cardiology Flashcards
What is a ventricular septal defect
A congenital hole anywhere in the ventricular septum causing a left to right shunt
Explain how VSDs can cause pulmonary HTN and HF
- A left to right shunt leads to right sided overload, right HF and increased flow into the pulmonary vessels
- extra blood flowing through the right ventricle increases the pressure in the pulmonary vessels over time, causing pulmonary HTN
Give one genetic condition commonly associated with VSDs
Down’s syndrome
VSDs can be considered small or large. Which is more common
Small VSDs (80-90%)
What is the key distinguishing factor between small and large VSDs in terms of size
Small VSDs are smaller than the aortic valve (<3mm) whereas large VSDs are the same size or bigger than the aortic valve
2 clinical features of a small VSD
- Typically asymptomatic
- Loud pansystolic murmur at the left lower sternal border
Give 3 clinical features of a large VSD
- Dyspnoea/ tachypnoea
- Failure to thrive
- Soft pansystolic murmur/ no murmur
In VSDs, where can the murmur be heard best
Left lower sternal border in the third and fourth intercostal spaces
How are VSDs investigated
- GS: ECHO - show precise anatomy of defect
- CXR - may show cardiomegaly and enlarged pulmonary arteries if large defect
How are small VSDs managed
- Should be monitored as they often close spontaneously
- Maintain good dental hygiene to prevent bacterial endocarditis
3 complications of VSDs
- Einsenmenger syndrome
- Endocarditis
- Heart failure
How are large VSDs managed
- reduce risk of IE: Abx prophylaxis
- surgical correction: open heart or transvenous catheter closure
- HF: Diuretics +/- captopril
What is Eisenmenger’s syndrome
the reversal of a left-to-right shunt in a congenital heart defect due to pulmonary hypertension
What causes Eisenmenger’s syndrome
occurs when an uncorrected left-to-right shunt leads to remodelling of the pulmonary microvasculature, eventually causing obstruction to pulmonary blood and pulmonary hypertension.
Features of Eisenmenger’s syndrome
- original murmur may disappear
- cyanosis
- clubbing
- right ventricular failure
- haemoptysis, embolism
What is an atrial septal defect
Congential hole in the septum between the atria that causes a left to right shunt
Give 3 RFs of atrial septal defects
- maternal smoking in 1st trimester
- maternal diabetes
- maternal rubella
Give 2 types of atrial septal defects
- Secundum ASD- mc
- Partial atrioventricular septal defect (primum ASD)
Give symptoms of atrial septal defects in both child and adult
- Child: typically asymptomatic, recurrent chest infections
- Adult: present with dyspnoea and arrhythmias
Give 2 cardiac signs of atrial septal defects
- Ejection systolic murmur, louder on inspiration, heard at the upper sternal border
- Fixed and widely split second heart sound
How are atrial septal defects investigated
- ECHO - diagnostic
ECG: - secundum: partial RBBB, R axis deviation
- partial AVSD: RBBB, left axis deviation, prolonged PR
- CXR - cardiomegaly
How are atrial septal defects managed
- <1mm - manage conservatively, spontaneous closure
- Secundum ASD - transvenous catheter closure
- primum - surgical correction
Give 4 complications of atrial septal defects
- stroke due to VTE
- Atrial fibrillation or atrial flutter
- Pulmonary HTN and right HF
- Eisenmenger syndrome
Explain why atrial septal defects can cause a stroke in patients with a DVT
- Clot from DVT can travel from the right atrium to the left across the ASD
- Clot can travel to the aorta and up to the brain causing a large stroke
What is patent ductus arteriosus
- Persistent connection between the aorta and pulmonary artery causing a left to right shunt
- Failure of the ductus arteriosus to close one month after exp delivery date
How is a patent ductus arteriosus diagnosed
ECHO
* size and characteristics of shunt
* LVH/ RVH
Give 5 clinical features of a patent ductus arteriosus
- left subclavicular thrill
- continuous machinery murmur at upper left sternal edge
- large volume, bounding, collapsing pulse
- heaving apex beat
- wide pulse pressure
How is a patent ductus arteriosus managed
- asymptomatic: observe for spontaneous closure
- Indomethacin or Ibuprofen inhibits prostaglandin and stimulates duct closure
- Closure via cardiac catheterisation around 1 year old (sooner if more severe)
Give 2 RFs of a patent ductus arteriosus
- Maternal rubella
- Prematurity
What are the 4 cardinal anatomical features of Tetralogy of Fallot
- Ventricular septal defect
- Overriding aorta
- Pulmonary valve stenosis
- Right ventricular hypertrophy
What kind of shunt is caused by Tetralogy of Fallot
Right to left
Give 3 RFs for Tetralogy of Fallot
- Rubella
- Maternal age (>40)
- Alcohol consumption during pregnancy
5 clinical features of Tetralogy of Fallot
- Cyanosis
- HF before age 1 in severe cases
- Harsh ejection systolic murmur due to pulmonary stenosis
- Clubbing in older kids
- Hypercyanotic (tet) spells that may result in loss of consciousness
Describe tet spells
- rapid increase in cyanosis due to near occlusion of the right ventricular outflow tract
- features: tachpnoea, severe cyanosis, may result in LOC
- Kids may squat or put their knees to their chest
- typically occurs when infant is upset, in pain or has a fever
What determines the degree of cyanosis and clinical severity in tetralogy of fallot
The severity of the right ventricular outflow tract obstruction due to pulmonary stenosis
Investigations for Tetralogy of Fallot
- GS: ECHO - demonstrate cardinal features
- CXR - boot shaped heart
- ECG - RVH
How is Tetralogy of Fallot managed
- Definitive surgical repair around 6 months - open heart
- Neonates with profound cyanosis: prostaglandin (alprostadil) infusion to maintain patent ductus arteriosus
When and how are tet spells managed
- when lasting over 15 mins
- manoeuvres to increase systemic venous return
- Sedation and IV morphine - calm the child
- IV propanolol
- IV fluids
- Na bicarbonate - reverse acidosis
- Supplementary O2
What is transposition of the great arteries
When the aorta is connected to the right ventricle and the pulmonary artery is connected to the left ventricle
Why is transposition of the great arteries life threatening after birth
- There is no connection between the systemic and pulmonary circulation
- The baby will be cyanosed
Survival of a baby with transposition of the great arteries depends on what?
Presence of a naturally occurring associated anomaly
* i.e. left to right shunt - AVD, VSD, PDA which will allow blood to mix
Clinical features of transposition of the great arteries
- Cyanosis
- loud single S2
- prominent right ventricular impulse is palpable on exam
- tachycardia, tachypnoea
- Delayed presentation if there is an associated anomaly that allows mixing
Investigations for transposition of the great arteries
- ECHO
- CXR - narrow mediastinum and cardiomegaly (egg on string)
How is transposition of the great arteries managed
- Prostaglandin infusion - Maintain patency of ductus arteriosus to improve mixing
- Balloon atrial septostomy
- Open heart surgery within the first few days of life
What is coarctation of the aorta
congenital narrowing of the descending aorta
Give 4 conditions associated with coarctation of the aorta
- Turner’s syndrome
- bicuspid aortic valve
- berry aneurysms
- neurofibromatosis
Is coarctation of the aorta more common in males or females
males
Describe the presentation of coarctation of the aorta
- infancy: heart failure - acute circulatory collapse at 2 days of age when the duct closes
- adult: hypertension, Notching of the inferior border of the ribs
Findings indicative of coarctation of the aorta on examination
- radio-femoral delay (weakened femoral pulse)
- mid ejection systolic murmur, heard under left clavicle and over the back
- apical click from the aortic valve
How is coarctation of the aorta managed
- immediate administration of IV prostaglandins to allow adequate circulation
- definitive - corrective surgery
