Congenital Heart Disease Most common type of heart disease among children a) ~ 1% of live births b) most causes unknown i) ~ 10% genetic - e.g., trisomy 21 (Down syndrome) - congenital defect in parent or sibling is greatest risk factor

Types: a) L to R shunt b) R to L shunt c) obstructions 1.- L to R shunts a) ASD, VSD, PDA i)  pulmonary blood flow (ASD) - NO cyanosis b)  RV pressures and Vol. (VSD,PDA) i) hypertrophy ii)  PVR (vasoconstriction) - to prevent edema

c) Over time PVR  to that of SVR i) reverses shunt (cyanosis) 2.- R to L shunt a)  pulmonary blood flow i) Cyanosis “blueness” of skin b) examples: i) tetralogy of Fallot ii) great vessel transposition iii) truncus arteriosus iv) tricuspid atresia v) anomalous pulmonary venous connection

c) long standing cyanosis is. associated with “clubbing” of the c) long standing cyanosis is associated with “clubbing” of the tips of the fingers and toes

3.- Obstructions (of flow) a) coarctation of the aorta b) valvular stenosis i) aortic ii) pulmonary c) complete obstruction is called “Atresia”

Left to Right Shunts Most common: a) VSD, ASD, PDA and AVSD

i) VSD most common - close spontaneously (50%) ii) ASD usually not symptomatic before 30 yrs

iii) DA remains open after birth - ~ 90% occur as isolated anomaly - reversal of flow with  PVR causes cyanosis - PGE will maintain DA cardiac defects such as obstructive disease iv) complete atrioventricular canal defect - all 4 chambers freely communicate (Down syndrome)

Right to Left Shunts Tetralogy of Fallot a) Most common form of cyanotic congenital heart disease Defects: a) VSD b) Pulmonary artery stenosis i) determines clinical outcome c) aorta that overrides VSD d) RV hypertrophy

   

Clinical Presentation: a) The onset and degree of cyanosis depends on: i) severity of the pulmonary obstruction ii) the size of the shunt. b) Cyanosis is usually not seen until 3- 6 months of age. c) The cyanosis is due to right ventricle outflow obstruction causing unoxygenated blood through the VSD. Tetralogy of Fallot (TOF) Michael P. D'Alessandro, M.D. Peer Review Status: Internally Peer Reviewed

Transposition of the Great Arteries (TGA) a) aorta arises from RV i) is anterior and to the right of the pulmonary artery b) pulmonary artery arises from LV c) total separation of pulmonary and systemic circulations i) need a shunt to survive following birth - VSD  stable shunt

unstable shunt (close quickly after birth)  need surgery - PDA, foramen ovale  unstable shunt (close quickly after birth)  need surgery the aorta originates from the right ventricle, so most of the blood returning to the heart from the body is pumped back out without first going to the lungs. the pulmonary artery originates from the left ventricle, so that most of the blood returning from the lungs goes back to the lungs again

Truncus Arteriosus Failure of separation into aorta and pulmonary artery a) results in single great artery i) receives blood from both ventricles - early systemic cyanosis b) accompanying VSD c)  pulmonary blood flow i) danger of irreversible pulmonary hypertension

Tricuspid Atresia Clinical Presentation: a) Cyanosis is almost always present at birth and is progressive. b) Etiology/Pathophysiology: i) Due to absence of the tricuspid valve. This leads to an interatrial right to left shunt, usually through a patent foramen ovale.

Total Anomalous Pulmonary Venous Connection (TAPVC) No pulmonary veins directly join LA a) drain into left innominate vein or coronary sinus b) PV drain into RA ASD or foramen ovale always present a) allows PV blood to enter LA b) R to L shunt Volume and pressure hypertrophy of RV

Obsttructive Congenital Anomalies Coarctation of the Aorta Narrowing Males 2:1 vs. female a) females with Turners frequently have coarctation 2 types: a) infantile (with PDA; poor outcome) i) prior to PDA - symptoms early in life - cyanosis of lower body

b) adult (without PDA) i) most children asymptomatic until late in life ii) hypertension in upper extremities iii) hypotension in lower extremities LV hypertrophy