12. 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 = PDA
Over time, a large shunt results in left heart enlargement, pulmonary artery hypertension, and 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
Bounding peripheral pulses with a wide pulse pressure
What is a DDx for suspected PDA?
Absence pulmonary valve syndrome Acute anaemia Aortic regurgitation Atrioventricular malformation Bacteraemia and sepsis Bronchial pulmonary artery stenosis Mitral regurgitation
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?
Shortness of breath, especially when exercising
Fatigue
Swelling of legs, feet or abdomen
Heart palpitations or skipped beats
Stroke
What is a DDx for suspected ASD?
Ostium Primum Atrial Septal Defects
Ostium Secundum Atrial Septal Defects
Pediatric Partial and Intermediate Atrioventricular Septal Defects
Pediatric Patent Foramen Ovale Atrial Septal Defects
Sinus Venosus Atrial Septal Defects
Valvar Pulmonary Stenosis
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
How does VSD present?
SMALL = blood shunt minimal, asymptomatic
MODERATE = congestive HF, arrhythmias
LARGE = cyanosis, early HF, severe pulmonary HTN
EXAM = undernourished, sweating, breathing diff, clubbing, tachypnoea, tachy, thrills, precordial palpitation, murmur
What is a DDx for suspected VSD?
Mitral regurg
Tricuspid regurg
ASD
PDA
PS
ToF
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)
What is a DDx for suspected ToF?
Other cyanotic CHD:
- Critical PS
- Transposition of the Great Arteries (TGA)
- Totally anomalous pulmonary venous drainage (TAPVD)
- Hypoplastic left heart syndrome (HLHS)
Isolated VSD
Sepsis
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
What is a DDx for suspected transposition of the great arteries?
ToF = diff from TGA by CXR (boot-shaped heart), ECHO
Tricuspid atresia = diff from TGA by ECG (L axis deviation)
