Congential Heart Diseases: Cyanotic Flashcards
What are the characteristics of cyanotic congenital heart defects?
- Around the mouth & lips, fingertips, toes
- All have right to left shunts
- Many CHD are ductus dependent
A. Neonate may not have sx’s until DA closes in the first few days of life
B. May not be diagnosed until after discharge
What are the cyanotic heart diseases?
- Tetralogy of Fallot: 7-10% of cases of CHD
- Pulmonary Atresia/IVS: 1-3% of all CHD
- Hypoplastic Left Heart Syndrome: 2-3% of all CHD
- Transposition of Great Vessels: about 3% of CHD
A. Dextro-TGA most common type
What are the 4 anomalies in the tetralogy of Fallot?
- Subaortic septal defect (VSD)
- Pulmonary stenosis
(RV outflow obstruction) - Overriding Aorta (dilated)
- Right ventricular hypertrophy (RVH)
What may be asst. with tetralogy of Fallot?
1. Down Syndrome A. Trisomy 21 B. 50% have a type of CHD 2. Alagille Syndrome A. Mutation in JAG1 3. DiGeorge & Velocardiofacial Syndromes A. Microdeletion syndrome (chromosome 22q11)
What ths pathophys of ToF?
- Largely dependent upon the degree of right ventricular outflow obstruction (Pulm Stenosis)
- Direction of blood flow across the VSD determined by the path of least resistance for blood flow
A. Predominate a left-to-right shunt
B. Patient acyanotic
C. Right-to-left shunt across the VSD
D. Large volume of desaturated blood entering the systemic circulation
E. Cyanosis and polycythemia
Define Tet spell or hypercyanotic spell
In the most dramatic situation, there can be near occlusion of the right ventricular outflow tract with profound cyanosis
What are the sxs of tof dependent on?
Clinical presentation depends upon the degree of pulmonary stenosis
More severe stenosis leads to greater reduction of pulmonary blood flow and increased cyanosis
What are the sxs of severe obstruction?
profound cyanosis
What are the sxs of moderate obstruction?
Heart murmur
What are the sxs of minimal obstruction?
Heart failure
What are the common sxs of ToF?
- Most children are symptomatic and cyanotic
- Right ventricular thrill
- Harsh systolic ejection murmur (SEM) along left mid to upper sternal border with radiation posteriorly
- Murmur may disappear during “tet” spells due to shunting of blood away from obstruction
What are the dx studies for ToF?
- ECHO
- CXR
- EKG
- Cardiac Cath
What are the results of ECHO in ToF?
Confirms Dx of four cardiac anomalies
What are the results of EKG in ToF?
RAE, RVH, R Axis Deviation
What are the results of CXR in ToF?
- Boot shaped heart
- Upturned apex
- Right aortic arch in 25% cases
What are the results of Cardiac cath in ToF?
Delineate degree of outflow obstruction
What is the tx for ToF?
- Intracardiac repair
2. Patch closure VSD and repair of pulmonary stenosis
How can tet spells be managed?
- Knee-chest position to ↑ systemic vascular resistance
A. Promotes movement of blood from right ventricle to pulmonary circulation rather than LV - Pharmacologic measures
A. Morphine, fluids, beta blockers
Describe pulmonary valve atresia
- Anatomic abnormalities:
A. Pulmonary valve is closed
-Complete obstruction to . RV outflow
B. Varying degrees of RV hypoplasia and tricuspid valve hypoplasia - Intact ventricular septum (PA/IVS)
What are the physiologica consequences of pulmonary atresia?
- Pulmonary valve does not open
- Pulmonary blood flow is dependent on PDA
A. Blood flow from aorta to pulmonary artery
B. PDA is crucial for survival in neonate
-Sole source of pulm blood supply
What are the sxs of pulmonary atresia?
1. Cyanotic A. newborn can usually be diagnosed w/IN hours or minutes after birth 2. Hypoxic on room air & on 100% oxygen 3. Mild tachypnea 4. Single 2nd heart sound (S2 not split)
What are teh CXR results in pulmonary atresia?
CXR
Cardiomegaly
Wha tsi the treatment for pulmonary atresia?
- Only source of pulmonary blood flow is apatent ductus arteriosus
- Stabilize neonate w/ prostaglandin E1 infusion to keep DA patent, then surgical repair
What is the prognosis if pulmonary atresia is unrepaired?
almost uniformly fatal disease
W/in 2 wks, approx 50% die & by 6 mos 85% will die
Describe hypoplastic left heart syndrome
- Underdeveloped left heart w/normally placed great vessels , AND hypoplasia of the ascending aorta and arch
A. Hypoplasia of LV including atresia, stenosis or hypoplasia of the aortic or mitral valve, or both valves
What can HLHS lead to?
LV unable to support systemic circulation
Can lead to cardiogenic shock, ventilatory insufficiency, and death
What is the initial tx for HLHS?
Initial treatment - stabilize neonate
Maintain patency of DA via prostaglandin E1 infusion
Need PDA and ASD initially to survive
Inter-atrial mixing of oxygenated and deoxygenated blood necessary to survive
What is the definitive tx for HLHS?
Long Term treatment is surgery
Staged repair or heart transplant
Describe transposition of the great arteries
Complete transposition of Aorta and PA
What is the pathophys of d-TGA?
- Deoxygenated blood from the right heart is pumped thru the aorta bypassing the lungs altogether
- Left heart pumps oxygenated blood continuously back into the lungs through the PA
- 2 separate “circular” (parallel) circulatory systems are created
What is simple d-TGA?
NO other heart defects
What is complex d-TGA?
Co-existing cardiac anomalies (Complex d-TGA) VSD 50% cases L ventricular outflow tract obstruction 25% cases
What are the sxs of d-TGA?
- Cyanosis
- Clubbing of the fingers or toes
- Poor feeding
- Shortness of breath
How is d-TGA diagnosed?
- Difficult to diagnose on fetal ultrasound
- Most cases diagnosed by clinical suspicion of cyanotic congenital heart Dz
- Dx confirmed by echocardiography
How is d-TGA treated?
1. Prostaglandin infusion A. Maintain open Ductus Arteriosus 2. Balloon Atrial Septostomy A. Cath lab or bedside 3. Anatomical surgical correction A. Arterial switch operation
