Congenital Heart Diseases

Congenital Heart Disease: A brief summary

Introduction

• Congenital heart disease is the structural malformation of the heart, or great vessels, present at birth.
• Major cause of death in the first year of life.
• Common type of heart anomalies are ventricular septal defect, pulmonary valve atresia/stenosis, tricuspid atresia, artrial septal defects, transposition of great artery, tetralogy of fallot etc.

Concept

• Incidence in children 6-8/1000 live birth
• About 2/3 of these manifests in neonatal period.
• Manifested in newborn period are severe.
• 1/3 dies in neonatal period, especially during the first week of life.

General scenario

• CHD is the most frequently occurring congenital disorder, responsible for 28% of all congenital birth defects.

• The birth prevalence of CHD is reported to be 8-12/1000 live birth.

• Children with CHD are also more likely to have extra-cardiac defects such as tracheoesophageal fistula, renal agenesis and diaphragmatic hernia.

Etiology of CHD

• 85 to 90 % of cases, unknown
• Heredity and consanguineous marriage most important etiology

Maternal Factors:

• Anti-seizure medications Eg:- benzodiazepines and lithium
• Drug abuse:- cocaine. Alcohol, thalidamide
• Maternal phenylketonuria
• uncontrolled IDDM: high levels of the hormone insulin
• rubella – 1st trimester of pregnancy/ first 8 to 10 weeks of pregnancy
• Exposure to radiation during first trimester
• Chromosome diorder:

5 to 8 % of all babies with CHD have a chromosomal abnormality

• Down syndrome,
• Trisomy 18(Edwards syndrome)
• Trisomy 13(Patau syndrome)
• Turner’s syndrome
• Cri-du-chat syndrome (a piece of chromsome 5 is missing which is characterized by intellectual disability and delayed development, small head, low birth weight and weak muscle tone in infant

Fetal Factors:- 

• Birth asphyxia (Reduced myocontractility), fetal hypoxia

Fetal circulation: Before birth

1. Blood flows from the placenta
2. IVC
3. RA
4. Through the FO
5. LA
6. LV
7. Ascending aorta
8. Head & upper extremities
9. Returns via the SVC

Types if Congenital Heart diseases

Acynotic

1. Ventricular Septal Defect (VSD)
2. Atrial Septal Defect (ASD)
3. Patent Ductus Arteriosus (PDA)
4. Coarction of aorta
5. Aortic stenosis
6. Pulmonic stenosis

Cynotic

Decrease pulmonry blood flow

1. Tetralogy of Fallot (TOF)
2. Tricuspid Atresia

Mixed

1. Transposition of the Great Arteries (TGA)
2. Truncus Arteriosus (TA)

Congenital Heart Defects

• Acyanotic

• • Pink Baby (L à R shunt)
• 
  
• • cause CHF and pulmonary hypertension.
• 
  
• • S/S:- RV enlargement, RV failure, respiratory distress.

They are not typically cyanotic

 
Examples:

• 
  
• Ø Ventricular Septal Defect (VSD)
• 
  
• Ø Atrial Septal Defect (ASD)
• 
  
• Ø Patent Ductus Arteriosus (PDA)
• 
  
• Ø Coarctation of aorta

Cyanotic

• Blue Baby (R à L shunt)
• Cause hypoxia and central cyanosis.

• S/S:- Cynosis

• Unoxygenated blood circulates in arteries Ú cyanosis
Examples:

• Tetralogy of Fallot (TOF)
• Transposition of the Great Arteries (TGA)
• Truncus Arteriosus (TA)
• Tricuspid Atresia