Congenital Heart Disease
This is a deliberately brief description of CHD. Echo assessment of anything more complicated than this requires zen master expertise.
ASD
Secundum commonest where fossa ovalis absent.
Primum in inferior septum.
L to R shunt with pulmonary hypertension and R heart failure.
Best seen in subcostal window.
Colour shows flow across.
Assess flow across with PW also.
Look for R sided dilatation and RV volume overload (paradoxical septal motion in diastole).
Assess for pulmonary hypertension.
Perform shunt calculation.
ratio of RV SV to LV SV
For RV SV measure RVOT diameter and PW same spot for VTI.
For LV SV measure LVOT diameter (PLAX) and PW same spot in A5C for VTI.
For PFO get patient to do valsalva and look for right to left flow in A4C and subcostal views.
Perform contrast study (agitated saline) if not sure if ASD or PFO present. If no shunt, micro-bubbles dissipate within the lung vessels and so are not seen the left heart. If the shunt is myocardial will get contrast appearing in the LA within 3 cardiac cycles of RA opacification. An intrapulmonary shunt (eg AV malformation) takes 5 cycles or longer.
Atrial septal aneurysm looks like bulging IAS protruding or moving at least 10mm with a base of at least 15mm.
VSD
Perimembranous
Located in thin fibrous membranous septum just below AV.
PLAX (hole below AV).
Muscular
In the muscular septum. Will be here if the result of an MI. May be multiple.
Inlet (canal, posterior)
Posterior to TV septal leaflet.
A4C.
Subpulmonary (outlet, doubly committed)
In between the outflow tracts just below AV and PV.
PSAX and A5C
Associated AR from RCC prolapse.
Same principles as for ASD.
Small holes will have higher velocities - restrictive VSD.
Shunt calculation.
Velocity of the jet related to pressure by Bernoulli so can calculate ventricular pressure difference.
Look for R heart and LA dilatation.