Cardiology Flashcards
How is the fetal blood oxygenated?
Fetal blood is oxygenated by placenta instead of lungs.
Fetal lung are currently collapsed at this time
What are the three structural differences in a fetal heart?
- Ductus venosus
- Foramen ovale
- Patent ductus arteriosus
Define
Cardiac output
volume of blood ejected by heart in 1 minute
What do neonates and infants depend on to maintain cardiac output?
Heart rate and rhythm
Do not have the capacity to ↑ stroke volume yet
Define
Preload
The amount to which the ventricles stretch to be filled during diastole.
volume of blood returning to the heart
Define
Afterload
Afterload is the pressure that the heart must work against to eject blood during systole
Hypertension is common adult reason for increased afterload.
Neonatal & infant myocardial muscle is less efficient & has fewer organized myocardial fibers, so it is very dependent on what three factors for adequate cardiac output.
- calcium
- glucose
- volume
What are the differences in heart sounds between a newborn and an adult?
Newborn heart sounds are higher pitched and greater intensity
What is the function of the ductus venosus?
carry oxygenated blood from the umbilical vein to the the IVC
- What is the function of foramen ovale during fetal circulation?
- Why is it needed?
- Shunts blood from the RA → LA during fetal circulation.
- Allows oxygenated blood to by pass the lung
decreases pressure on fetal heart needed to pump blood out
What three maternal conditions increase the risk of heart disease in infants?
- Type 1 Diabetes
- Lupus erythematosus
- PKU
What is the purpose of the four extremity BP in infants?
Assessing for differences in upper and lower extremity BP
Sign and symptom of?
Large differences in upper and lower extremity BP
Coarctation of the aorta
Narrowing of the aorta
Sign and symptom of?
If there is a > 2% difference in pre-ductal (hand) and postductal (foot) SpO2
Assessed 24 hours after being born
Right to left shunting
deoxygenated blood is going over to left side into systemic.
- Where would you find the PMI and apical impulse in child ≤ 7?
- How about child ≥ 8
- Fourth intercostal space
- Fifth intercostal space
Sign and symptom of?
Presence of a thrill
Can indicate valvular anomaly (heart murmurs)
How does blood flow in relation to pressure?
Blood flows from higher pressure to lower pressure
- Where is the pressure normally higher in the heart left or right side?
- When is it normally the opposite?
- Left side has higher pressure
- Right side during fetal circulation
What are the four hemodynamic classifications of congenital heart disease?
- Increased pulmonary blood flow
- Decrease pulmonary blood flow
- Obstruction to blood flow out of the heart
- Mixed blood flow
*Which direction does blow flow in ASD?
*what hemodynamic classification does it fall under?
atrial septal defect
*Hole in the atria septum that causes blood to shunt from LA → RA.
*increased pulmonary blow flow
Occurs due to left side having higher pressure
What symptoms can occur w/ ASD?
atrial septal defect
- Right side hypertrophy
- What direction does blood flow in VSD?
- What type of hemodynamic blood defect is it?
ventricular septal defect
- Hole in the ventricle septum that causes blood to shunt from LV → RV.
- Increased pulmonary blood flow
Occurs due to left side having higher pressure
What is the most common type of atrial septal defect?
Secundum
center of septum
Eisenmenger syndrome is seen in which heart defects?
- Untreated VSD
- Can occur in AV Canal
Define
Eisenmenger syndrome
- Increased blood flow to PA causes pulmonary HTN.
- RV pressure increases which causes deoxy blood to shunt to LV out into circulation.
What is the most common congential heart defect?
Ventricular Septic Defect (VSD)
What defects are associated with AV Canal Defect?
What hemodynamic classification does it fall under?
Atrioventricular
- Incomplete closure of atria and ventricle septum causing an ASD and VSD.
- Also, defects in both AV valves.
- ↑ pulmonary flow
AV canal defect is most common in which people?
Atrioventricular
People w/ down syndrome
- What direction does PDA defect cause blood to flow abnormally?
- What hemodynamic classification is this?
Patent Ductus Arteriosus
- Failure of the PDA to close, causing blood to shunt out of aorta → PA.
- Increased pulmonary blood flow
What is the purpose of Indomethacin?
Prostaglandin inhibitor
Closes the PDA (patent ductus arteriosus)
What are the four types of heart defects associated with increased pulmonary blood flow?
- Atrial septic defect (ASD)
- Ventricle septic defect (VSD)
- AV canal
- Patent Ductus Arteriosus (PDA)
What are the three types of obstructive defects?
- Coarctation of the Aorta (COA)
- Aortic stenosis
- Pulmonic stenosis
- What is occuring with COA?
- What hemodynamic classification is it?
coaractation of the aorta
- Localized narrowing near insertion of ductus arteriosus
- Obstructive blood flow
What is the expected difference in BP and pulses w/ COA?
coaractation of the aorta
Increase BP/pulse in head and upper extremities and decreased BP/pulse in trunk and lower extremities
Collateral circulation are capillaries that formed to increase blood flow to lower extremities is associated w/ which heart defect?
Coaractation of the aorta
COA
What causes the obstructive defect for Aortic Stenosis?
Narrowing or stricture of aortic valve.
Why does hypertrophy of the heart occur?
Heart muscle becomes thickened (thickening of the wall)
Persistant increased pressure required in the atrium or ventricle
Due to valve stenosis or increased blood flow in that atrium/ventricle
What S&S are expected to be seen w/ Aortic Stenosis
- Decreased CO
- LV hypertrophy
- Pulmonary vascular congestion*
Blood on left side backs up to the lungs due to stenosis
- What causes Pulmonic Stenosis?
- What type of hemodynamic classification is it?
- Narrowing of entrance to pulmonary artery
- Obstructive blood flow
What can occur w/ severe pulmonic stenosis?
- Blood backs up to RA and increased pressure causes foramen ovale to reopen.
- Deoxy blood shunts RA → Left (out into circulation)
What are the two types of defects with decreased pulmonary blood flow?
- Tetralogy of Fallot (TOF)*
- Tricuspid Atresia
due to pulmonic stenosis
What are the four defects of TOF that causes the decreased pulmonary blood flow?
Tetralogy of Fallot (TOF)
Four defects:
1. Overriding Aorta
2. VSD
3. pulmonic stenosis, and
4. RV hypertrophy.
- What is tricuspid atresia?
- Which hemodynamic classification is it?
- Tricuspid valve is missing
- Decreased pulmonary blood flow
- What occurs with w/ TGV?
- What hemodynamic classification is it?
Transposition of the Great Vessels
- Aorta connects to RV and PA connect w/ LV.
- Mixed defect
What are the two defects in Hypoplastic Left Heart that causes mixed defect?
- underdevelopment of LV and Aorta
- Aortic atresia
What causes the defect in truncus arteriosus?
When the Aorta and Pulmonary Artery fail to separate.
What causes Total Anomalous Pulmonary Venous Connection?
Pulmonary veins do not connect to LA.
- Which heart defect is associated w/ “TET” spells?
- What does it present as?
- TETralogy of Fallot (TOF)
- Suddenly developing cyanosis after crying or feeding, or when agitated.
deep blue skin, nails and lips
What interventions can be utilized for “TET” spells?
- Knee-chest position (reduces venous return of desat blood)
- Morphine IV push (calms child; relieves pulmonary stenosis spasms)
What is the purpose of prostaglandin E?
Keeps the PDA open after birth
Which heart defect is immediately incompatiable w/ life and needs surgery
Tricuspid Atresia
Which three heart defects are treated w/ Prostaglandin E?
Keeps PDA open
- Tricuspid Atresia
- Transposition of the Great Vessels (TGV)
- Hypoplastic Left Heart
What are the four causes of congestive heart failure?
- Volume overload from left to right shunting (VSD)
- Pressure overload from obstructive defects
- Decreased cardiac contractility (cardiomyopathy)
- High CO demand (sepsis, anemia)
Edema and/or Hepatomegaly is a symptom of right or left sided heart failure?
Right sided heart failure
Respiratory Distress and/or congestion is a symptom of right or left sided heart failure?
Left sided heart failure
(When the left side is not pumping correctly, blood backs up in the blood vessels of the lungs)
S&S retractions, grunting, wheezing, cough
Which heart defects need ASD or Foramen Ovale and PDA for palliative care until surgery?
- Tricuspid Atresia
- Transposition of Great Vessels
- Hypoplastic Left Heart
Which condition requires a permanent diet if diagnosed?
PKU
(low-protein diet)
Phenylketonuria
Exposure to Coxsackievirus A or B during pregnancy is associated myocarditis, encephalopathy, congenital heart defect?
Coxsackievirus B
What is the grading of murmurs?
- Very faint
- slightly louder than grade I: audible in all positions
- Loud, but not accompanied by a thrill
- Loud, **accompanied by a thrill **
- Loud enough to be heard with a stethoscope barely touching the chest; accompanied by a thrill
- Loud enough to be heard without stethoscope; accompanied by thrill
Which two heart defects may resolve on their own?
- ASD
- VSD
Atrial Septal Defect and Ventricular Septal Defect
What medication can be used to improve cardiac contractibility in heart failure?
aka as congestestive heart failure
Digoxin
What medication can be used to decrease blood pressure in heart failure?
aka as congestestive heart failure
ACEi
(Captopril, Enalapril)
Check BP before administration
What medication can be used to decrease volume overload in heart failure?
aka as congestestive heart failure
Diuretics
(Lasix, Aldactone)
Aldactone is potassium sparing
- What are the two major risks of digoxin
- What must be done before Digoxin administration?
- Bradycardia and Hypokalemia
- Ascultate heart for full min and check potassium levels
arrythmias may also occur; 2nd nurse for dose check
What are two physiological changes with chronic hypoxemia?
Decreased arterial O2 saturation
- polycythemia*
- clubbing
excess production of RBC; causes blood to be viscious
