Congenital heart defects Flashcards
(23 cards)
Etiology
most heart anomalies arise during wk 3-8
Causes- (Trisomies 13 15 18 21, turners Syn 45 XO, Monogenic disorders, Environmental , idiopathic (90%)
Shunts
An abnormal communication between chambers or vessels, Can be structural or functional, right to left or left to right
Left to right shunts
Oxygenated blood flowing into right sided circulation (no cyanosis)
Increases blood flow beyond its designated capacity
Pulmonary HTN and Right ventricular hypertrophy
Increased Right sided pressure reverses the blood flow and it becomes a R to L shunt
L to right shunting anomalies cause late cyanosis
Pulmonary Vasculature
increased pulm blood flow (ASD)- well tolerated by pulmonary vessels
increased pulm blood pressure (VSD)- not well tolerated by pulmonary vessels
Plexogenic pulmonary HTN- (medial hypertrophy, intimal proliferation, Plexiform lesions irreversible damage, VSD>PDA»ASD
Anomalies causing L-R shunts
Atrial septal defects (ASD)
Ventricular Septal Defect (VSD)
Patent ductus arteriosus (PDA)
Atrioventricular septal defect (AVSD)
Atrial septal defects (ASD)
Definition- interatrial opening present thruought cardiac cycle
Location: Secundum (at fossa ovalis) 90%, Primium (adjacent to AV valves 5%), Sinus Venosus near SVC entrance (5%)
Can be asymptomatic, can allow paradoxical embolism–<10 % lean to pulmonary hypertension
Atrial septal defect vs patent foramen ovale
Atrial septal defects are rare, fenestrated or deficient fossa ovale, left to right shunting, potential pulmonary HTN and right sided failure
Patent foramen ovale: present in 1/3 of people small remnant opening, no shunting (back pressure closes) except in rare circumstances, paradoxical emboli, decompression sickness, migraines
ventricular septal defect
interventricular opening
90% at septum (membranous VSD)
Most common congenital heart Anomaly, usually associated with other anomalies ( only 30% in isolation)
Membranous VSD
defect is usually large, spontaneous closure by septal TV leaflet occurs in <10% of cases
requires surgical closure around 1 yrs of age
Muscular VSD
Defect usually small
spontaneous closure by fibrous adhesions
most dont need surgery
multi muscular VSDs= swiss cheese septum
patent ductus arteriosus
normal ductal closure (functional in 12 h, structural in 3 mo)
Delayed by prostaglandins E1 and E2, closes later in preemies and at high altitude
Classic physical exam finding- Harsh, continuous, machinery like murmur
Other features- usually seen in isolation (90%), necessary for survival in AV or PV atresia, others
atrioventricular septal defect
deficient AV septum, associated with MV and TV anomalies
2 types- partial : primum ASD and CLeft MV with Mr
Complete: AVSD and common AV Valve
Other features: Down syndrome 40% with complete AVS
Right- to left shunts
R-L shunts dump deoxygenated blood into the systemic left-sided circulation, decreasing pulmonary blood flow causing early cyanosis
Paradoxical emboli and decompression sickness can occur when clots or gas bubbles are not filtered by the lungs and pass directly into the systemic circulation
Symptoms include cyanosis digital clubbing, polycythemia
Tetrology of fallot
most common form of cyanotic congenital heart disease
Anteriosuperior displacement of the infundibulat septum leads to VSD, subpulmonary stenosis, overriding aorta, RV hypertrophy
clinical outcome depends on severity of subpulmonary stenosis
Heart can appear boot shaped due to right ventricular hypertrophy, R-L shunt doesnt damage lungs because subpulmonary stenosis restricts pulmonary blood flow
Pulmonary outlet does not grow with child so effects are worse with age, surgery requires
Transposition of the great arteries
Aorta arises from RV, pulmonary artery arises from LV
Sequelae: Aorta lies anterior and to the right of the pulmonary aa, separate pulmmonary and systemic circulations
r ventricular hypertrophy develops, Pulmonary hypertension develops unless pulmonary stenosis is present
2 types: intact ventricular septum (65%) unstabel and needs prompt surgical intervention, With VSD 35% stable
truncus arteriosus
origin of aorta and pulmonary artery from truncal artery
Most have large VSD
Etiology: developmental failure of separation of the embryologic truncus into the aorta and pulmonary artery
Clinical sequelae: mixing of blood, increased pulmonary blood flow and pulmonary HTN
Variations: patterns in PA origins, truncal valve cusps
Other features: Digeorge syndrome
Tricuspid atresia
complete occlusion of the tricuspid valve orifice
Results from unequal division of the AV canal - mitral valve is enlarged
Needs coexisiting ASD/PFO and VSD, Causes right ventricular hypoplasia, symptomatic with high mortality
total anomalous pulmonary venous return
pulmonary veins dont directly drain into left atrium, left atrial hypoplasia
They connect via left innominate vein or coronary sinus
ASD/PFO allows oxygenated blood to enter systemic circulation
Occurs when common pulmonary vein fails to develop or regress
Aortic coarctation
Constriction/ narrowing of aorta
2 types: Preductal/infantile (tubular hypoplasia with PDA)
Postductal adult- ridgelike infolding at ligament without PDA
Bicuspid AV (50%) , Preductal (lower body cyanosis, requires surg in neonatal period), Postductal (symptoms depend on degree of narrowing, surgically treatable HTN, Rib notching
Pulmonary stenosis
pulmonary valve obstruction due to hypoplasia, dysplasia, or abnormal number of cusps
Isolated PV stenosis: RV dilataion and hypertrophy, post stenotic injury to PA, may be asymptomatic until adulthood
PV atresia with intact VS: hypoplastic RV and TV, PDA needed to get blood to lungs
Aortic Stenosis
Aortic valve obstruction due to hypoplasia, dysplasia, or abnormal number of cusps
Isolated AV Stenosis (80%)- LV Hypertrophy and LA dilation AS may range from mild to critical , systolic murmur
Aortic valve atresia with intact VS ((hypoplastic mitral valve and leftventricle, dependent on PDA for Survival, requires staged surgical surgical correction
Epstein anomaly of tricuspid valve
Inferiorly displaced and adherent septal and posterior leaflets
Redundant anterior leaflet, dilated annulus with TR
Secondary effect (RV and RA dilatioation)
Arrhythmias including WPW, asymptomatic until adulthood)
Dextrocardia
Right sided heart
