<prompt> The most common congenital cardiac lesion identified at bih isASDVSDPDACoarctation of Aoa  <response>: Ventricular Septal Defect VSD This is the most common congenital cardiac lesion identified at bih accounting for one-quaer of all CHD. VSD is a communication between the two ventricles. 90 are located in the membranous pa of the ventricular septum with variable extension into the muscular septum. Others are located in the muscular septum and can be multiple. Reference: Essential Paediatrics; O.P. Ghai; Page no: 414 