Ventricular septal defect is a congenital heart condition that:

In aventricular septal defect (VSD), blood shunts from theleft to the right ventricledue to higher systemic pressure. This leads toincreased pulmonary blood flow(left-to-right shunt), which can cause pulmonary overcirculation and heart failure if untreated.

“VSDs result in a left-to-right shunt that increases pulmonary circulation. This may cause pulmonary congestion, increased work of breathing, and failure to thrive in infants.”

(Referenced from CCRN Pediatric – Direct Care: Cardiovascular Congenital Defects)