RNC -NIC PATHOPHYSIOLOGY – CARDIOVASCULAR
DISORDERS QUESTIONS AND ANSWSERS
A large ventricular septal defect (VSD) may not be immediately evident
at birth due to:
A. elevated pulmonary vascular resistance.
B. patency of the ductus venosus.
C. patent ductus arteriosus that prevents flow through the VSD.
D. decreased pulmonary vascular resistance.
A. Large ventral septal defects are not symptomatic at birth because the
pulmonary vascular resistance is normally elevated at this time. As the
pulmonary vascular resistance decreases over the first 6-8 weeks of life,
the amount of shunted blood increases and symptoms may develop.
The ductus venosus converts to a ligament with removal of the placental
circuit at birth. A patent ductus arteriosus is the connection between the
pulmonary artery and the aorta in utero rather than the ventricles.
In an infant with tetralogy of Fallot, the severity of symptoms will be most
affected by which of the following?
A. Degree of pulmonary edema
B. Size of the ventricular septal defect
C. Degree of right ventricular outflow obstruction
D. Size of the patent ductus arteriosus
C. The presence of an obstruction to right ventricular (RV) outflow with a
large ventral septal defect causes a right-to-left shunt at the ventricular
level with arterial desaturation. The greater the obstruction and the lower
the systemic vascular resistance, the greater the right-to-left shunt. Thus
the clinical findings vary with the degrees of RV outflow obstruction.
Patients with mild obstruction are minimally cyanotic or acyanotic. Those
with severe obstruction are most likely to be deeply cyanotic from birth.
Few children are asymptomatic. In those with significant RV outflow
obstruction, many have cyanosis at birth and nearly all have cyanosis by
age 4 months. A patent ductus is the connection between the pulmonary
artery and aorta in utero and does not involve the cardiac septum.
Pulmonary edema is a common occurrence in infants with congestive
heart failure.
,A 500g infant with a patent ductus arteriosus is being treated with
indomethacin. When formulating a plan of care, the nurse should
monitor which of the following parameters?
A. Urinary output
B. Blood pressure and pulses
C. Liver enzymes and bilirubin levels
D. Activity level and state of arousal
A. Indomethacin is an inhibitor of prostaglandin synthesis. Most notably,
it decreases blood flow to the renal system, thus decreasing renal
perfusion and urinary output. If oliguria occurs, electrolytes should be
monitored and renally excreted drugs should be adjusted appropriately.
Gastrointestinal perfusion may also be decreased, but generally not to
the extent of renal function.
An infant presents with cyanosis at birth and is later diagnosed with
transposition of the great vessels per echocardiography. The nurse
recognizes that the degree of cyanosis depends on which of the
following factors?
A. Volume of cardiac output
B. Amount of obstruction to the pulmonary circuit
C. Quantity of pulmonary edema
D. Volume of mixing between pulmonary and systemic circulations
D. In transposition of the great vessels, the degree of cyanosis depends
on the amount of mixing between the pulmonary and systemic
circulations. Oxygenated pulmonary venous blood is returned to the
lungs and desaturated systemic blood is returned to the body. Thus the
two circulations exist in parallel. Some mixing between them must occur
to allow oxygenated blood to reach the systemic circulation and the
desaturated blood to reach the lungs. Pulmonary edema, cardiac output,
and obstruction to the pulmonary circuit do not affect the degree of
cyanosis and/or mixing of the pulmonary and systemic circulations.
A balloon septostomy is done for an infant with transposition of the great
vessels to achieve which of the following?
A. Increase pulmonary and systemic mixing at the atrial level
B. Increase cardiac output by creating a ventricular septal defect
C. Decrease pulmonary and systemic mixing at the ventricular level
D. Create a parallel circulation between the venous and arterial circuits
, A. When an infant has a restrictive atrial septal defect (ASD), a balloon
atrial septostomy, a technique developed by William Rashkind in 1966,
may be performed.
The procedure involves inserting a balloon-tipped catheter across the
foramen ovale into the left atrium. The balloon is then inflated and
forcibly withdrawn so that the catheter tears the septum primum and
enlarges the ASD. Mixing should increase immediately, with a
corresponding increase in arterial oxygen saturation. The ventricular
septal defect is a connection between the right and left ventricles and is
not the site of the balloon septostomy. Parallel circuits do not allow for
the mixing of blood flow.
While performing a pulse oximetry screening on an infant nearing
discharge a nurse notes a differential of 2% between preductal and
postductal readings. The nurse should do which of the following?
A. Notify the neonatologist immediately
B. Consider this a negative screen
C. Retest in 1 hour
D. Instruct the family to schedule a repeat test after discharge
B. A screen result would be considered positive if any oxygen saturation
measures less than 90%, oxygen saturation is less than 95% in both
extremities on three measures - each separated by 1 hour, or there is a
3% absolute difference in oxygen saturation between the right hand and
foot on three measures, each separated by 1 hour. Any screening that is
>95% in either extremity with no more than a 3% absolute difference in
oxygen saturation between the upper and lower extremity would be
considered a "pass" result and screening would end.
The nurse should utilize which of the following parameters to select the
appropriate sized blood pressure cuff?
A. 25% greater than the width of the extremity
B. 50% greater than the width of the extremity
C. The same width as the extremity
D. 75% greater than the width of the extremity
A. The cuff width should be 25% greater than the width of the
extremity. The blood pressure reading will be falsely elevated if the cuff
is too narrow and falsely low if the cuff is too large.
An infant with a ventricular septal defect presents with a loud,
pansystolic murmur at birth but is otherwise asymptomatic. The nurse
would anticipate the subsequent development of symptoms at 1-2
DISORDERS QUESTIONS AND ANSWSERS
A large ventricular septal defect (VSD) may not be immediately evident
at birth due to:
A. elevated pulmonary vascular resistance.
B. patency of the ductus venosus.
C. patent ductus arteriosus that prevents flow through the VSD.
D. decreased pulmonary vascular resistance.
A. Large ventral septal defects are not symptomatic at birth because the
pulmonary vascular resistance is normally elevated at this time. As the
pulmonary vascular resistance decreases over the first 6-8 weeks of life,
the amount of shunted blood increases and symptoms may develop.
The ductus venosus converts to a ligament with removal of the placental
circuit at birth. A patent ductus arteriosus is the connection between the
pulmonary artery and the aorta in utero rather than the ventricles.
In an infant with tetralogy of Fallot, the severity of symptoms will be most
affected by which of the following?
A. Degree of pulmonary edema
B. Size of the ventricular septal defect
C. Degree of right ventricular outflow obstruction
D. Size of the patent ductus arteriosus
C. The presence of an obstruction to right ventricular (RV) outflow with a
large ventral septal defect causes a right-to-left shunt at the ventricular
level with arterial desaturation. The greater the obstruction and the lower
the systemic vascular resistance, the greater the right-to-left shunt. Thus
the clinical findings vary with the degrees of RV outflow obstruction.
Patients with mild obstruction are minimally cyanotic or acyanotic. Those
with severe obstruction are most likely to be deeply cyanotic from birth.
Few children are asymptomatic. In those with significant RV outflow
obstruction, many have cyanosis at birth and nearly all have cyanosis by
age 4 months. A patent ductus is the connection between the pulmonary
artery and aorta in utero and does not involve the cardiac septum.
Pulmonary edema is a common occurrence in infants with congestive
heart failure.
,A 500g infant with a patent ductus arteriosus is being treated with
indomethacin. When formulating a plan of care, the nurse should
monitor which of the following parameters?
A. Urinary output
B. Blood pressure and pulses
C. Liver enzymes and bilirubin levels
D. Activity level and state of arousal
A. Indomethacin is an inhibitor of prostaglandin synthesis. Most notably,
it decreases blood flow to the renal system, thus decreasing renal
perfusion and urinary output. If oliguria occurs, electrolytes should be
monitored and renally excreted drugs should be adjusted appropriately.
Gastrointestinal perfusion may also be decreased, but generally not to
the extent of renal function.
An infant presents with cyanosis at birth and is later diagnosed with
transposition of the great vessels per echocardiography. The nurse
recognizes that the degree of cyanosis depends on which of the
following factors?
A. Volume of cardiac output
B. Amount of obstruction to the pulmonary circuit
C. Quantity of pulmonary edema
D. Volume of mixing between pulmonary and systemic circulations
D. In transposition of the great vessels, the degree of cyanosis depends
on the amount of mixing between the pulmonary and systemic
circulations. Oxygenated pulmonary venous blood is returned to the
lungs and desaturated systemic blood is returned to the body. Thus the
two circulations exist in parallel. Some mixing between them must occur
to allow oxygenated blood to reach the systemic circulation and the
desaturated blood to reach the lungs. Pulmonary edema, cardiac output,
and obstruction to the pulmonary circuit do not affect the degree of
cyanosis and/or mixing of the pulmonary and systemic circulations.
A balloon septostomy is done for an infant with transposition of the great
vessels to achieve which of the following?
A. Increase pulmonary and systemic mixing at the atrial level
B. Increase cardiac output by creating a ventricular septal defect
C. Decrease pulmonary and systemic mixing at the ventricular level
D. Create a parallel circulation between the venous and arterial circuits
, A. When an infant has a restrictive atrial septal defect (ASD), a balloon
atrial septostomy, a technique developed by William Rashkind in 1966,
may be performed.
The procedure involves inserting a balloon-tipped catheter across the
foramen ovale into the left atrium. The balloon is then inflated and
forcibly withdrawn so that the catheter tears the septum primum and
enlarges the ASD. Mixing should increase immediately, with a
corresponding increase in arterial oxygen saturation. The ventricular
septal defect is a connection between the right and left ventricles and is
not the site of the balloon septostomy. Parallel circuits do not allow for
the mixing of blood flow.
While performing a pulse oximetry screening on an infant nearing
discharge a nurse notes a differential of 2% between preductal and
postductal readings. The nurse should do which of the following?
A. Notify the neonatologist immediately
B. Consider this a negative screen
C. Retest in 1 hour
D. Instruct the family to schedule a repeat test after discharge
B. A screen result would be considered positive if any oxygen saturation
measures less than 90%, oxygen saturation is less than 95% in both
extremities on three measures - each separated by 1 hour, or there is a
3% absolute difference in oxygen saturation between the right hand and
foot on three measures, each separated by 1 hour. Any screening that is
>95% in either extremity with no more than a 3% absolute difference in
oxygen saturation between the upper and lower extremity would be
considered a "pass" result and screening would end.
The nurse should utilize which of the following parameters to select the
appropriate sized blood pressure cuff?
A. 25% greater than the width of the extremity
B. 50% greater than the width of the extremity
C. The same width as the extremity
D. 75% greater than the width of the extremity
A. The cuff width should be 25% greater than the width of the
extremity. The blood pressure reading will be falsely elevated if the cuff
is too narrow and falsely low if the cuff is too large.
An infant with a ventricular septal defect presents with a loud,
pansystolic murmur at birth but is otherwise asymptomatic. The nurse
would anticipate the subsequent development of symptoms at 1-2
