This document provides information on congenital heart disease, including definitions, classifications, and details on specific conditions. It defines congenital heart disease and notes its prevalence of about 1% of live births. It classifies heart defects into left-to-right shunt lesions, right to left shunt lesions, and obstructive lesions. Details are given on specific conditions including atrial septal defect, ventricular septal defect, and patent ductus arteriosus. For each, the document describes hemodynamics, clinical findings, diagnosis, and treatment. Echocardiography is highlighted as the primary diagnostic tool for congenital heart disease.