through the left ventricle and can reach the right ventricle if there is an associated ventricular septal defect. In the absence of ventricular septal defect, the pulmonary blood flow is provided by a patent ductus arteriosus.
Pulmonary atresia with intact interventricular septum
In pulmonary atresia with intact ventricular septum, there is an obligatory right to left shunt at the atrial level because right ventricle has no outflow. Right ventricular cavity can either be diminutive or sizable with significant tricuspid regurgitation. Pulmonary blood flow is through a patent ductus arteriosus.
Total anomalous pulmonary venous connection
When all the pulmonary veins drain to the right side of the heart – either through a supra cardiac, ...

Source: Cardiophile MD - January 11, 2015 Category: Cardiology Authors: Prof. Dr. Johnson Francis, MD, DM, FACC, FRCP Edin, FRCP London Tags: General Cardiology obligatory right to left shunt at the atrial level TAPVC tricuspid atresia Source Type: blogs