Congenital Heart Defects
Patent Ductus Arteriosis
Tetralogy of Fallot
Transportations of the Great Vessels
Coarctation of the Aorta
Low cardiac output
S/S
Treatment
When commonly noticed:
What is it
Shunts blood from pulmonary arteries to aorta through combined arteries and a bridge between them. Sends oxygenated blood back to pulmonary arteries. Think of pressures, moving from high to low pressure.
Shock
The hole is commonly closed in full-term infants within several weeks after birth
8-10% of all Congenital heart defects
Can cause secondary HTN in children
Prevalence
5-10% of infants with Congenital Heart Disease (CHD)
More common in preterm infants
Pathophysiology
Failure of the PDA to close results in persistent opennes of the ductus arteriosus. The shunting increases over time as PVR(peripheral vascular resistance) falls and SVR(systemic) does not, the aortic blood begins to enter the pulmonary aortic artery.
Increases risk of ventricular hypertrophy
The hemodynamic effect is increased pulmonary blood flow, resulting in increased pulmonary venous return to the LA and LV with increased workload on the left side of the heart
The increased workload is caused by increased pulmonary venous return to the LA and, potentially, an increase in right ventricular pressure if pulmonary vascular changes occur in response to the increased blood flow, leading to an increase in pulmonary vascular pressure.
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Coarctation of the aorta (COA) is a narrowing of the lumen of the aorta that impedes blood flow. (pg. 1115)
Continuous machinery-like murmur (heard best at upper left sternum border)
Significant PDA: bounding pulse
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COA is almost always in a juxtaductal position,
although it can occur anywhere between the origin of the aortic arch and the bifurcation of the aorta in the lower abdomen.
(pg, 1115)
Active precordium (chest moves too much over heart)
Thrill on chest palpitation (vibration)
S/S of pulmonary circulation
Infants with small PDA usually remain asymptomatic
Exams to test PDA
Echocardiography
Auscultation for continuous "machine-like" sounds
Mixed Lesions
Premature infants who develop respiratory distress are initially given indomethacin or ibuprofen (both prostaglandin inhibitors) to close the duct.
Caused by blood flow in both directions
Many specialists perform transcatheter closure of the PDA during cardiac catheterization
Causes either cyanotic and cyanotic conditions
thoracoscopic surgery
Lesions decreasing pulmonary blood flow
Cyanotic right to left shunt
Blood flows from the left side of the heart to the right