Cardio Flashcards
(23 cards)
In utero - blood to head and upper extremities
Aorta
In utero - blood to organs and lower extremities
Descending Aorta
Changes when baby is born…
(1) Foramen ovale closes - allows blood to move from Right Atrium to Left Atrium
(2) Lungs expand
(3) PDA will close - in utero, connects aorta and pulmonary artery
(4) Ductus Arterioles closes - in utero, allows blood that escapes the right ventricle to bypass the pulmonary circulation. “Bridge from RV to aorta”
When do heart & great vessels develop?
During the first 3-8 weeks of gestation (in womb)
Neonate heart sounds…
Higher pitched, of greater intensity, and very fast!!
How do neonates & infants maintain cardiac output?
By increasing HR… They CANNOT increase stroke volume
What does their myocardial muscle need?
Calcium, Glucose, and Volume
Mothers with which conditions are at greater risk for having children with congenital defects?
Type 1 DM
Lupus
Factors that can impact a baby’s heart –> during pregnancy, the first semesters most important because that is when the heart forms
(1) Infection
(2) Alcohol
(3) Heroine - and other illicit drugs
(4) Prescription drugs
Infection - impact on baby (occur when mother gets these infections DURING her pregnancy)
(1) Cytomegalovirus: a late occurring sign is hearing loss, small # develop vision impairment as well. Can cause mono in young children.
(2) Fifth Disease: people who are pregnant can get Hydrops Fatalis –> an anemic crisis that can result in fetal demise.
(3) Cossack B - can cause congenital heart disease
(4) Herpes
Prescription Drugs that impact neonates
(1) Dilantin: an anti-epileptic drug (anticonvulsant). It works by slowing down impulses in the brain that cause seizures… in utero, increases a baby’s risk for congenital health defects.
(2) Amphetamines: CNS stimulant that is used in the treatment of ADHD
Vital Signs
Take HR and RR first (while baby is still calm)
Presence of thrill…
Means something is wrong with the valves
Heart Murmurs
Distinct swishing sounds that occur in addition to normal heart sounds. Make sure to record: location / time (in cycle) / intensity / loudness (graded over 6) –> 4+ are accompanied by a thrill.
Incidence of congenital defects
5-8 / 1,000 births
CHD major cause of death in first year of life
Most common is VSD - a heart defect due to an abnormal connection between the lower chambers of the heart (ventricles)
Hemodynamics
(1) Blood flows from area of higher pressure to low pressure & takes the path of least resistance [in a “normal” heart, the left side has a higher pressure]
(2) Pressure on the left side is greater than pressure on the right side –> OR, Pressure on the right side is Less than Left side
(3) Resistance in pulmonary artery* is less than systemic circulation. [*Pulmonary artery: carries blood from the right ventricle of the heart to the –> lungs for oxygenation].
(4) Pressure in pulmonary artery is less than the pressure in the aorta
Saturations
(1) Blood returning from great veins have the lowest O2 saturations
(2) Blood returning from lungs to pulmonary veins* is fully saturated [*The pulmonary veins receive oxygenated blood from the lungs and drain into the left atrium of the heart].
(3) Normally saturated blood circulates separately from desaturated. Mixing of blood (between right and left prior to going out) –> causes children to be cyanotic.
Hemodynamic Classification
(1) Increased pulmonary blood flow
(2) Obstruction to blood flow out of the heart
(3) Decreased pulmonary blood flow
(4) Mixed blood flow
Defects with INCREASED pulmonary blood flow
(1) Atrial Septal Defect (ASD) –> Left to Right shunting. Moving to area of lower pressure: “taking path of least resistance.” // Right Atrium and Ventricle enlargement (right side is not used to the pressure the blood is coming across at.
(2) Ventricular Septal Defect - MOST COMMON
- Opening between right & left ventricle
- Increase in pulmonary blood flow: Left blood going to Right side
- Increased pressure in the right ventricle. Can lead to hypertrophy
(3) AV Canal (Most common with Down Syndrome)
“just a big hole in the middle of the heart”
- Incomplete closure of endocardial cushions
- Low ASD continuous with high VSD
- Defects in mitral & tricuspid valve
- Blood flow between all 4 chambers of the heart
- Most common defect in Down’s symnndrome
(4) Patent Dustus Arteriosis (PDA) - Pressure in the aorta is greater than the pulmonary artery, so there may be some back flow into the lungs. [Medical Management: Indomethacin; prostaglandin inhibitor can help to close PDA
Eisenmenger Syndrome
Over a prolonged period of time, you have blood going from the left TO –> the right side of the heart (and then out into the lungs. The lungs were not set up to have that much blood flow under that much pressure, so children can develop secondary pulmonary hypertension.
Pulmonary hypertension: vascular resistance that develops because of the increased blood flow under high pressure. Causes damage to the muscle walls of the pulmonary arterials. Causes them to hypertrophy and develop resistance to blood flow.
“Back flow into the RV” - pressure from this back flow gets higher and higher. The right side of the heart will have a higher pressure because of the pulmonary hypertension.
Can get so bad, that the pressure from the right flows back into the left side - and the LV pumps de-oxygenated blood into circulation.
Obstruction to blood flow out of the heart
(1) Coarctation of the Aorta
(2) Aortic Stenosis
(3) Pulmonic Stenosis
Defects that decrease pulmonary blood
(1) Tetrology of Fallot (TOF)
(2) Tricuspid Atresia
Mixed Defects
(1) Transportation of the Great Vessels
(2) Hypoplastic Left Heart
