COH – PEDIATRIC SYNOPSIS Congenital Cardiac Diseases: Congenital heart diseases (CHDs) are structural heart defects present at birth. They can be categorized into cyanotic and acyanotic heart diseases. Below is a detailed list of major congenital cardiac diseases, including essential clinical information. 1. Cyanotic Congenital Heart Diseases (CCHD) These conditions cause low oxygen levels in the blood, leading to cyanosis (bluish discoloration of skin and mucosa). 1.1. Tetralogy of Fallot