C - congential heart defects

Question 1

Cyanotic vs acyanotic heart defects?

Answer 1

Based on presence or absence of cyanosis

Question 2

Risk factors of CYANOTIC heart defects? (4)

Answer 2

1. Chromosomal abnormalities of foetus
2. Maternal infections
3. Chronic illnesses
4. Teratogens:
   ○ Isotretinoin
   ○ Alcohol
   ○ Cocaine
   ○ Tobacco smoke
   ○ Heavy metals (eg. mercury)

Question 3

What are the 4 heart abnormalities of the tetralogy of fallot? What is the consequence of ToF?

Answer 3

1. Pulmonary stenosis
   a. Narrowing of pulmonary valve
2. Right ventricular hypertrophy
   a. Enlargement of right ventricle
3. Ventricular septal defect
   a. Gap in the ventricular septum that separates the right and left ventricles
4. Overriding aorta
   a. Aorta is shifted and sits above VSD

Result
- Oxygen rich blood and oxygen poor blood in the right and left ventricle mix due to VSD → then pumped out of overriding aorta

Question 4

What is and what happens when one has Tricuspid atresia ? (1)

Answer 4

• tricuspid valve that normally prevents blood from returning to R atrium when R ventricle contracts is malformed / fails to develop entirely

Result
- oxygen poor blood returning to RA cannot enter into RV
- Atrial septal defect (ASD) is needed to mix blood in R and L atrium
- Ventricular septal defect (VSD) is needed to mix blood in R and L ventricle

Question 5

What is and what happens during the transposition of great arteries? (1)

Answer 5

Aorta and pulmonary trunk swap locations

Result
- Oxygen poor blood returning to R side of heart is pumped into aorta and rest of body instead of the pulmonary artery and lungs

Question 6

Define and state the result of having Tricuspid ateriosus ?

Answer 6

Truncus arteriosus does not split properly into aorta and pulmonary artery during foetal development

• Extra large vessel sits above both ventricles and allows deoxygenated + oxygenated blood to mix before getting pumped to the lungs and rest of body

Question 7

total anomalous pulmonary venous return (TAPVR)

Answer 7

All 4 pulmonary veins form abnormal connections
- Instead of returning blood from lungs to RA → conntect to LA / SVC / IVC
- Result = oxygen rich blood from lungs return to R side of heart (pumped back to lungs)

Condition is only compatible with life if there is ASD that allows some of the blood in RA to flow into LA where it could eventually be pumped into systemic circulation

Question 9

Complications?

Answer 9

Persistence of deoxygenated blood in systemic circulation → chronic hypoxia → body responds by producing more RBCs (polycythemia)

Heart can also fail to pump more oxygenated blood to tissues → heart failure

O2 supply gets too low → result in CVA

● Arrhythmias
● Embolism
● Infective endocarditis
● Brain abscess formation
● Pulmonary vascular disease
● Death

Question 10

Clinical Manifestations? (6)

Answer 10

● Cyanosis (present at birth / within first few weeks of life)
● Lethargy
● Tachypnea
● Activity intolerance
● Clubbing of fingers and toes
● Feeding problems → poor weight gain / FTT

Question 11

What is a clinical manifestation specific to ToF?

Answer 11

Can have acute and severe cyanotic episodes / “Tet spells”

• feeding, exercise, or crying, cause spasm of the infundibular septum & worsens the stenosis and increases the obstruction to pulmonary blood flow
  = right ventricular outflow tract obstruction ⇒ results in increased right to left shunting, eventually decreasing the blood flow through the lungs, causing a fall in arterial oxygen saturation
• Lack of oxygen causes tachypnea or rapid abnormal breathing; and increases the activity of the sympathetic nervous system -> increasing heart contractility and even more obstruction of the right ventricular outflow tract -> cyanosis occurs

Question 12

What do Tet spell patients do?

Answer 12

• Seen squatting / assuming foetal position
• position increases the peripheral vascular resistance by kinking the femoral artery, which improves the pulmonary blood flow and relieves the client
• During auscultation → large defects can be heard as murmurs (from blood moving through defect)

Question 13

Diagnosis of cyanotic heart defect? (8)

Answer 13

● Mother’s Hx during pregnancy and physical assessment of client
● Echocardiography → visualise defect
● Prenatal detection → standard obstetric US exam
● Angiography, pulse oximetry
● CXR, CT, MRI → identify structural abnormalities
● ToF → classic sign found on XR is an enlarged, boot-shaped heart
● ECG → should be done to look for arrhythmias
● Cardiac catheterization → sometimes performed to assess extent of defect

Question 14

Treatment?

Answer 14

● Dependent on type of defect
● Begins with oxygen supplementation
● HF clients
○ Medications — digoxin, diuretics
● Prevention of infective carditis
○ Prophylactic antibiotics
● Prostaglandin E1 infusion → keep ductus arteriosus open
○ Allow blood from pulmonary artery and aorta to mix
○ Increases oxygen level of blood going to rest of the body
● Surgery
○ Correction of defect (in early infancy / during first year of life)
○ Palliative shunt — surgical procedure in which the aorta is connected to the pulmonary trunk, in order to increase the pulmonary blood flow.
○ Severe cases — heart transplantation

Question 15

Nursing Care?

Answer 15

● Priority goal: assist in maintaining oxygen
● Asses infant’s oxygenation: initiate pulse oximetry, assess vital signs, respiratory effort, skin colour

● Report to physician
○ Signs of respi distress: tachypnea, nasal flaring, retractions, grunting, decreased oxygen saturation, and cyanosis

Provide supplementary oxygen
- dilate the pulmonary vasculature; establish IV access and infuse the ordered fluids to increase right ventricular filling and pulmonary blood flow; and prostaglandin E1 to maintain ductal patency and promote pulmonary blood flow
- Decrease risk of hypercyanotic episodes (tet spells)
- Maintain calm, therapeutic environment to prevent agitation
- If tet spell occurs → place the infant into a knee-chest position, which will increase systemic vascular resistance and promote systemic venous return to the right side of the heart and into the pulmonary circulation
- Continue to monitor them closely, and immediately report if the tet spell persists
- Administer medications (morphine — for sedation; β-blockers — to relax outflow tract of RV and promote pulmonary blood flow)

If these interventions don’t resolve the cyanosis, administer the prescribed phenylephrine which will improve outflow from the right ventricle to the lungs
- When the infant is stable, assist with preparing them for complete repair of the heart defect.

Question 16

main types of ACYANOTIC heart defects? (4)

Answer 16

○ ventricular septal defect (VSD) — most common
○ atrial septal defect (ASD)
○ patent ductus arteriosus (PDA)
○ coarctation of the aorta

Question 17

Common risk factors of ACYANOTIC heart defects? (4)

Answer 17

● Maternal infections
● Chronic illnesses
● Exposure to teratogens
○ Isotretinoin
○ Alcohol
○ Cocaine
○ Tobacco smoke
○ Heavy metals (eg. mercury)

● Specific risk factors for patent ductus arteriosus
○ Premature birth
○ Asphyxia during delivery
○ Rubella infection during pregnancy

Question 18

Pathology of acyanotic congenital heart defects?

Answer 18

idk if need

Question 19

Complications? (3)

Answer 19

● Arrhythmias
● Embolism
● Infective endocarditis

Question 20

Clinical Manifestations of ACYANOTIC heart defects?

Answer 20

● Typically asymptomatic

OR
clients can develop:
○ Tachypnea
○ Tachycardia
○ Activity intolerance

can experience
○ Feeding problems ⇒ lead to FTT or poor weight gain

● On auscultation → defects can cause murmurs (different for each defect)
○ VSD → pansystolic murmur (louder and harsher in small defects, softer in larger ones)
○ ASD → soft, midsystolic murmur (often described as a swishing sound)
○ PDA → continuous systolic murmur that extends into diastole
○ Coarctation of aorta → could also cause systolic murmur

■ characteristic finding is a difference between upper and lower limb blood pressure, with blood pressure in the upper limbs being higher; and pulses in the lower extremities will be decreased or absent

Question 21

Diagnosis of ACYANOTIC heart defects?

Answer 21

● Mother’s Hx during pregnancy and physical assessment
● Echocardiography to visualise defect
● Prenatal detection → standard obstetric US exam
● CXR, CT, MRI
● ECG → look for arrhythmias
● Cardiac catheterization → performed to assess extent of defect

Question 22

Treatment of ACYANOTIC heart defects?

Answer 22

● Dependent on type of defect
● Most close on their own during first year of life → do not require treatment

If heart failure:
○ Digoxin
○ Diuretics
○ Potassium supplements

● Prevention of infective endocarditis
○ Prophylactic antibiotics

● Patent ductus arteriosus
○ Indomethacin → close PDA

● Coarctation of aorta
○ Prostaglandin E1 infusion → can keep the ductus arteriosus open but also seems to relax the tissue of the coarctation segment ⇒ helps increase blood flow to the body past the area of coarctation

● Surgery
○ Surgical correction of defect
○ Heart transplantation

Question 23

Priority nursing goals of ACYANOTIC heart defects?

Answer 23

● assist in maintaining adequate cardiac output and provide nutritional support.
● Assess the infant’s cardiopulmonary status
○ checking their vital signs
○ auscultating their heart and lung sounds
○ palpating their peripheral pulses
○ Immediately report signs of decreased cardiac output and pulmonary congestion
■ including tachycardia, decreased peripheral pulses, tachypnea, pulmonary crackles, intercostal retractions, or nasal flaring
● Administer the prescribed medications (eg. digoxin) to support adequate cardiac function and diuretics to reduce pulmonary edema.
● Assess the infant’s growth and development, by plotting their weight, length, and head circumference on a growth chart.
● Ask the caregivers about their infant’s feedings to determine how often and how much their baby eats.
○ Infants with VSD often tire easily with feedings
○ But infants with VSD will also have increased nutritional needs due to their increased cardiovascular demands.
○ ⇒ Encourage continued breastfeeding + need to supplement the infant’s diet by administering the prescribed high-calorie formula, by orogastric or nasogastric tube.