Cardiology Flashcards
Name the main differences in foetal circulation as compared to adult circulation
- Patent ductus arteriosus creates movement of blood from PA to aorta to bypass fluid filled lungs
- IVC goes straight through R atrium and through foramen ovale to L atrium to again bypass pulmonary circulation.
Left to right shunt complications
Abnormal mixing of blood from left side of the heart (red blood) to right side (blue blood)
Can lead to volume overload and heart failure. Pulmonary hypertension can develop/ hepatosplenomegaly. Eisenmengers is end-stage complication of this (pulmonary hypertension causing eventual right to left cyanotic shunt).
Often present breathless!
What kind of shunt and murmur does a VSD cause?
Left to right shunt- can lead to heart failure. This is the most common CHD (15-20%)
LLSE murmur (might not be heard if VSD is very large)
What is the most common CHD in Down’s?
AVSD. 50% of Down’s babies will have some form of heart defect.
What is the most common CHD in Turner’s Syndrome and what clinical sign may they have?
Coarctation of the aorta
Absent femorals
Pre and post ductal sats are different
What kind of murmur do you often see in PDA?
Machine hum murmur
Left to right shunt
How do you treat a PDA?
It is abnormal over a month old.
Treat with NSAIDS e.g. indomethacin/ ibuprofen until ligation surgery.
What clinical signs might you see in PDA?
Often asymptomatic
Bounding pulses
Poor weight gain
Breathlessness
Can cause HF as left of heart is receiving twice as much as it should.
Name features of AVSD
- Left to right shunt
- Five leaflet AV valve
- Can be cyanosed
- More likely heart failure from overload
Murmur and heart sounds heart in ASD
- Systolic murmur (ULSE) due to increased pulmonary blood flow.
- Fixed split S2 (S2 is closing of semilunar pulmonary and aortic valves). Sounds like Lub b’dub
- Left to right shunt
Describe a right to left shunt and how do they present?
Deoxygenated blue blood is mixing from the right side of the heart is mixing with oxygenated red blood from the left side of the heart, decreasing it’s overall oxygen concentration.
The child therefore appears cyanosed!
What happens in transposition of the great arteries (TGA)?
-Aorta attached to RV
-Pulmonary artery attached to LV
Blue blood returns from body and is pumped back around the body
Needs ‘abnormal’ connection between left and right to mix blood therefore often are duct-dependant
How do you treat TGA?
Prostin needed to keep duct open until surgery. If this doesn’t work an atrial septostomy is performed to buy time before surgical repair.
What congenital syndrome is associated with Tetralogy of fallot?
DiGeorge (2q11 deletion)
Name the four abnormalities in tetralogy of fallot and what murmur do you get?
- VSD
- Overriding aorta
- Subpulmonary stenosis
- Right ventricular hypertrophy
Harsh murmur due to VSD
What are duct dependent lesions?
Lesions that are dependant on the Ductus Arteriousus to maintain systemic perfusion eg due to outflow tract obstruction within the heart. Typically present cyanotic and shocked when the duct closes up hours to days after birth.
Signs and features of coarctation of the aorta?
Outflow obstruction so may hear systolic murmur
Weak/ absent femorals
They depend on the PDA and so become shocked when the PDA closes.
CHD causes of cyanosis:
Cyanosis can be caused by abnormal mixing of blue and red blood, or because the ductus arteriosus has closed and there is an obstructive lesion that was dependant on the blood flow through the ductus arteriousus into the pulmonary arteries.
Some causes of cyanosis (at least duct-dependant but may have e.g. VSD, ASD that enable right to left shunt also): Pulmonary atresia, Tricuspid atresia, Ebstein’s anomaly, hypoplastic left heart, interrupted aortic arch.
Features of an innocent murmur (7 signs):
-Soft
-Short
-Symptom-free
-Systolic
-Site – heard over small area
-Sitting and standing – murmur changes with changes of
position (decreases in intensity when patient stands)
-Signs – none present
Special tests – radiograph, ECG normal
Aortic region murmur (URSE):
Aortic stenosis: Ejection systolic
Pulmonary region murmurs (ULSE):
- Pulmonary flow murmur (ESM)
- Pulmonary stenosis (ESM)
- ASD (actually murmur due to increased flow through pulmonary valve)
- PDA (Continuous)
Tricuspid region murmurs:
- VSD (pan systolic murmur)
- Aortic regurgitation (early diastolic murmur)
- Tricuspid regurgitation (pansystolic murmur)
- Still’s murmur (musical/ vibratory innocent murmur)
Mitral region murmurs:
Mitral regurgitation (Pansystolic murmur) Mitral stenosis (Mid diastolic murmur)
What are tet spells?
Peak incidence between 2-4 months of life with:
- Paroxysm of hypernoea= rapid, deep respiration. Due to increased R to L shunting, CO2 accumulates stimulating the central resp centre. This causes further R to L shunting perpetuating the hypoxia
- Irritability
- Increasing cyanosis
May be precipitated by dehydration, anaemia or prolonged crying induces tachycardia and reduced systemic vascular resistance.
Describe the severities of TOF:
Mild: “pink TOF” often asymptomatic and present age 1-3 as heart gets bigger
Mod: Present in first few weeks of life with cyanosis and respiratory distress. Can develop recurrent chest infections and failure to thrive.
Severe: Present in first few hours of life with marked resp distress and cyanosis.
What do you do if you think the murmur you hear could be pathological?
- Refer to cardiology for ECHO.
- ECG
