148 CHD II

Question 1

3 varieties of CHD

Answer 1

–Shunts: abnormal communication between 2 structures (cardiac chambers, blood vessels)

–Cyanosis: desaturation that can result from 3 basic types of structural problems

–Severe obstruction: presentations unique to congenital heart disease

Question 2

•pulmonary overcirculation

Answer 2

Question 3

Indications of shunts in fetal clinical presentation

Answer 3

•Clinical picture: tachypnea, intercostal & subcostal retractions (“tugging“)

–More difficult to feed – drop in nutritional intake

–Higher respiratory effort – calories not available for growth

–“Failure to thrive” due to pulmonary overcirculation – lack of growth

• Infantile failure to thrive – indication for repair
• However, even if growing well in infancy, shunting can produce other longer term complications that could be avoided if we eliminate the shunt

Question 4

Eisenmenger syndrome

Answer 4

•Eisenmenger syndrome: cyanosis in a lesion that would normally result in left-to-right shunting, resulting from increased PVR “reversing the shunt”

•Eisenmenger syndrome: much lower mortality

–If pulmonary resistance exceeds the capability of the RV, RV blood can cross to the lower resistance LV & systemic circuit

–Right heart blood crossing to left heart drops O2 saturations

–Cardiac output is preserved at the expense of cyanosis

•Cyanosis is better tolerated

Question 5

When to intervene on shunts

Answer 5

Question 6

Qp/Qs

Answer 6

Qp/Qs = (SA sat – SV sat)/ (PV sat – PA sat)

if > 1.5, typically complications if not addressed

Question 7

Pulmonary Vascular Resistance

Answer 7

PVR = ( mean PA pressure - Pulmonary Capillary Wedge Pressure ) / Cardiac Output

R = deltaP x flow

•PVR > 5-7 shows elevated risk with defect closure