c) Over time PVR to that of SVR i) reverses shunt (cyanosis) 2.- R to L shunt a) pulmonary blood flow i) Cyanosis “blueness” of skin b) examples: i) tetralogy of Fallot ii) great vessel transposition iii) truncus arteriosus iv) tricuspid atresia v) anomalous pulmonary venous connection
c) long standing cyanosis is associated with “clubbing” of the tips of the fingers and toes
3.- Obstructions (of flow) a) coarctation of the aorta b) valvular stenosis i) aortic ii) pulmonary c) complete obstruction is called “Atresia”
i) VSD most common - close spontaneously (50%) ii) ASD usually not symptomatic before 30 yrs
iii) DA remains open after birth - ~ 90% occur as isolated anomaly - reversal of flow with PVR causes cyanosis - PGE will maintain DA cardiac defects such as obstructive disease iv) complete atrioventricular canal defect - all 4 chambers freely communicate (Down syndrome)
Clinical Presentation: a) Cyanosis is almost always present at birth and is progressive.
b) Etiology/Pathophysiology: i) Due to absence of the tricuspid valve. This leads to an interatrial right to left shunt, usually through a patent foramen ovale.
ii) It is classified by the absence of tricuspid valve, pulmonary stenosis, and VSD. iii) The most Common form is also associated With a hypoplastic right ventricle
TRICUSPID ATRESIA 1 - atrial septal defect 2 - absent tricuspid valve 3 - ventricular septal defect Blood is shunted through an atrial septal defect to the left atrium and through the ventricular septal defect to the pulmonary artery. The shaded arrows indicate mixing of the blood.
Total Anomalous Pulmonary Venous Connection (TAPVC)
No pulmonary veins directly join LA
a) drain into left innominate vein or coronary sinus
b) PV drain into RA
ASD or foramen ovale always present
a) allows PV blood to enter LA
b) R to L shunt
Volume and pressure hypertrophy of RV
1 - superior vena cava 2 - atrial septal defect 3 - left innominate vein 4 - pulmonary veins Oxygenated blood returning from the lungs is routed back into the superior vena cava, rather than the left atrium. The presence of an atrial septal defect is necessary to allow partially oxygenated blood to reach the left side of the heart. Total Anomalous Pulmonary Venous Connection (TAPVC)
1 - pinched or coarcted aorta flow patterns are normal but are reduced below the coarctation. Blood pressure is increased in vessels leaving the aorta above the coarctation. The broken white arrow indicates diminished blood flow through the aorta.
ii) when Left heart failure is present, hypoxic liver shows signs of “centrilobular necrosis” iii) long standing Right failure - cardiac cirrhosis iv) portal hypertension - congestive splenomegaly v) ascites vi) pleural and pericardial effusions accompany Right heart failure