This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Acyanotic congenital hea diseases, Subject name: Pediatrics
In septum primum type of ASD overburden occurs in which chamber? 
Select and explain. 
A. RA + RV, B. LA + LV, C. RA + LA, D. LA
A: RA + RV
Answer: A: RA + RV 
Explanation: - In ASD (ostium primum as well as secundum) overload of Right atrium and right ventricle occurs due to left to right shunting of blood. - Left atrium & Left ventricle enlargement - VSD, PDA - Left atrium enlargement - Mitral stenosis