Cardiology Flashcards
Physiological circulatory changes at birth
In fetus:
Ductus venosus passes blood from umbilical vein to IVC, by-passing liver
Lungs are fluid-filled and non-functioning -> High RA pressure
Blood pass through Foramen ovale to LA, by passing lungs
Blood pass through Ductus Arteriosus from PA to Aorta, by passing lungs
After birth: With first breath, pulmonary pressure drops and increased blood flow to lungs and blood return to LA LA pressure rises > RA Foramen ovale closes Ductus arteriosus closes
Prevalence of CHD
0.8%
Most common birth defect
Classification of CHD
Left-to-Right shunts/Acyanotic
Right-to-Left shunts/Cyanotic
Obstructive valvular and non-valvular lesions
Types of presentation of CHD
Antenatal diagnosis Murmur Cyanosis - RtoL shunts Heart failure - LtoR shunts, obstructive Shock - obstructive
Clinical features of innocent murmur
aSymptomatic
Soft blowing murmur
Systolic murmur only
left Sternal edge
Normal heart sounds with no added sounds
No parasternal thrill
No radiation
Clinical features of heart failure
Breathlessness
Sweating
Poor feeding
Recurrent chest infections
Poor weight gain Tachypnoea Tachycardia Murmur, gallop rhythm Enlarged heart Hepatomegaly Cool peripheries
Causes of heart failure
Neonates:
Obstructed systemic circulation
If severe have duct-dependent circulation - Sudden deterioration on day 1-2 when duct closes
Infants:
Left-to-Right shunts - left sided HF
Older children:
Eisenmenger Syndrome - right sided HF, due to development of irreversibly raised pulmonary vascular resistance from chronically raised pulmonary blood flow, causing shunt shift from R to Left
Types of Left-to-Right shunts
Atrial septal defect
Ventricular septal defect
Persistent ductus arteriosus
Types of ASD
Secundum ASD
Atrioventricular septal defect
Pathophysiology of each type of ASD
Secundum ASD:
defect in atrial septum involving Foramen ovale
AVSD:
Defect in atrioventricular septum
Interatrial communication bw bottom end of atrial septum and AV valves (primum ASD)
WithMitral regurgitation
Clinical features of ASD
Asymptomatic
Recurrent chest infections/wheeze
Arrhythmias (in 40s)
Ejection systolic murmur at upper left sternal edge (increased flow in pulmonary valve)
Pansystolic murmur at apex - AVSD
Investigations for ASD
CXR: cardiomegaly, enlarged pulmonary arteries
ECG:
Secundum ASD - RBBB, RAD
AVSD - ‘superior’ QRS axis,
Echo with Doppler uss
Management of ASD
Severe secundum (R Ventricle dilatation): cardiac catheterisation with insertion of occlusion device at 3-5 years AVSD: surgical correction af 3 years
Prevalence of VSD
30% of CHD
Most common type
Classification of VSD
Small: defect smaller than aortic valve diameter
Large: defect same of larger than aortic valve diameter
Clinical features of small VSD
Asymptomatic
Loud pansystolic murmur at LLSE
Management of small VSD
None - Closes spontaneously
Clinical features of large VSD
Heart failure: breathlessness, faltering growth, recurrent chest infections Tachypnoea, tachycardia, hepatomegaly Active precordium Loud P2 Soft pansystolic murmur LLSE
Management of Large VSD
Diuretics
Captopril
Additional calorie input
Surgery at 3-6 months
Define patent ductus arteriosus
Ductus arteriosus failed to close by 1 month after expected date of delivery
Clinical features of PDA
Continuous murmur ULSE
Bounding pulse
Management of PDA
Closure with coil or occlusion device by cardiac catheterisation
Surgical ligation
Types of right-to-left shunts
Tetralogy of fallot
Transposition of great arteries
Causes of cyanosis of newborn
Cyanotic CHD
Respiratory: RDS, meconium aspiration, pulmonary hypoplasia
Persistent pulmonary hypertension of newborn
Infection
Inborn error of metabolism
