Heart conditions Flashcards
(151 cards)
1
Q
What should routine examination of the newborn infant include in terms of assessing heart health?
A
Looking for signs of heart disease or dysmorphic features, assessing pulses and peripheral perfusion in arms and legs, palpating the precordium, listening for heart sounds and murmurs, and looking for signs of respiratory distress, heart failure, and shock.
2
Q
Why is it important to assess pulses and peripheral perfusion in arms and legs during the newborn examination?
A
Why is it important to assess pulses and peripheral perfusion in arms and legs during the newborn examination?
3
Q
What specific aspects of the heart should be assessed during the newborn examination?
A
What specific aspects of the heart should be assessed during the newborn examination?
4
Q
What syndromes are many congenital cardiac abnormalities associated with?
A
Many congenital cardiac abnormalities are associated with specific syndromes.
5
Q
In addition to heart health, what other conditions should be assessed for during the newborn examination?
A
Signs of respiratory distress, heart failure, and shock.
6
Q
Why is it important to look for dysmorphic features during the newborn examination?
A
Many congenital cardiac abnormalities are associated with specific syndromes, which may present with dysmorphic features.
7
Q
What should be done if there is doubt regarding cyanosis or lower limb pulses during the newborn examination?
A
Measure oxygen saturation and blood pressure in all limbs.
8
Q
What is a helpful method of screening newborn infants for hypoxemia in cyanotic heart abnormalities?
A
Pulse oximetry.
9
Q
How can pulse oximetry assist in identifying hypoxemia in newborn infants with cyanotic heart abnormalities?
A
By measuring oxygen saturation levels.
10
Q
How might antenatal ultrasonography contribute to the detection of congenital heart defects?
A
Many congenital heart defects may be detected through antenatal ultrasonography.
11
Q
What should be measured in all limbs if there is doubt regarding cyanosis or lower limb pulses?
A
Oxygen saturation and blood pressure.
12
Q
Why is pulse oximetry particularly useful in screening newborns for hypoxemia?
A
It provides a non-invasive method for measuring oxygen saturation levels.
13
Q
What is the primary cause of heart disease in newborn infants?
A
Congenital structural defects.
14
Q
How often is heart disease in newborn infants attributed to an acquired abnormality in cardiac function and circulation?
A
Rarely
15
Q
What is the typical etiology of heart disease in newborn infants?
A
Congenital structural defects.
16
Q
What type of abnormality in cardiac function and circulation is uncommonly responsible for heart disease in newborns?
A
Acquired abnormalities.
17
Q
What is the relative frequency of congenital versus acquired heart disease in newborn infants?
A
Congenital heart disease is much more common, whereas acquired abnormalities are rare.
18
Q
Heart
disease in the newborn infant usually presents with one or more of the following:
A
- Asymptomatic heart murmur.
- Cyanosis.
- Gradual onset of respiratory distress and heart failure, usually after 2-3weeks.
- Sudden, catastrophic heart failure with shock.
19
Q
What is an innocent or physiological murmur?
A
A short, soft (<3/6), short systolic murmur.
20
Q
When is an innocent or physiological murmur commonly heard in newborns?
A
Soon after birth.
21
Q
What are the typical characteristics of an innocent or physiological murmur?
A
It is short, soft (<3/6), and occurs during systole.
22
Q
What are some common causes of an innocent or physiological murmur in newborns?
A
Flow through a patent ductus arteriosus (PDA), tricuspid regurgitation while pulmonary pressures are falling, and increased flow over a normal pulmonary valve due to a hyperdynamic circulation (e.g., anaemia or fever).
23
Q
Do infants with an innocent or physiological murmur typically exhibit other abnormal cardiac signs?
A
No, they typically have no other abnormal cardiac signs.
24
Q
When does an innocent or physiological murmur usually disappear in newborns?
A
During the first days of life.
25
What conditions may result in a systolic murmur heard well over both sides of the chest and back in an asymptomatic infant?
Peripheral pulmonary stenosis or a small persistent patent ductus arteriosus (PDA).
26
What characteristics are typical of the murmur caused by peripheral pulmonary stenosis or a small persistent PDA?
It is systolic and heard well (<3/6) over both sides of the chest and back.
27
Are these conditions more common in preterm infants?
Yes, both peripheral pulmonary stenosis and small persistent PDAs are common in preterm infants.
28
What may cause a systolic murmur to be heard over both sides of the chest and back in an asymptomatic infant?
Peripheral pulmonary stenosis or a small persistent PDA.
29
What is the typical presentation of an infant with a systolic murmur caused by peripheral pulmonary stenosis or a small persistent PDA?
They are usually asymptomatic.
30
What term describes the intensity of the murmur caused by peripheral pulmonary stenosis or a small persistent PDA?
It is heard well, typically less than 3/6 in intensity.
31
When does the murmur associated with a small ventricular septal defect (VSD) typically become audible in infants?
After day 2, once the pulmonary vascular resistance (PVR) falls significantly and the right heart pressure drops below that of the left heart.
32
What causes the systolic murmur associated with a small VSD?
A left-to-right shunt through the VSD.
33
Where is the systolic murmur associated with a small VSD best heard?
At the lower left sternal border.
34
Do most small VSDs close spontaneously with time?
Yes, most small VSDs do close spontaneously.
35
What complication may arise from larger VSDs in infants around 3 to 6 weeks of age?
Pulmonary overcirculation.
36
At what age may larger VSDs lead to pulmonary overcirculation in infants?
Around 3 to 6 weeks of age.
37
What is a potential presentation of acyanotic Tetralogy of Fallot in a newborn?
A loud, harsh murmur (3/6 or more) in an otherwise well acyanotic newborn.
38
How does adequate pulmonary blood flow affect the appearance of cyanosis in acyanotic Tetralogy of Fallot?
It prevents the appearance of obvious cyanosis.
39
What may occur over time as a result of right ventricular outflow obstruction in acyanotic Tetralogy of Fallot?
The obstruction may worsen as the ventricle and infundibulum hypertrophy.
40
What is a characteristic feature of the murmur associated with acyanotic Tetralogy of Fallot?
It is loud and harsh.
41
In acyanotic Tetralogy of Fallot, why does the right ventricular outflow obstruction potentially worsen over time?
Due to hypertrophy of the ventricle and infundibulum.
42
How does adequate pulmonary blood flow affect the presentation of cyanosis in acyanotic Tetralogy of Fallot?
It prevents obvious cyanosis from appearing.
43
What characteristics of a heart murmur in an infant suggest a serious heart abnormality that requires urgent investigation?
Any loud or long systolic murmur (>3/6), any diastolic murmur, or a murmur associated with signs of respiratory distress, heart failure, cyanosis, shock, or dysmorphic features.
44
What should be done if a <3/6 heart murmur is present in an asymptomatic infant and persists after day 3 of life?
It needs follow-up.
45
What characteristics of a heart murmur in an infant suggest the need for urgent investigation?
Any loud or long systolic murmur (>3/6), any diastolic murmur, or a murmur associated with signs of respiratory distress, heart failure, cyanosis, shock, or dysmorphic features.
46
What should be done if a <3/6 heart murmur persists beyond day 3 of life in an asymptomatic infant?
It requires follow-up.
47
When should a heart murmur in an asymptomatic infant be followed up?
If it persists beyond day 3 of life.
48
What should be done if a heart murmur is found in an infant with no symptoms but has certain characteristics?
It should be urgently investigated if it is loud or long systolic (>3/6), diastolic, or associated with specific signs such as respiratory distress, heart failure, cyanosis, shock, or dysmorphic features.
49
What is peripheral cyanosis commonly attributed to in newborn infants?
Peripheral cyanosis is commonly attributed to cold hands and feet or occurs shortly after birth (within 10 minutes).
50
What does persistent central cyanosis indicate in newborn infants?
Persistent central cyanosis indicates hypoxemia with inadequate arterial oxygen saturation and is usually due to a pulmonary or cardiac condition.
51
What does central cyanosis not responding to 100% oxygen suggest?
It suggests persistent pulmonary hypertension or cyanotic congenital heart disease.
52
What are some severe congenital heart abnormalities that may present with central cyanosis?
Many of these abnormalities start with a 'T'.
53
What are important cardiac causes of cyanosis in newborn infants?
Obstructed pulmonary flow with right-to-left shunting or common mixing of deoxygenated blood from the right heart and oxygenated blood from the left heart.
54
What is the management approach for newborn infants presenting with central cyanosis and important cardiac causes?
Urgent referral and surgery are required for these cases.
55
What clinical presentation may lead to the mistaken diagnosis of congenital cyanotic heart disease?
Central cyanosis associated with persistent pulmonary hypertension
56
What is a characteristic feature of persistent pulmonary hypertension that helps differentiate it from congenital cyanotic heart disease?
There is often a pre- and post-ductal saturation difference of more than 7-10%.
57
In which population is persistent pulmonary hypertension usually seen?
It is usually seen in term infants who have suffered intrapartum hypoxia, often with meconium-stained liquor.
58
What is one potential cause of persistent pulmonary hypertension in newborn infants?
Intrapartum hypoxia.
59
What physiological phenomenon does not occur in infants with persistent pulmonary hypertension after delivery?
There is a significant fall in pulmonary vascular resistance (PVR).
60
What happens when pulmonary pressures exceed systemic pressures in infants with persistent pulmonary hypertension?
There is a right-to-left shunt through the ductus arteriosus and foramen ovale.
61
What component often results in clinical episodes of significant desaturation in infants with persistent pulmonary hypertension?
A dynamic pulmonary vascular over reactivity component.
62
What is the treatment approach for infants with persistent pulmonary hypertension?
Treatment consists of oxygen (the most potent vasodilator), respiratory support, blood pressure support (with inotropes and intravenous fluids), and careful sedation.
63
How can pulmonary resistance be reduced in infants with persistent pulmonary hypertension?
Oral sildenafil (Viagra) or inhaled nitrous oxide can be used to reduce pulmonary resistance.
64
What is the role of oxygen in the treatment of persistent pulmonary hypertension?
Oxygen is the most potent vasodilator and is used in the treatment of persistent pulmonary hypertension.
65
Oxygen is the most potent vasodilator and is used in the treatment of persistent pulmonary hypertension.
Oral sildenafil (Viagra) or inhaled nitrous oxide can also be used to reduce pulmonary resistance
66
Why is careful sedation recommended in the treatment of persistent pulmonary hypertension?
Careful sedation helps manage the dynamic pulmonary vascular over reactivity component and prevents clinical episodes of significant desaturation.
67
What is the likely diagnosis if a newborn infant presents with severe cyanosis, tachypnea, and cardiomegaly in the first few days of life?
Transposition of the great arteries (TGA).
68
What physiological anomaly characterizes transposition of the great arteries?
The aorta leaves the right ventricle, and the pulmonary artery exits the left ventricle, resulting in oxygenated blood being unable to reach the systemic circulation.
69
How does oxygenated blood reach the systemic circulation in infants with transposition of the great arteries?
There may be some mixing at the atrial and ductal level, and pulmonary blood flow increases.
70
What imaging modality may reveal congested lungs in infants with transposition of the great arteries?
Chest X-ray.
71
What is the initial therapeutic intervention for infants with transposition of the great arteries to improve arterial oxygen saturation?
Oral or intravenous prostaglandin therapy to reopen the ductus arteriosus.
72
What surgical procedure is typically required for infants with transposition of the great arteries?
Arterial switch operation, performed early to correct the anomaly.
73
What is the typical presentation of severe Tetralogy of Fallot with severe pulmonary outflow obstruction?
Central cyanosis.
74
What is the characteristic appearance of the heart on a chest X-ray in severe Tetralogy of Fallot?
A boot-shaped heart.
75
How can pulmonary flow be maintained in severe Tetralogy of Fallot with severe pulmonary outflow obstruction?
By keeping the ductus arteriosus open with a prostaglandin E1 infusion (or oral E2).
76
What urgent intervention is typically required for severe Tetralogy of Fallot with severe pulmonary outflow obstruction to establish blood flow to the lungs?
An urgent shunt procedure (subclavian artery to the pulmonary artery) or possible full repair.
77
How might milder forms of Tetralogy of Fallot present clinically?
Milder forms may present as acyanotic with a harsh murmur.
78
What alternative method, besides infusion, can be used to maintain pulmonary flow in severe Tetralogy of Fallot?
Oral prostaglandin E2.
79
Other less common congenital heart abnormalities presenting with cyanosis include
Tricuspid atresia,
Ebstein’s anomaly,
Truncus arteriosus and
Total anomalous
pulmonary venous drainage.
80
What are the potential causes of respiratory distress at birth?
Respiratory distress at birth is usually due to a primary lung condition.
81
When might cyanosis and tachypnea at birth indicate a different underlying condition?
If cyanosis and tachypnea at birth do not respond to oxygen, it may indicate cyanotic heart disease.
82
When does heart failure with respiratory distress typically develop in newborns?
Heart failure with respiratory distress typically develops after a week or more of life, classically around 3-6 weeks for a ventricular septal defect (VSD).
83
What is the usual cause of heart failure with respiratory distress developing after a week or more of life?
It is usually due to pulmonary overcirculation.
84
What physiological changes contribute to the development of heart failure with respiratory distress in newborns?
Once the pulmonary vascular resistance (PVR) and right heart pressure have fallen significantly, the "left-to-right" shunt at the level of the ductus arteriosus, ventricle, or atrium increases and floods the pulmonary vessels
85
Clinical features of neonatal heart failure include:
* Signs of respiratory distress, especially fast breathing.
* Tiring with feeds and failure to thrive, with or without oedema.
* Excessive sweating, especially of the forehead, whilst feeding.
* Tachycardia or gallop rhythm.
* Hepatomegaly
86
What is the most common cause of respiratory distress due to excessive pulmonary flow in preterm infants?
A large persistent ductus arteriosus.
87
What is the function of the ductus arteriosus in utero?
The ductus arteriosus carries blood from the pulmonary artery to the aorta to bypass the nonfunctional lungs.
88
What triggers the closure of the ductus arteriosus after birth?
The higher PaO2 level in response to the lungs replacing the placenta as the respiratory organ triggers muscular spasm, leading to closure of the ductus arteriosus.
89
Why might a ductus arteriosus persist and not close after birth, especially in preterm infants?
The ductus arteriosus may persist and not close after birth, especially in preterm infants, due to immaturity and episodes of hypoxemia preventing natural spasm.
90
What physiological change occurs in the pulmonary artery after delivery that contributes to the shunting of blood from the aorta?
There is a significant fall in pulmonary vascular resistance (PVR) after delivery, leading to a lower mean blood pressure in the pulmonary artery compared to the aorta.
91
What happens to the left-to-right shunt in the lungs over the first 6 weeks of life?
The left-to-right shunt into the lungs increases as the pulmonary vascular resistance (PVR) falls further.
92
How does a large left-to-right shunt affect the lungs?
The flooded lungs become stiff and edematous, leading to respiratory distress.
93
What are some characteristics of pulses in infants with a large left-to-right shunt?
The pulses are bounding or very easily felt, and there is a wide pulse pressure.
94
Where is a systolic murmur typically heard in infants with a large persistent ductus arteriosus?
A systolic murmur is usually heard in the left subclavicular area after day 2-3, as well as over the back.
95
Is it common to hear a diastolic murmur in young infants with a persistent ductus arteriosus?
No, it is unusual to have a diastolic murmur in young infants with a persistent ductus arteriosus.
96
What factor in preterm infants may contribute to the persistence of a patent ductus arteriosus?
An elevated level of prostaglandin.
97
How might underlying inflammatory conditions affect the closure of the ductus arteriosus?
Inflammatory conditions such as septicemia, pneumonia, necrotizing enterocolitis, or bronchopulmonary dysplasia can lead to high prostaglandin levels, which prevent the ductus from closing.
98
What is the recommended approach for managing a patent ductus arteriosus in preterm infants with no significant hemodynamic clinical effects?
A "watchful waiting" approach is advised if the patent ductus arteriosus is not hemodynamically significant.
99
Besides treating the underlying inflammatory condition, what other measures may be needed for managing a patent ductus arteriosus in preterm infants?
General supportive measures may also be necessary.
100
What role do prostaglandins play in the persistence of a patent ductus arteriosus in preterm infants?
Elevated prostaglandin levels can prevent the closure of the ductus arteriosus, especially in preterm infants.
101
What are the signs of increased pulmonary blood flow associated with a hemodynamically significant patent ductus arteriosus (PDA)?
Tachypnea, tachycardia, and poor growth.
102
How can the diagnosis of a hemodynamically significant PDA be confirmed clinically?
Echocardiography can confirm the diagnosis by assessing for a large duct size, large ductal left-to-right shunt, large left atrium, and reversed diastolic flow in the aorta.
103
What findings on echocardiography confirm a hemodynamically significant left-to-right shunt through a PDA?
A large duct size, large ductal left-to-right shunt, large left atrium, and reversed diastolic flow in the aorta.
104
What findings would a chest X-ray typically show in a patient with a hemodynamically significant PDA?
Cardiomegaly and pulmonary plethora.
105
Besides echocardiography, what other diagnostic tool can confirm the presence and severity of a patent ductus arteriosus?
Chest X-ray findings of cardiomegaly and pulmonary plethora can also suggest the presence and severity of a patent ductus arteriosus.
106
hat are the primary management strategies for a hemodynamically significant patent ductus arteriosus (PDA) until it closes spontaneously?
Intravenous fluid restriction, optimizing nutrition, maintaining a normal hemoglobin level, and administering small doses of diuretics.
107
What supportive measure may be needed in the short-term for managing a hemodynamically significant PDA?
Supportive nasal continuous positive airway pressure (CPAP) may be needed.
108
In rare cases where a newborn infant has a confirmed very large ductal shunt and persistent severe respiratory distress, what pharmacological interventions may be considered?
Paracetamol or ibuprofen (Brufen) orally, or indomethacin intravenously, which blocks prostaglandin synthesis
109
What should be done before considering pharmacological intervention for managing a very large ductal shunt and persistent severe respiratory distress in newborn infants?
Infection should be excluded, and all contraindications should be assessed.
110
What is the next step if medical treatment fails in extreme cases of a patent ductus arteriosus?
Surgical ligation of the duct may be considered, particularly in ventilator-dependent cases where medical treatment fails.
111
What physiological consequence occurs in the lungs as the size of a ventricular septal defect (VSD) increases?
As the size of the left-to-right shunt increases due to the VSD, excessive pulmonary blood flow occurs as pulmonary vascular resistance falls.
112
When does respiratory distress and poor feeding typically occur in infants with a moderate to large ventricular septal defect?
Respiratory distress and poor feeding usually occur around 3-6 weeks after birth.
113
What type of murmur may be heard in infants with a moderate to large ventricular septal defect?
A diastolic flow murmur may be heard.
114
What are common complications associated with a large VSD?
Failure to thrive and secondary pneumonia are common complications.
114
Which congenital heart defect is the most common form of congenital heart disease?
Ventricular septal defect (VSD).
115
What cardiac anomaly is frequently associated with trisomy 21 (Down syndrome)?
An endocardial cushion defect, which may include a ventricular septal defect (VSD).
115
What is the recommended management approach for infants with symptomatic VSD?
Infants with symptomatic VSD should be fully investigated and given anti-failure therapy. Large VSDs may require surgical closure.
116
How can a VSD be clinically identified as part of an endocardial cushion defect?
A left axis on ECG may be observed.
117
Why is it recommended for all infants with trisomy 21 to undergo a cardiac evaluation before 3 months of age?
Trisomy 21 infants are at risk of accelerated pulmonary hypertension development, which increases the risks of later surgery.
118
What potential cardiac complication is specifically mentioned as a risk for infants with trisomy 21
Accelerated pulmonary hypertension.
119
How might the presence of a VSD affect the cardiac evaluation of infants with trisomy 21?
It may prompt further assessment for associated cardiac anomalies and monitoring for potential complications like accelerated pulmonary hypertension.
120
What are the potential causes of catastrophic shock and early heart failure in newborn infants?
Underdevelopment of the left side of the heart (hypoplastic left heart syndrome), severe coarctation of the aorta, interrupted aortic arch, or severe aortic stenosis.
121
How does the right ventricle initially maintain systemic circulation in infants with catastrophic shock and early heart failure?
Initially after birth, the right ventricle maintains systemic circulation via the patent ductus arteriosus.
122
When do infants with catastrophic shock and early heart failure typically present?
These infants usually present on day 2 to 14 when the ductus arteriosus closes.
123
What are some clinical manifestations of catastrophic shock and early heart failure in newborn infants?
Poor perfusion, mottled skin, hypotension, poor pulses, and metabolic acidosis
124
How might catastrophic shock and early heart failure be misdiagnosed in newborn infants?
It may be misdiagnosed as sepsis due to similar clinical manifestations such as poor perfusion, mottled skin, hypotension, poor pulses, and metabolic acidosis.
125
What clinical sign suggests the diagnosis of catastrophic shock and early heart failure in newborn infants?
A saturation difference of >3% between the right hand (preductal) and foot (post-ductal).
126
How can prostaglandin E2 administration be beneficial in infants with catastrophic shock and early heart failure?
Prostaglandin E2 orally or a PGE1 infusion can be lifesaving as they keep the ductus arteriosus open, maintaining systemic circulation.
127
What urgent interventions are required for infants with catastrophic shock and early heart failure?
Urgent stabilization and early referral for assessment, with surgery if needed, are required.
128
What is the significance of palpable femoral pulses in newborn infants with catastrophic shock and early heart failure?
Femoral pulses are usually palpable until the ductus arteriosus starts to close, indicating ongoing systemic circulation.
129
What is the prognosis for many infants with catastrophic shock and early heart failure?
Unfortunately, many of these infants die despite treatment efforts.
130
What are some potential causes of heart failure at birth in newborn infants?
Heart failure at birth is rare and can be seen in severely anaemic infants (e.g., Rhesus haemolytic disease, severe blood loss),
infants after severe intrapartum hypoxia,
severe metabolic disturbances (e.g., hypoglycaemia),
arrhythmias (especially paroxysmal atrial tachycardia or complete heart block), and
rarely with myocarditis (e.g., Coxsackie virus).
131
What is a common cause of severe anaemia in newborn infants that can lead to heart failure?
Rhesus haemolytic disease, caused by blood group incompatibility between the mother and baby, can result in severe anaemia in newborn infants, leading to heart failure.
132
What condition can result in severe blood loss in newborn infants and lead to heart failure?
Severe blood loss can occur due to conditions such as birth trauma or complications during delivery, resulting in heart failure in newborn infants.
133
How might severe intrapartum hypoxia contribute to heart failure in newborn infants?
Severe intrapartum hypoxia (lack of oxygen during labor and delivery) can cause damage to the heart muscle, leading to heart failure in newborn infants.
134
What type of arrhythmias can be associated with heart failure at birth?
Paroxysmal atrial tachycardia or complete heart block are arrhythmias that can be associated with heart failure at birth.
135
How is the diagnosis of congenital heart disease often made during pregnancy?
The diagnosis may be made during pregnancy through antenatal ultrasonography.
136
Why might some individuals not receive a prenatal diagnosis of congenital heart disease?
Some individuals may not have access to fetal anomaly scanning or may book too late to have this scan. Additionally, in busy clinics, where cardiac anatomy may not be scrutinized, only a limited anomaly scan, focusing on the four-chamber cardiac view, may be performed.
137
What proportion of congenital heart defects are identified with a limited anomaly scan?
Less than 50% of congenital heart defects are identified with a limited anomaly scan that only includes the four-chamber cardiac view.
138
What might be a reason why some individuals do not have access to fetal anomaly scanning?
Limited access to healthcare services or late initiation of prenatal care could be reasons why some individuals do not have access to fetal anomaly scanning.
139
What are some potential implications of not detecting congenital heart defects prenatally?
Not detecting congenital heart defects prenatally may lead to delayed diagnosis and treatment, potentially resulting in adverse outcomes for the affected infant.
140
What is the most important clue to the diagnosis of congenital heart disease in newborn infants?
The clinical presentation is the most important clue to the diagnosis.
141
Why is detailed examination of the cardiovascular system essential in newborn infants?
Detailed examination of the cardiovascular system is essential for identifying any abnormalities or signs suggestive of congenital heart disease.
142
How can pre-discharge oxygen saturation be used to screen for hypoxemia in newborn infants?
Pre-discharge (>6hrs) oxygen saturation can be measured, with a saturation level of ≥95% considered normal.
143
Besides assessing heart size and shape, what can a chest X-ray reveal in newborn infants with suspected congenital heart disease?
A chest X-ray can also reveal whether the lung fields appear plethoric or oligaemic.
144
What are some diagnostic tests and follow-up procedures recommended for newborns with suspected congenital heart disease if a cardiology service is not immediately available?
Clinical assessment and follow-up at 2 days post-discharge and 7-10 days of life are crucial for critical congenital cardiac defects, and at 4-6 weeks for left-to-right shunt lesions. Detailed echocardiography (ultrasonography) is usually performed at the bedside, and occasionally cardiac catheterization or Magnetic Resonance Angiography (MRA) may be needed.
145
What is the purpose of performing a chest X-ray in the evaluation of congenital heart disease in newborns?
chest X-ray is used to assess heart size and shape and to evaluate whether the lung fields appear plethoric (overinflated) or oligaemic (underinflated).
146
How can an electrocardiogram (ECG) aid in the diagnosis of congenital heart disease in newborns?
An ECG, especially the QRS axis, can provide valuable information. A left axis deviation in combination with acyanotic features may suggest atrioventricular septal defect (AVSD), while a left axis deviation in combination with cyanotic features may suggest tricuspid atresia. Additionally, ECG can detect arrhythmias which may be associated with certain congenital heart defects.
147
What specific aspect of the QRS complex on an ECG is particularly important in the diagnosis of congenital heart disease?
The QRS axis is particularly important, as it can provide clues about the underlying cardiac anatomy and physiology, helping to differentiate between different types of congenital heart defects.
148
How might the appearance of the lung fields on a chest X-ray provide diagnostic information for congenital heart disease?
Plethoric (overinflated) or oligaemic (underinflated) lung fields on a chest X-ray may suggest specific types of congenital heart defects or provide additional information about cardiac function and circulation.
149
Management of an infant with suspected congenital
heart disease
* Oxygen and respiratory support if necessary.
* If a cyanotic heart condition is suspected, give prostaglandin E2 orally or E1
intravenously to keep the ductus open. This should be given immediately in any
infant with suspected cyanotic congenital heart disease as it is often lifesaving.
The standard emergency dose of oral prostaglandin E2 is ¼ tablet crushed in 2 ml
water given via nasogastric tube 1 to 2 hourly.
* Inotropic support with dopamine, dobutamine or adrenaline in hypotensive failure.
* Diuretics (furosemide with or without spironolactone) and reduce fluid intake for
congestive heart failure.
* Correct anaemia and any correctable metabolic problems (Na+, K+, Ca2+, Mg2+, PO4
).
* Optimize nutrition, consider tube feeds if infant is feeding well orally.
* Refer early for cardiologist confirmation and consideration for corrective or
palliative surgery.
* Parents should be counseled about the diagnosis, management and prognosis.
