Congenital Heart Disease Flashcards
Outline the pathophysiology of PDA?
At birth, the rise in PaO2 and decline in prostaglandin concentration cause closure of the ductus arteriosus, typically beginning within the first 10 to 15 h of life
This does not happen by 1m = PDA
L to R = aorta to pulmonary A
Over time, a large shunt results in L heart enlargement, pulmonary artery HTN, elevated pulmonary vascular resistance, ultimately leading to Eisenmenger syndrome.
How does PDA present?
HF = failure to thrive, poor feeding, tachypnoea, dyspnoea with feeding, tachycardia
Murmur: CONTINUOUS EJECTION SYSTOLIC - machinery
- upper L sternal edge
Collapsing or bounding peripheral pulses with a wide pulse pressure
Mx =
- Pre-term: spontaneous closure
- Ibuprofen to close, prostaglandin to keep open
- Catheter closure or PDA ligation
Outline the pathophysiology of ASD?
Failure in any stage of the septum primum and septum secundum fusing together
L to R shunt, RV volume overload, Increased pulmonary blood flow, Eventual right heart failure
How does ASD present?
Asymptomatic
- SOB, especially when exercising
- Fatigue
- Swelling of legs, feet or abdomen
- Heart palpitations or skipped beats
- Stroke
- Recurrent chest infections
MURMUR = EJECTION SYSTOLIC, SPLIT 2nd HS
- upper L sternal edge
Mx =
- spontaneous closure if 7-8mm
- via cardiac cath insertion of occlusion device or surgical correction
Outline the pathophysiology of VSD?
L to R shunt, LV volume overload = raised RV pumped out as normal but larger vol returns overloading the L side of the heart
Perimembranous VSD = membranous septum, adjacent to tricuspid valve
Muscular = completely surrounded by muscle
More common than ASD
How does VSD present?
SMALL = blood shunt minimal, asymptomatic
MODERATE = congestive HF, arrhythmias
LARGE = cyanosis, early HF, severe pulmonary HTN, pansystolic murmur or no murmur implying large defect, tachy, tachypnoea, hepatomegaly
Murmur: PANSYSTOLIC
- Lower L sternal edge
EXAM = undernourished, sweating, breathing diff, clubbing, tachypnoea, tachy, thrills, precordial palpitation, murmur
Mx
- small = close spontaneously if <5mm
- furosemide + spironolactone
- high calorie feeds
- large = HF mx, surgery to prevent pulmonary HTN
Outline the pathophysiology of ToF?
PROVe
- Ventricular septal defect (VSD)
- Pulmonary stenosis (PS)
- Right ventricular hypertrophy (RVH)
- Overriding aorta
How does ToF present?
MILD = mild PS/RVH, asymptomatic, heart grows and devel cyanosis by 1-3y
MODERATE-SEVERE = cyanosis, resp distress, recurrent chest infections, failure to thrive
EXTREME = present within the first few hours of life with marked respiratory distress and cyanosis
EXAM = central cyanosis, clubbing, thrill, loud single S2, pansystolic murmur, ejection click, continuous machinery murmur, HF (pallor, tachy, oedema, bilateral basal crackles, gallop rhythm)
Outline the pathophysiology of transposition of the great arteries?
Right Vent connected to Aorta
Left Vent connected to Pulmonary Artery
not viable unless the 2 circuits communicate via: PFO, ASD, VSD, PDA
“ventriculoarterial discordance”, in which the aorta arises from the morphologic right ventricle and the pulmonary artery arises from the morphologic left ventricle
How does transposition of the great arteries present?
Cyanosis - first 24h
Congestive HF - tachypnoea, tachycardia, diaphoresis, and failure to gain weight
Exam:
- Prominent right ventricular heave
- Single second heart sound, loud A2
- Systolic murmur potentially if VSD present
- No signs of respiratory distress
Mx = prostaglandin, balloon atrial septostomy
How does pulmonary and aortic stenosis present?
PULMONARY = crescendo-decrescendo ejection
- Upper L sternal edge
AORTIC = crescendo-decrescendo ejection
- Upper R sternal edge
