Deck 24: Congenital Cardiac Defects

Question 1

Which of the following methods is involved in the management of a PDA?

A)Increasing the circulating volume
B)Maintaining/optimizing the hematocrit at the low end of normal hemoglobin level
C)Administering indomethacin
D)Administering digoxin

Answer 1

C
Medical management includes maintaining euvolemia and by optimizing the hemoglobin to ensure adequate oxygen delivery.In mechanically ventilated patients,increasing PEEP may serve to decrease the pulmonary blood flow by increasing PVR.In addition nonsteroidal anti-inflammatory agents such as indomethacin and ibuprofen are often used in the medical management of PDA.Indomethacin may be used prophylactically to prevent PDA and therapeutically to treat a symptomatic PDA.A dose of indomethacin (0.2 mg/kg/dose IV)given in the first 24 hours of life can be effective in preventing a PDA.Therapy later in life is usually given over a 48-hour period.Doses of 0.1 to 0.2 mg/kg/dose IV every 12 to 24 hours are effective.Side effects are uncommon but include oliguria,renal insufficiency,and dilutional hyponatremia.Ibuprofen may also be used,though a recent meta-analysis found that the use of ibuprofen was associated with increased incidence of chronic lung disease when compared to indomethacin.

Question 2

Which of the following statements describe truncus arteriosus?
I)The pulmonary artery arises from the left ventricle,and the aorta stems from the right ventricle.
II)If PVR increases relative to systemic vascular resistance (SVR),more blood flows to the lungs through the truncus,decreasing systemic cardiac output.
III)If SVR decreases relative to PVR,blood flow will be shunted from right to left,bypassing the lungs.
IV)A large VSD allows total mixing of blood from the two ventricles.

A)I and III only
B)II and IV only
C)I,II,and IV only
D)I,III,and IV only

Answer 2

D
Truncus arteriosus refers to a rare defect where a single great artery arises from the ventricles of the heart,supplying the systemic,pulmonary,and coronary arteries (see Figure 24-18 in the textbook).A large VSD allows complete mixing of blood in the ventricles.The blood passes through a truncal valve before passing into the common truncus.The cardiac output and systemic oxygen saturations are determined by the balance between PVR and SVR.As PVR drops in the first several days of life,more blood flows to the lungs relative to the body,resulting in decreased systemic perfusion.If SVR decreases,blood will flow more to the body,leading to decreased pulmonary blood flow and hypoxemia.

Question 3

Which of the following physiologic mechanisms need to be in place to ensure adequate systemic perfusion in infants with HLHS?

A)Presence of an ASD
B)Presence of a mitral regurgitation
C)Adequate left atrial function
D)Presence of a PDA

Answer 3

D
Adequate systemic perfusion in these infants depends on the presence of a nonrestrictive atrial septal connection,adequate right ventricular function,a patent ductus arteriosus,and a balance between the pulmonary and systemic circulations.

Question 4

Which of the following medications is the most common preoperative treatment to minimize preductal constriction until surgical correction of coarctation of the aorta can be achieved?

A)Indomethacin
B)Prostaglandin E₁
C)Negative inotropes
D)Diuretics

Question 5

Which of the following vessels return blood to the right ventricle?
I)Pulmonary vein
II)Inferior vena cava
III)Superior vena cava
IV)Coronary sinus

A)I and IV only
B)II and III only
C)I,II,and III only
D)II,III,and IV only

Question 6

Which of the following blood flow patterns occurs in complete transposition of the great arteries?

A)The systemic venous blood passes through the right heart chambers.
B)The pulmonary venous blood traverses the left side of the heart and then returns to the systemic circulation.
C)When PVR increases relative to SVR,blood flow increases through the ductus arteriosus.
D)Systemic venous blood flows to the lungs after leaving the right ventricle.

Question 7

Identify the congenital cardiac defect depicted in the following illustration:

A)Atrial septal defect
B)Hypoplastic left ventricular syndrome
C)Hypoplastic right ventricular syndrome
D)Atrioventricular canal defect

Question 8

Which of the following clinical pathophysiologic manifestations are consistent with a large ventricular septal defect (VSD)?
I)The majority of the blood flow is shunted from left right to right left.
II)Shunting typically occurs during ventricular diastole,which causes left atrial enlargement.
III)Chest radiography reveals an enlarged cardiac silhouette and increased pulmonary vascular markings,increasing pulmonary blood flow.
IV)Thickening and fibrosing of the pulmonary veins develop,decreasing pulmonary artery pressure.

A)II and III only
B)I and IV only
C)I,II,and III only
D)II,III,and IV only

Question 9

How should the therapist interpret a preductal-to-postductal PaO₂ difference of 8 mm Hg in a neonate?

A)Unreliable data
B)Absence of ductal shunting
C)Presence of ductal shunting
D)Inconclusive data

Question 10

The therapist is treating a child with TOF who appears to be having a "tet" spell.What should the therapist suggest to treat this event?
I)Beta blockers
II)Knee-chest position to increase SVR
III)Morphine sulfate
IV)Oxygen

A)IV only
B)I and III only
C)I and IV only
D)I,II,III,and IV

Question 11

Which of the following clinical manifestations is consistent with an atrial septal defect (ASD)?

A)An ASD often causes congestive heart failure (because of decreased pulmonary blood flow).
B)The right ventricle may become hypertrophic (right ventricular hypertrophy).
C)Most patients with an ASD are symptomatic in the neonatal intensive care unit,presenting with right atrial enlargement.
D)Chest radiographs are usually abnormal.

Question 12

Which of the following congenital cardiac anomalies is classified as conotruncal,associated with a "boot-shaped" appearance of the heart?

A)Tetralogy of Fallot
B)Transposition of the great vessels
C)Coarctation of the aorta
D)Atrioventricular canal defect

Question 13

Why must supplemental oxygen be judiciously administered to patients with an atrioventricular canal defect?

A)To prevent the development of retinopathy of prematurity
B)To avoid oxygen-induced hypoventilation
C)To minimize pulmonary vascular dilation
D)To reduce oxidative stress

Question 14

What should the therapist select as target gas exchange parameters after surgical intervention for infants with hypoplastic left ventricular syndrome HLHS?

A)pH < 7.35
B)PaO₂ of 60 mm Hg and PaCO₂ of 60 mm Hg
C)pH > 7.45
D)PaO₂ of 40 mm Hg and PaCO₂ of 40 mm Hg

Question 15

What factor is responsible for closure of the foramen ovale?

A)Increased PaO₂
B)Increased pressure on the left side of the heart
C)Blood flowing through the lungs
D)High pulmonary vascular resistance

Question 16

Identify the following congenital cardiac anomaly:

A)Truncus arteriosus
B)Hypoplastic left ventricle
C)Transposition of the great vessels
D)Ventricular septal defect

Question 17

Which of the following strategies can be used to increase PVR in infants with HLHS?

A)Fio₂ < 0.21
B)Induce hypocapnia
C)Administer indomethacin
D)Close the PDA

Question 18

For which of the following congenital cardiac defects may spontaneous closure of the ductus arteriosus be catastrophic?
I)Tetralogy of Fallot with pulmonary atresia
II)Atrial septal defect
III)Severe coarctation of the aorta
IV)Hypoplastic left heart syndrome

A)I and III only
B)III and IV only
C)I,II,and IV only
D)I,III,and IV only

Question 19

Which of the following clinical features characterize a critical aortic stenosis in a neonate?

A)Chest radiography reveals pleural effusion and pulmonary engorgement.
B)The neonate often has metabolic alkalosis.
C)The neonate presents in cardiogenic shock with hypotension.
D)These infants are rarely symptomatic during the first month of life.

Question 20

At birth,what factor causes dilation of the pulmonary vascular bed and a decrease in the pulmonary vascular resistance?

A)Increased arterial partial pressure of oxygen (PaO₂)
B)Decreased arterial partial pressure of carbon dioxide (PaCO₂ )
C)Lung inflation
D)Circulating indomethacin

Question 21

The therapist is setting pulse oximetry to determine the presence of right-to-left shunt in an infant suspected of having a heart defect.Where should the therapist place the pulse ox probe to obtain the most accurate measure of preductal oxygen saturation?

A)Any finger of the right hand
B)Any finger of the left hand
C)Left earlobe
D)Lower extremities

Question 22

The therapist is treating a child with a congenital heart defect who is unresponsive to oxygen therapy.Although the chest X-ray is relatively normal,the heart is described as "egg-shaped." Which of the following heart defects is more consistent with this description?

A)Complete transposition of the great arteries
B)Coarctation of the aorta
C)Truncus arteriosus
D)Tetralogy of Fallot

Question 23

When using subambient oxygen therapy,what range of oxygen saturations should the therapist target?

A)>95% to 95%
B)85% to 90%
C)75% to 85%
D)70% to 80%

Question 24

A therapist monitoring an infant after a Blalock-Tausig shunt placement notices a significant drop in the end-tidal carbon dioxide (ETCO₂)despite no changes in the infant's respiratory rate.How should the therapist interpret this change?

A)The infant has dramatically improved ventilation by breathing deeply.
B)The ETCO₂ monitor is not accurate.
C)Loss of pulmonary blood flow through the shunt
D)Tricuspid regurgitation