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)