Congenital heart diseases Flashcards
What is the blood shunting difference b/w acyanotic and cyanotic heart disease ?
Acynotic has left to right shunt. Whereas, cyanotic has right to left shunt.
What is the pathophysiology of ASD ?
An atrial septal defect occurs when there is a failure to close the communication between the right and left atria.
What are the types of atrial septal defects?
There are five types of atrial septal defects and that include:
*patent foramen ovale
*ostium secundum defect
*ostium primum defect
*sinus venosus defect
*coronary sinus defect
What are the genetic causes of ASDs ?
Down syndrome, Treacher-Collins syndrome, Thrombocytopenia-absent radii syndrome, Turner syndrome, and Noonan syndrome.
What are the non-genetic causes of ASDs?
Maternal exposure to rubella and drugs, such as cocaine and alcohol.
What is the shunting evolution in ASD and Eisenmenger syndrome ?
ASD has initially a left to right shunt due to increased pressure in left atrium as compared to the right. However, over time the excessive flow of blood through the pulmonary arteries from the right ventricle will lead to PHNT. This will result in shut shifting from right to left known as Eisenmenger syndrome.
What are the symptoms in ASD?
It is initially asymptomatic and when the shunt shifts the symptoms such as SOBOE, fatigue and recurrent LRTI develops.
What are the auscultatory findings in ASD?
- Wide fixed split S2 and a grade 2 to 3/6 midsystolic murmur best heard at the left upper sternal border.
What are the other findings in ASD ?
– CXR (increased pulmonary vascular markings)
– ECG (Rt axis deviation, RVH)
– ECHO (demonstrates the shunt w/Doppler)
– Rt heart catheterisation (can measure O2 saturation)
What is the goal of ASD Tx ?
Goal is prevention of pulmonary vascular disease
or HF
What are the Tx in ASD ?
- ASDs of <5-8mm, will likely spontaneously resolve.
- Precutaenous septal occlusion
- Direct suture closer.
- Monitor for return of normal RA/RV morphology
- Antibiotic prophylaxis for dental procedures &
surgery
What is the pathophysiology of PDA ?
The patency of the ductus is promoted by prostaglandin E2.A PDA can result in blood flowing from the descending aorta across the patent ductus arteriosus into the pulmonary circulation (“left-to-right”). The magnitude of the right to left shunt depends on the ratio of the pulmonary vascular resistance (PVR) to the systemic vascular resistance (SVR). If the PVR is low and the SVR is high, the flow through the shunt to the lungs will be high and vice versa. when the shunt reverse it will result in Eisenmenger syndrome marked by lower extremity cyanosis & clubbing.
What are the complications of PDA?
pulmonary edema and pulmonary hemorrhage, necrotizing enterocolitis, intraventricular hemorrhage, congestive heart failure, renal failure, and bronchopulmonary dysplasia (BPD)
What is the Tx of PDA ?
- Prostaglandin synthesis inhibitor such as Indomethacin or ibuprofen.
- If persistently open after medical
tx, then surgical division or ligation
is an option.
Risk factors for PDA ?
Infants born weighing less than 1000 grams are at the highest risk for PDA. In this population, 70% will have a PDA on day 7.
What is the murmur of PDA ?
The classic PDA murmur is a continuous, “machinery” murmur below the clavicle, radiating to the back.
What are the physical examination findings in PDA?
- a prominent precordial impulse, tachycardia, and bounding peripheral pulses due to increased cardiac output.
- Hypotension is most prominent in infants < 1000g grams.
- A widened pulse pressure (> 30mmHg).
What is the pathophysiology of coarctation of the aorta?
It is narrowing of the aorta which can occur Juxtaductal, postductal and preductal. This will lead to increased upper extremity BP (HTN) and reduced lower extremity BP and radiofemoral delay.
Risk factors of CA ?
Turner syndorme and Bicusped aortic valave.
What is the clinical presentation of CA ?
- Severe obstruction has immediate effects
on newborn - Preductal has differential cyanosis
- Most are asx
- Elevated upper extremity BPs
- Femoral pulses = weak, delayed
- Mid-systolic murmur over chest & back
What are signs of CA?
- Rib notching below the coarctation due to dilated posterior intercostal arteries that are feeding to the distal aorta.
What are the work-ups in CA?
CXR may show inferior rib notching &
possibly an indented descending aorta (‘3 sign’)
– ECHO confirms lesion and assesses pressure gradient
What are the Tx of CA?
– Severe: prostaglandins to keep CA open
– Excision & re-anastomosis
– Balloon +/- stenting
What are the risk factors for VSD?
– Foetal alcohol syndrome
– Down syndrome (trisomy 21)
What is the relationship b/w murmur and VSD size ?
The harsh pan-systolic best heard in the left lower sternal border will be loud in small VSD and soft in large VSD.
What is the Tx of VSD ?
- Approximately half of all VSDs
heal spontaneously by 2yoa - Closure indicated w/signs or sxs
of CHF or pulmonary vascular
disease - Large VSDs left untreated have
high risk for IE - Open vs percutaneous approach
What is the pathophysiology of aortic stenosis ?
It is more common in Males than females.The most common cause is bicusped aortic valve. Higher force required to eject blood from LV causes LVH and powerful jets causes aortic root dilatation.
What is the clinical presentation of aortic stenosis ?
– Most asx, If sx, similar to adults with acquired AS.
– Harsh crescendo-decrescendo murmur which is Loudest at base, radiates to neck.
what are the work-ups in aortic stenosis ?
– ECHO for assessment of pressure
gradient & calculation of valve area
– Cardiac cath confirms pressure gradient
What is the Tx of aortic stenosis ?
– Balloon valvuloplasty
– Surgical revision or replacement
What is the pathophysiology of pulmonary stenosis ?
Abnormal development of the valve,
outflow tract, or the pulmonary artery causes Valve stenosis leading to Increased RV pressures and RVH . The Disease measured by transvalvular gradient.
What are the ausculatory findings in PS ?
– Prominent jugular venous a wave
– RV heave & thrill
– Widely split S2, soft P2
– Ejection click
– Loud, late-peaking, crescendodecrescendo systolic murmur at upper LSB.
What are the clinical presentations in PS?
- Distended neck veins
(elevated JVP) - Hepatosplenomegaly
- Lower ext oedema
What are the work-up findings in PS ?
– ECG = RAD/E, RVH
– Labs:
* Microangiopathic haemolytic
anaemia (schistocytes)
* Haemoglobinuria
– ECHO to confirm, assess
pressure gradient
What is the Transvalvular Gradient and Disease Severity of PS ?
Mild < 50 mm Hg
Moderate 50 - 80 mm Hg
Severe > 80 mm Hg
What is the Tx of PS ?
– Moderate or severe:
transcatheter balloon
valvuloplasty
– Usually followed by
regression of RV hypertrophy
What is the pathophysiology of Tetralogy of Fallot ?
- VSD
- (Subvalvular) Pulmonic stenosis
- RVH
- Overriding aorta
Right to Left Shunt causing Cyanosis
What is ‘ tet spell ‘ in ToF ?
It is the squatting positioning of the cyanotic child to increase after load to perfuse the systems.
What is the CXR sign of ToF ?
Boot shaped heart.
What is the Tx of ToF ?
– Temporary measure = create
connection b/t aorta & PA
– Surgical repair involves closure of
VSD & enlargement of
subpulmonary infundibulum
– Successful repair usually results in
asx adults
