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