Following birth, the newborn's independent circulatory system is established. If there is an abnormal opening between the chambers in the heart, which cardiac defect may occur

ventricular septal defect

Explanation:

The ventricular septal defect is a very common defect in the septum. It is characterised by a hole or defect that divides the two sides of the heart hence causing communication between the ventricular cavities.

answer; more than 80% percent of adults;