Congenital Heart Diseases Flashcards
1
Q
ventricular septal defect (VSD)
A
left-to-right shunt
- result in wide splitting of S2 due to increased right ventricular volume causing delayed closure of the pulmonary valve
- abnormal increase in oxygen saturation (SpO2) between the right atrium and the right ventricle
- With smaller VSDs, blood is shunted mainly from left to right due to the high pressure differential between the ventricles
- As a result, right ventricular SpO2 increases but left ventricular SpO2 remains relatively normal.
- Larger VSDs allow equalization of chamber pressures, which results in more bidirectional mixing and decreased left ventricular SpO2
- Right atrial SpO2 remains normal with VSDs of any size, unless tricuspid regurgitation is also present.
- Turbulent blood flow across a small VSD produces a loud holosystolic murmur best heard over the lower left sternal border.
- This murmur may be absent in larger (nonrestrictive) VSDs due to decreased resistance across the VSD and a lower trans-septal pressure gradient.
2
Q
hypertrophic cardiomyopathy,
A
bifid carotid pulse with brisk upstroke (“spike-and-dome”)
- condition with dynamic left ventricular outflow tract obstruction during systole
- SpO2 in the cardiac chambers remains normal.
3
Q
patent ductus arteriosus
A
precordial continuous, machine-like murmur
- produces isolated pulmonary artery SpO2 elevation.
4
Q
coarctation of the aorta,
A
decreased femoral-to-brachial blood pressure ratio
5
Q
atrial septal defect (ASD)
A
- Fixed splitting of S2 as equalization of left and right atrial pressures minimizes the respiratory variation in ventricular blood flow.
- causes increased SpO2 in the right atrium compared with the vena cava but identical right atrial and ventricular SpO2.
6
Q
Eisenmenger syndrome
A
Blood flow across the VSD in Eisenmenger syndrome is right to left due to elevated pulmonary vascular resistance, resulting in decreased SpO2 in the left ventricle.
