Cardiac disorders Flashcards
What are the most common left to right shunts? (breathless)
Ventricular septal defect
Persistent arterial duct
Atrial septal defect
What are the most common right-to-left shunts (blue)?
Tetralogy of Fallot
Transposition of the great arteries
What are the most common outflow obstruction congenital heart lesions in a well child? (asymptomatic with a murmur)
Pulmonary stenosis
Aortic stenosis
What causes the closure of the foramen ovale?
With the first breath, resistance to pulmonary blood flow falls and the volume of blood through the lungs increases, which leads to a rise in the left atrial pressure. The volume of blood to the right atrium falls because the placenta is excluded. These pressure changes cause closure of the foramen ovale
When does the ductus arteriosus close?
Within the first few hours or days
Where is the ductus arteriosus?
It connects the pulmonary artery to the aorta in fetal life
How does congenital heart disease present?
Antenatal cardiac US Detection of a heart murmur Heart failure Shock Cyanosis
What are the risk factors for congenital heart disease?
Suspected Down syndrome, previous child with heart disease, maternal congenital heart disease
What cardiac abnormalities are linked with down syndrome?
AVSD, VSD
Do all children with murmurs have a congenital heart lesion?
No, must have an ‘innocent murmur’
What are the hallmarks of an innocent ejection murmur?
Asymptomatic patient Soft blowing murmur Systolic murmur only, not diastolic Left sternal edge No radiation No parasternal thrill 4 S's - soft, systolic, aSymtpomatic, left Sternal edge
Why are innocent murmurs often heart during a febrile illness or anaemia?
Because of increased cardiac output
What are the symptoms (not signs) of heart failure?
Breathlessness (particularly on feeding or exertion)
Sweating
Poor feeding
Recurrent chest infections
What are the signs (not symptoms) of heart failure?
Poor weight gain (faltered growth) Tachypnoea Tachycardia Heart murmur, gallop rhythm Enlarged heart Hepatomegaly Cool peripheries
What are the causes of heart failure in neonates?
Obstructed (duct-dependent) systemic circulation: Hypoplastic left heart syndrome Critical aortic valve stenosis Severe coarctation of the aorta Interruption of the aortic arch
What are the causes of heart failure in infants (high pulmonary blood flow)?
Ventricular septal defect
Atrioventricular septal defect
Large persistent ductus arteriosus
What are the causes of heart failure in older children and adolescents?
Right or left heart failure:
Eisenmenger syndrome
Rheumatic heart disease
Cardiomyopathy
What is Eisenmenger syndrome?
Irreversibly raised pulmonary vascular resistance resulting from chronically raised pulmonary arterial pressure and flow.
What may cause peripheral cyanosis?
When a child is cold or unwell from any cause or with polycythaemia
What may cause central cyanosis?
A fall in arterial blood oxygen tension.
What may cyanosis in a newborn infant with respiratory distress be due to?
Cardiac disorders - cyanotic CHD
Respiratory disorders - surfactant deficiency, meconium aspiration, pulmonary hypoplasia
Persistent pulmonary hypertension of the newborn (failure of the pulmonary vascular resistance to fall after birth)
Infection (septicaemia)
What are the important features in an ECG in children?
Arrhythmias
Superior QRS axis (negative deflection in AVF)
Right ventricular hypertrophy (upright T wave in V1)
Left ventricular strain (inverted T wave in V6)
What are the two main types of ASD?
Secundum ASD (80%) (a defect in the centre of the atrial septum involving the foramen ovale) Partial ASD (an inter-atrial communication between the bottom end of the atrial septum and the atrioventricular valves or abnormal valves)
What are the clinical features of ASD?
None (commonly)
Recurrent chest infections/wheeze
Arrhythmias (fourth decade onwards)
What are the physical signs of ASD?
Ejection systolic murmur best heart at the upper left sternal edge
A fixed and widely split second heart sound
What would you find on a CXR of ASD?
Cardiomegaly, enlarged pulmonary arteries and increased pulmonary vascular markings
What would you find on an ECG of secundum ASD?
Partial right bundle branch block, right axis deviation due to right ventricular enlargement
What would you find on an ECG of a partial ASD?
A superior QRS axis (there is a defect in the heart where the AV node is, which becomes displaced and conducts the ventricles superiorly, giving the abnormal axis)
How would you treat an ASD?
Secundum - cardiac catheterisation with insertion of an occlusion device
Partial: surgical correction at about 3-5 years of age
What are the clinical features of a small VSD?
Asymptomatic
Loud pansystolic murmur at lower left sternal edge (loud murmur implies smaller defect)
Quiet pulmonary second sound
What would the investigations show with a small VSD?
CXR: normal
ECG: normal
Echo: anatomical defect
How would you treat a small VSD?
These lesions will close spontaneously, but a paediatrician should monitor the murmur to check this. Good dental hygiene will prevent bacterial endocarditis
What are the clinical features of a large VSD?
Heart failure with breathlessness and failure to thrive
Recurrent chest infection
Tachypnoea, tachycardia and enlarged liver from HF
Soft pansystolic murmur or no murmur
Apical mid-diastolic murmur
Loud pulmonary second sound
What would you see on a CXR of a large VSD?
Cardiomegaly
Enlarged pulmonary arteries
Increased pulmonary vascular markings
Pulmonary oedema
What would you see on a ECG of a large VSD?
Biventricular hypertrophy by 2 months of age
How would you treat a large VSD?
Drug therapy for heart failure with diuretics, often combined with captopril.
Additional calorie input
Pulmonary hypertension -> Eisenmengers syndrome
Surgery to correct at 3-6 months
What are the clinical features of a patent arteriosus ductus?
Continuous murmur beneath the left clavicle.
Increased pulse pressure, with a collapsing or bounding pulse
What would you see on investigations of a patent arteriosus ductus?
CXR and ECG: normal
Echo readily identifies the duct
How would you manage a patent ductus arteriosus?
Closure is with a coil or occlusion device introduced via a cardiac catheter at about 1 year of age.
What is the hyperoxia (nitrogen washout) test used for?
To help determine the presence of heart disease in a cyanosed neonate.
How do you perform a hyperoxia test?
Place the infant in 100% oxygen for 10 mins, if the right atrial arterial PaO2 from a blood gas remains low the child is has ‘cyanotic’ congenital heart disease if lung disease and persistent pulmonary hypertension of the newborn have been excluded
How would you treat a child with a ‘cyanotic’ CHD?
Start prostaglandin infusion. Maintenance of ductal patency is key for these children.
What are the features of tetralogy of fallot?
Large VSD
Overriding of the aorta with respect to the ventricular septum
Subpulmonary stenosis causing right ventricular outflow tract obstruction
Right ventricular hypertrophy
What are the clinical features of TOF?
Diagnosed antenatally Murmur in first 2 months Hypercyanotic spells Clubbing in older children Loud harsh ejection systolic murmur at the left sternal edge from day 1
What are the features of a hypercyanotic spell?
Rapid increase in cyanosis, usually associated with irritability or inconsolable crying because of severe hypoxia, and breathlessness and palor because of tissue acidosis.
What would you see on CXR of TOF?
Relatively small heart, possibly with an uptilted apex due to right ventricular hypertrophy. Pulmonary artery ‘bay’, a concavity on the left heart border where the convex-shaped main pulmonary artery and right ventricular outflow tract would normally be. There may also be decreased pulmonary vascular markings
How would you treat TOF?
Definitive surgery around 6 months of age., before that treat medically
How would you treat a hypercyanotic spell in TOF?
If >15 mins: Sedation and pain relief IV propranolol IV volume administration Bicarbonate to correct acidosis Muscle paralysis and artificial ventilation in order to reduce metabolic oxygen demand
What is transposition of the great arteries?
The aorta is connected to the right ventricle, and the pulmonary artery is connected to the left ventricle.
What are the clinical features of transposition of the great arteries?
Cyanosis on day 2 (when duct closes) is the predominant symptom.
The second heart sound is often loud and single
Usually no murmur, but may be a systolic murmur
What would you find on an CXR of transposition of the great arteries?
Narrow upper mediastinum with an ‘egg on side’ appearance of the cardiac shadow. Increased pulmonary vascular markings are common
How would you treat transposition of the great arteries?
Prostaglandin infusion to maintain patent ductus arteriosus. A balloon atrial septostomy may be required. All patients will require surgery in the first few days of life
What is Eisenmenger syndrome?
If high pulmonary blood flow due to large left-to-right shunt or common mixing is not treated at an early stage, then the pulmonary arteries become thick-walled and the resistance to flow increases. Eventually, at about 10-15 years, the shunt reverses and the teenager becomes blue
How do you treat Eisenmenger syndrome?
Prevention with early intervention for high pulmonary blood flow.
What is a complete AVSD?
A defect in the middle of the heart with a single five-leaflet valve between the atria and ventricles, which stretches across the entire AV junction and tends to leak.
What are the features of a complete AVSD?
Presentation antenatally.
Cyanosis at birth or heart failure at 2-3 weeks.
No murmur
Always a superior axis on the ECG
Management is to treat heart failure medically and surgical repair at 3-6 months.
What are some complex congenital heart diseases?
Tricuspid atresia, mitral atresia, double inlet left ventricle, common arterial trunk
What is tricuspid atresia?
Only the left ventricle is effective, the right being small and non-functional
What lesions cause outflow obstruction in the well child?
Aortic stenosis
Pulmonary stenosis
Adult-type coarctation of the aorta
What is aortic stenosis?
The aortic valve leaflets are partly fused together, giving a restrictive exit from the left ventricle.
What is aortic stenosis often associated with ?
Mitral valve stenosis and coarctation of the aorta.
How does aortic stenosis often present?
With an asymptomatic murmur. In critical cases, a duct-dependent systemic circulation may present with sever heart failure leading to shock
What are the physical signs of aortic stenosis?
Small volume, slow rising pulses Carotid thrill (always) Ejection systolic murmur maximal at the upper right sternal edge radiating to the neck Delayed and soft aortic second sound Apical ejection click
How would you manage aortic stenosis?
Regular clinical and echo assessment to decide when to intervene. Treatment is balloon valvotomy of the aortic valve, which is much safer in older children, most will eventually require a valve replacement.
What is pulmonary stenosis?
The pulmonary valve leaflets are partly fused together, giving a restrictive exit from the right ventricle.
What are the physical signs of pulmonary stenosis?
An ejection systolic murmur best heard at the upper left sternal edge; thrill may be present
An ejection click best heart at the upper left sternal edge
When severe, there is a prominent right ventricular impulse (heave)
How would you manage pulmonary aortic stenosis?
Monitor clinically and with echos. Trans-catheter balloon dilatation is the treatment of choice.
What are the clinical features of coarctation of the aorta?
Present on day 2.
A sick baby, with severe heart failure
Absent femoral pulses
Severe metabolic acidosis
What would you see on CXR of coarctation of the aorta?
Cardiomegaly from heart failure and shock
How would you treat coarctation of the aorta?
Surgical repair is performed soon after diagnosis
What is coarctation of the aorta?
Due to the arterial duct tissue encircling the aorta just at the point of insertion of the duct. When the duct closes, the aorta also constricts, causing severe obstruction to the left ventricular outflow.
What arrhythmias are common in children?
Sinus arrhythmia is normal in children and is detectable as a cyclical change in heart rate with respiration. There is an acceleration during inspiration and slowing on expiration.
What is supraventricular tachycardia?
The heart rate is rapid, between 250 and 300 beats/min.
What are the complications of supraventricular tachycardia?
It can cause poor cardiac output and pulmonary oedema.
How does supraventricular tachycardia present?
Typically, with symptoms of heart failure in the neonate or young infant.
Acutely, how would you treat supraventricular tachycardia?
Circulatory and respiratory support.
Vagal stimulating manoeuvres (carotid sinus massage or cold ice pack to face)
IV adenosine
Electrical cardioversion with a synchronised DC shock if adenosine fails
Long-term, how would you treat supraventricular tachycardia?
Maintenance therapy with flecainide or sotalol. Treatment is stopped at 1 year of age. Those who relapse or are at risk are usually treated with percutaneous radiofrequency ablation or cryoablation of the accessory pathway.
What antibodies is congenital complete heart block associated with?
Anti-Ro or anti-La in the maternal serum, these mothers with have either manifest or latent connective tissue disorders.
How do the antibodies cause congenital complete heart block?
It appears to prevent normal development of the elecal conduction system in the developing heart, with atrophy and fibrosis of the AV node.
What symptoms can long QT syndrome cause?
Sudden LOC during exercise, stress or emotion, usually in late childhood or death.
What is the inheritance pattern of long QT syndrome?
Autosomal dominant
What are the causes of syncope?
Neurocardiogenic (prolonged standing and vagal symptoms)
Situational (defecation, urination, cough or swallowing)
Orthostatic (BP fall >20mmHg after 3 mins)
Ischaemic
Arrhythmic (heart block, SVT, VT)
What are some syncope features that are suggestive of cardiac cause?
Symptoms on exercise (potentially dangerous)
FHx of unexplained death
Palpitations
What is rheumatic fever?
An abnormal immune response to preceding infection with group A beta-haemolytic streptococcus.
What age children does rheumatic fever often affect?
5-15 years
What is the clinical progression of rheumatic fever?
After a latent interval of 2-6 weeks following a pharyngeal infection, polyarthritis, mild fever and malaise develop
What valve is commonly stenosed by rheumatic fever?
Mitral valve stenosis is the most common
What criteria is used to diagnose Rheumatic fever?
Jones Criteria, 2 major or one major and 2 minor criteria following previous group A strep infection
What are the major manifestations of rheumatic fever?
Pancarditis (50%) Polyarthritis (80%) Syndenham chorea (10%) Erythema marginatum (<5%) Subcutaneous nodules (rare)
What are the minor manifestations of rheumatic fever?
Fever Polyarthralgia History of rheumatic fever Raised acute-phase reactants : ESR, CRP, leucocytosis Prolonged PR interval on ECG
How would you treat an acute episode of rheumatic fever?
Bed rest and anti-inflammatories. Aspirin is effective at suppressing the inflammatory response of the joints and heart. It needs to be given in high dosage and serum levels monitored. If not resolved rapidly, give corticosteroids
How should rheumatic fever be treated long term?
Monthly injections penicillin is the most effective prophylaxis, or it can be given orally everyday, recommended to the age of 18-21 years, but more recently advocated for lifelong.
Which children are at risk of infective endocarditis?
All children of any age with congenital heart disease, especially when there is a turbulent jet of blood as with a VSD, coarctation of the aorta and persistent ductus arteriosus or if prosthetic material has been inserted at surgery.
What are the clinical features of infective endocarditis?
Should be suspected with a sustained fever, malaise, raised ESR, unexplained anaemia or haematuria. Other features include splinter haemorrhages in nailed, clubbing, necrotic skin lesions, changing cardiac signs, splenomegaly, neurological signs from cerebral infarction, retinal infarcts, arthritis.
How would you diagnose infective endocarditis?
Blood cultures before antibiotics.
Cross-sectional echo may confirm diagnosis by identification of vegetations but it never excludes it.
Acute-phase reactants are raised.
What organism most commonly causes infective endocarditis?
Strep viridans
How would you treat infective endocarditis?
High dose penicillin in combination with an aminoglycoside, giving 6 weeks of IV therapy. If there is an infected prosthetic valve surgical removal maybe required.
How can you prevent infective endocarditis?
Good dental health
What are the causes of dilated cardiomyopathy?
It may be inherited, secondary to metabolic disease or may result from a direct viral infection of the myocardium
What are the clinical features of dilated cardiomyopathy?
It should be suspected in any child with an enlarged heart and heart failure who has previously been well.
How do you diagnose dilated cardiomyopathy?
Echo
How do you treat dilated cardiomyopathy?
Symptomatically, with diuretics and ACE inhibitors and carvedilol, a beta-adrenoceptor blocking agent.
How do you treat myocarditis?
It usually improves spontaneously, but some children ultimately require heart transplantation
How is pulmonary hypertension associated with the heart?
Most children with pulmonary hypertension have a large post-tricuspid shunt with high pulmonary blood flow and low resistance, e.g. VSD, AVSD or PDA. The pressure falls to normal if the defect is corrected by surgery within 6 months of life.
