Classification of CHD

•  CYANOTIC OR ACYANOTIC

•  ECG LVH, RVH, BiVH or normal •  Cxray pulm vascular markings – increased

or decreased or normal Practical classification using simple

investigations.

Acyanotic CHD

L to R Shunts - Ventricular septal defects - Atrial septal defects - Patent ductus arteriosus Obstructive lesions Coarctation of the aorta Aortic stenosis Pulmonary stenosis Bicuspid aortic valve Mitral valve prolapse

Tetralogy of Fallot Transposition of great arteries Tricuspid atresia Truncus arteriosus Total anomalous pulmonary venous return Hypoplastic left heart syndrome Pulmonary atresia

Cyanotic CHD

Left to Right Shunts Pathophysiology

In VSD and PDA size of shunt depends on: size of defect pulmonary vascular resistance Small defect presents great resistance to L-R shunt which does not depend on PVR. Large defect offers little resistance to shunt which depends on PVR. In ASD shunt depends on size of defect and compliance of right ventricle and PVR.

L to R shunts- Haemodynamics

Oxygenated blood flows across defect into R sided chamber / pulmonary artery -> pulmonary bed -> pulmonary veins -> L atrium. Overloaded chambers dilate and hypertrophy. Total blood volume increases.

Clinical effects of L to R Shunts

Small defects asymptomatic. Moderate and large defects: ECG and Cxray changes. Failure to thrive Congestive cardiac failure Pulmonary hypertension Infective endocarditis risk in small and large defects. Low risk in ASD.