Paeds Cardio Flashcards
1
Q
What is tetralogy of fallot and its 4 features ?
A
- key issue: interior dislocation of the septum which partially obstructs RVOT and PA
1. ventricular septal defect: leading to equal ventricular pressures
2. pulmonary stenosis
3. overriding aorta
4. RV hypertrophy
2
Q
What is the pathophysiology of a VSD and overriding aorta in tetralogy of fallot?
A
- VSD allows blood to flow between ventricles
- overriding aorta: aortic valve is above VSD allowing deoxygenated blood into aorta
3
Q
What does stenosis of the pulmonary valve in tetralogy of fallot cause?
A
- greater resistance against blood flow from RV
- encourages blood to flow through VSD and into aorta
- causing R to L shunt and cyanosis
4
Q
Why is there RV hypertrophy in tetralogy of fallot?
A
- inc muscular strain on RV
- trying to pump blood against resistance of LV
- causes RV hypertrophy and thickening of heart muscle
5
Q
How is cyanosis caused in tetralogy of fallot?
A
- all factors cause R to L cardiac shunt
- blood bypasses lungs and is not oxygenated
- deoxygenated enters systemic circulation
- causes cyanosis
6
Q
What is the presentation of tetralogy of fallot?
A
- cyanosis
- clubbing
- dyspnoea on feeding, crying, exertion
- Tet spells: sudden onset dyspnoea/cyanosis
7
Q
What are the heart sounds in Tetralogy of Fallot?
A
- ejection systolic murmur
- heard loudest in pulmonary area: 2nd intercostal space on left sternal border
8
Q
What are risk factors for Tetralogy of Fallot?
A
- rubella
- age of mother >40
- alcohol in pregnancy
- diabetic mother
9
Q
What investigations are done for tetralogy of fallot and what is seen?
A
- echocardiogram
- doppler flow studies
- boot shaped heart due to RV thickening
10
Q
What is the pathophysiology of a Tet spell?
A
- intermittent symptomatic period where R to L shunt gets worse
- occurs when pulmonary vascular resistance inc or systemic resistance dec
- blood going from RV to aorta and bypassing pulmonary vessels
11
Q
What is the presentation of a Tet spell?
A
- waking, crying
- irritability, cyanosis, SOB
- Severe: reduced consciousness and seizures
12
Q
How is a Tet spell treated?
A
- older children squat
- younger: knees to chest
- increases systemic resistance
- supplementary oxygen
- β blockers
- IV fluids
13
Q
How is tetralogy of fallot managed surgically?
A
- VSD patched
- PV widened or replaced
- neonates: prostaglandin infusion to maintain ductus arteriosus
14
Q
What is a ventricular septal defect?
A
- most common form of congenital heart disease
- malformation of ventricular septum
- if LV pressure > RV then blood flows LV to RV
- inc blood flow through lungs
15
Q
Why are patients acyanotic in VSD?
A
- blood flows L to R and flows around the lungs again
- therefore blood is oxygenated
- L to R shunt causes R side overload
- R heart failure and inc flow into pulmonary vessels
16
Q
What is Eisenmenger syndrome?
A
- inc blood in RV > inc pulmonary > pulmonary hypertension
- causes R to L shunt due to inc pressure in R side
- patient becomes cyanotic as blood is bypassing lungs
17
Q
What genetic conditions is a VSD associated with?
A
- Down’s syndrome
- Turner’s syndrome
18
Q
How does a VSD present on examination?
A
- pan systolic murmur at left lower sternal border
- in 3rd-4th intercostal spaces
- systolic thrill on palpation
19
Q
How does a VSD present?
A
- poor feeding
- dyspnoea
- tachypnoea
- failure to thrive
- can be symptomless and present in adulthood
20
Q
How is a VSD diagnosed?
A
- gold standard: echocardiogram
- CXR, ECG
21
Q
How is a VSD managed?
A
- small VSDs can close spontaneously
- transvenous catheter closure via femoral vein
- percutaneous/open heart surgery, patch application
- risk of infective endocarditis: Abx prophylaxis
22
Q
What is an atrial septal defect?
A
- congenital heart defect causing a shunting of blood from L to R atria
- inc flow into right heart and lungs
- secundum ASD: patent foramen ovale
- leads to right heart dilation in severe
23
Q
What is the pathophysiology of an ASD?
A
- defect in the endocardial cushion leads to ASD
- leads to shunt from L to R atrium
- blood flows through PV and lungs
- inc flow causes R sided overload and strain
- can lead to R side HF
24
Q
What are complications of ASD?
A
- stroke (VTE)
- AF
- pulmonary hypertension
- eisenmenger syndrome
25
How does an ASD present on examination?
- mid-systolic, crescendo-descendo murmur
- loudest at upper left sternal border
- pulmonary flow murmur
- fixed split S2 heart sound as PV and aortic valve close at diff times
26
How does ASD present?
- SOB
- difficulty feeding
- poor weight gain
- LRTI
27
How is ASD managed?
- transvenous catheter closure
- open heart surgery
- anticoags to dec risk of clot and stroke
28
What is an atrio-ventricular septal defect (AVSD)?
- Involves the ventricular septum, the atrial septum, the mitral and tricuspid valves
- Can be complete or partial
29
What is a patent ductus arteriosus (PDA)?
- Persistence of the connection between the aorta and pulmonary artery
- normally rise in PaO2 and decline in prostaglandins close the duct
30
What is the pathophysiology of a PDA?
- pressure in aorta higher than pulmonary vessels
- creates L to R shunt
- blood flows from aorta to PA
- leads to pulmonary hypertension, R heart strain, RV hypertrophy
- inc blood flow > LV hypertrophy
31
How does a patent ductus arteriosus present?
- tachycardia and tachypnoea
- SOB
- difficulty feeding
- poor weight gain
- LRTI
32
How does a PDA present on examination?
- continuous crescendo-descendo murmur
- machinery murmur
- 2nd heart sound difficult to hear
33
How is PDA diagnosed and managed?
- diagnosis: echocardiogram
- medical: preterm: indomethacin, ibuprofen, paracetamol
- management: usually closed via cardiac catheterisation
34
Why are paracetamol/ibuprofen given in PDA?
- prostaglandin inhibition
- promotes duct closure
35
What is coarctation of the aorta and how does this present in severe and mild patients?
- narrowing of the aorta at the site of the ductus arteriosus
- presents with htn and murmur
36
How does coarctation of the aorta present?
- right arm hypertension
- bruits over scapulae and back
- murmur
37
How is coarctation of the aorta managed?
- repaired by surgical or percutaneous intervention - narrow section removed
38
What is transposition of the great arteries?
- where the aorta and pulmonary trunk are swapped
- RV pumps blood into aorta and LV into PA
39
What conditions is transposition of the great arteries associated with?
- VSD
- coarctation of the aorta
- pulmonary stenosis
40
Why is transposition of the great arteries life threatening?
- two circulations don't mix
- baby is cyanosed as deoxygenated blood is going to the body
41
How is transposition of the great arteries diagnosed and how does it present?
- diagnosed in antenatal USS scans
- if undetected, presents with cyanosis at birth
- resp distress, tachycardia
- poor feeding, poor weight gain
42
How is transposition of the great arteries managed with other defects?
- if VSD, this allows time for treatment
- prostaglandin infusion maintains ductus arteriosus
- balloon septostomy to create larger ASD
43
What is the definitive management of transposition of the great arteries?
- open heart surgery
- cardiopulmonary bypass machine
- perform arterial switch
