CONGENITAL HEART DISEASE (AB) Flashcards
3 cardiovascular structures unique to the fetus
Ductus venosus, Foramen ovale (located at the interatrial septum), Ductus arteriosus (if it stays open, it is called patent ductus arteriosus)
What happens when there is a disruption in the flow of blood within the heart chambers?
Congenital heart defects may occur.
What happens in tricuspid valve atresia?
Restricted blood flow to the right ventricle, leading to underdevelopment of the right ventricle and pulmonary artery.
Examples of right-sided cardiac lesions
Tricuspid valve atresia, hypoplastic right ventricle, pulmonary atresia.
Where does exchange of metabolites and oxygen occur in the fetus?
Placenta
What are the components of the umbilical cord?
Two arteries and one vein (AVA).
Pathway of oxygenated blood entering the fetus
Umbilical vein → liver (some) → ductus venosus → inferior vena cava (IVC) → right atrium (RA)
Why is blood shunted from the right atrium to the left atrium via the foramen ovale?
Because the right side of the heart has higher pressure than the left side in utero.
What is the main ventricle in intrauterine circulation?
Right ventricle
What happens after birth when the lungs expand?
Pulmonary vascular resistance decreases, blood flows to the lungs, and oxygen exchange occurs.
What happens to the ductus arteriosus and ductus venosus after birth?
They constrict due to increased oxygen levels.
What causes the physiological closure of the foramen ovale?
Increased blood flow to the left atrium after birth.
By what age is anatomical closure of the foramen ovale expected?
2 months of age
What is the first step in evaluating congenital heart disease (CHD)?
Thorough history taking and physical examination
Prevalence of symptomatic congenital heart disease in newborns
2-3 per 1000 live births
Most common cyanotic congenital heart disease
Tetralogy of Fallot
Most common complex congenital heart disease
Transposition of the great arteries
Genetic conditions associated with CHD
DiGeorge Syndrome (22q11.2 deletion), CATCH 22, Conotruncal defects (TOF, TA, DORV, VSDsubarterial), Brachial arch defects (COA, IAA, Right Aortic Arch)
Environmental factors linked to CHD
Maternal diabetes, maternal PKU, SLE, congenital rubella syndrome, maternal use of lithium, ethanol, warfarin, vitamin A derivatives, and AEDs.
Common L→R shunt lesions
Ventricular septal defect (VSD), Atrial septal defect (ASD), Patent ductus arteriosus (PDA), Coarctation of aorta
Key clinical features of cyanotic congenital heart disease
Squatting, cyanosis, clubbing, syncope
What diagnostic tool helps assess pulmonary blood flow in CHD?
Chest X-ray
How does left ventricular hypertrophy (LVH) present on ECG?
Large R waves in left-sided leads (V5, V6, aVL, I) and deep S waves in right-sided leads (V1, V2).
How does right ventricular hypertrophy (RVH) present on ECG?
Large R waves in right-sided leads (V1-V3) and deep S waves in left-sided leads.