Pathology: Congenital Heart Defects Flashcards
Right to left shunts result in
Cyanosis (hypoxemia)
Left to right shunts result in
Acyanosis (pulmonary congestion)
4 specific defects in tetralogy of fallot
VSD
Overriding aorta
Pulmonary artery stenosis
R ventricular hypertrophy
How is blood shunted in tetralogy of fallot?
R ventricle -> large VSD -> overriding aorta
TOF: what causes profound cyanosis?
Closing of PDA
How does TOF appear on CXR?
Boot-shaped
What causes “tet” spells
Coughing, crying, BM
What confirms dx of TOF?
Echo
Treatment/management of TOF
Supportive care/O2 prn
Prostaglandin E1
Surgery
What do prostaglandins do
Maintain PDA
Anatomical changes in transposition of great vessels (TGV)
Reversal of the origin of the aorta and the pulmonary artery, R ventricle -> aorta and L ventricle -> pulmonary artery
TGV: venous and arterial blood mixes through
ASD
VSD
PDA
TGV: when does cyanosis and hypoxia occur?
During first week of life as PDA closes
TGV: CXR
Egg-shaped
TGV: confirmation
Echo
TGV: treatment
Prostaglandins
Supportive care, O2 prn (decrease FiO2 if baby gets worse)
Balloon arterial septostomy (rashkind procedure) to create shunt for mixing
Surgery
What is coarctation of the aorta?
Severe narrowing of the aorta, causing decreased blood flow through aorta
Preductal coarctation of aorta
Narrowing occurs before PDA, results in R to L shunt
Postductal coarctation of aorta
Narrowing occurs after PDA, results in L to R shunt
Why is measuring BP in all four extremities when coarctation of aorta is suspected?
BP is higher in upper extremities
Coarctation of aorta: treatment
Supportive care with digitalis for heart failure
Prostaglandins
Surgery for resection of coarctation
Anatomical changes in truncus arteriosus
Single common vessel for both the aorta and pulmonary artery over VSD
Blood flow in truncus arteriosus
Systemic and pulmonary circulations delivered through same ventricle
Truncus arteriosus treatment
Be conservative with oxygen admin to keep PVR high
Rule of fourties’
Pulmonary artery banding
VSD closure
Surgery
What is the rules of 40’s?
PaCO2: 40
PaO2: 40
SaO2: 75%
Balances systemic and pulmonary flow
Anatomical changes in hypoplastic left heart syndrome
Severely underdeveloped L ventricle with stenosis or atresia of mitral valve
Dependent upon right ventricle for blood supply to both circulations
Techniques to balance pulmonary and systemic vascular resistance in hypoplastic left heart syndrome
Withhold oxygen therapy, subambient O2 (17-20%)
Target SpO2: 70-80%
Rule of 40’s
Hypoplastic left heart syndrome: treatment
Prostaglandins
Subambient FiO2
Hypercarbic gas mixtures
Complex surgical repair
Total anomalous pulmonary venous return (TAPVR) anatomical changes
Pulmonary veins fail to connect to left atria, may connect to superior or inferior vena cava
TAPVR: what two things are crucial for survival?
ASD
PDA
TAPVR: CXR
Snowman shaped heart
TAPVR: treatment
Prostaglandins
Balloon septostomy (ASD)
Surgery
atrial septal defect: anatomical changes
Failure of the foremen ovale to close
Cause of R heart failure in ASD
Increased workload of R heart
ASD: presentation in newborn
Initially healthy, failure to thrive
Difficulty feeding
Turns blue after crying, feeding, burping, etc (increased intrathoracic pressure)
ASD: treatment
Surgery
Supportive oxygen prn
ventricular septal defect: anatomical changes
Opening in septum between ventricles (most common)
How are small VSDs treated?
Spontaneous
Oxygen
Diuretics
Digoxin
How are large VSDs treated?
Surgery to patch
pulmonary artery banding
Why does blood shunt from the aorta into the pulmonary circulation (PDA)
Left to right, if left heart pressures are higher than right heart pressures
How is a pt evaluated for a PDA?
Pre- and post-ductal studies (PaO2 10-15 higher in right hand vs left) (15% if SpO2)
How is a newborn with a PDA treated?
Indomethacin (indocin) or ibuprofen (prostaglandin inhibitors)
O2 therapy
Fluid restriction and diuretics
Surgery
Atrioventricular septal defect (ASVD) other terms
Atrial-ventricular canal or endocardial cushion defect
ASVD: anatomical changes
Absence of atrial and ventricular septum
ASVD results in
Intra-atrial and intra-ventricular shunting, and atrio-ventricular regurgitation
ASVD most common in
Trisomy 21 (down syndrome)
ASVD: treatment
Children without CHF: diuretics and digoxin
SpO2 75-90%
Careful oxygen administration
Surgery
ASVD: higher SpO2 and oxygen results in
Reduced PVR and increased pulmonary blood flow (bad)
