Congenital Heart Disease 2

Front 1

With what CHD types do you see a right to left shunt?

Back 1

All the critical ones:
1) inadequate pulmonary blood flow (tetralogy's overriding aorta)
2) inadequate systemic blood flow (coarctation, hypoplastic left heart syndrome)
3) transposition of the great vessels ideally has a bidirectional flow to increase mixing
4) total anomalous pulmonary venous connection, because otherwise nothing gets into the LA

Front 2

What are some clinical manifestations of inadequate pulmonary blood flow?

Back 2

cyanotic, single S2, murmur
No respiratory distress, normal pulses and perfusion
ABG: moderate/marked hypoxemia
CXR: low pulm circulation

Front 3

What's the anatomy in the tetralogy of Fallot?

Back 3

VSD, pulm stenosis, overriding aorta, RV hypertrophy. Causes inadequate pulmonary blood flow.

Front 4

What's the medical management of the tetralogy of Fallot?

Back 4

PGE1 to keep the ductus arteriosus that brings blood flow from aorta to pulm arteries and lungs.
For tet spells: decr pulm vasc resistance (O2, morphine), incr systemic vasc res (knee to chest, incr volume, phenylephrine). sodium bicarbonate for acidosis, bB to decrease contractility and relax infundibulum.

Front 5

What's the surgical management for the tetralogy of Fallot?

Back 5

close VSD with patch and enlarge RV outflow.
Palliative: shunt from aorta to pulm artery (modified Blalock Taussig)-- still have some cyanosis

Front 6

What are the clinical manifestations of inadequate systemic blood flow?

Back 6

gray/ashen, tachypnea, decr/differential pulses, poor perfusion, single S2, murmur, sometimes gallop, RV heave, hepatomegaly.
ABG: met acidosis, hypoxemia.
CXR: large heart, incr pulm blood flow

Front 7

What is the anatomy of a coarctation of the aorta?

Back 7

usually juxtaductal, discrete (shelf) or tubular hypoplasia blocks blood flow, 80 % have a bicuspid aortic valve. ductus arteriosus allows blood to bypass and to shunt from the pulmonary artery in systole. Inadequate systemic blood flow.

Front 8

What's the medical management of coarctation of the aorta?

Back 8

prostaglandin E1 to reopen ductus
inotropic support (esp w/ LV dysfxn)
diuretic therapy (furosemide) for congestion
Usually just used to stabilize for surgery.

Front 9

What's the surgical management of coarctation of the aorta?

Back 9

Subclavian flap repair: take subclavian vein, make a flap, enlarge the aorta. Best if < 1yo.
Resection w/ end to end anastomosis
Patch angioplasty: elliptical prosthetic patch inserted to enlarge the aorta, for tubular hypoplasia.
Balloon dilation: long-term efficacy is uncertain, procedure of choice for recurrent coarctation.

Front 10

What's the anatomy of hypoplastic Left Heart syndrome?

Back 10

hypoplastic/stenotic/atretic aortic valve, mitral valve and LV. pulm venous blood enters RA by ASD or PFO, RV pumps to lungs and body, ductus arteriosus is the only source of blood to the descending and ascending aorta. Inadequate systemic blood flow.

Front 11

What's the medical management for Hypoplastic left heart syndrome?

Back 11

prostaglandin E1
if too little systemic circulation, you need to incr pulm resistance (CO2) or decrease vascular resistance (nitroprusside). Always avoid decreasing pulm resistance (O2, hyperventilation) and increasing systemic resistance (pressors).

Front 12

What's the surgical management for hypoplastic left heart syndrome?

Back 12

Stage I Norwood: to decr pulm blood flow, allow LA-RA flow, unobstruct systemic blood flow.
make neo-aorta with pulmonary artery homograft. place pulm artery shunt to control pulm blood flow. ligate PDA and resect atrial setpum.
Stage 2: Hemifontan (6 mo old) (replace shunt to connect to upper body)
Stage 3: Fontan (1 yo)
70-80 % survival of all 3 procedures.

Front 13

What are the clinical manifestations of Inadequate Mixing lesions?

Back 13

cyanosis, mild tachypnea, normal puse and perfusion, single S2, murmur.
ABG: marked hypoxemia, maybe acidosis.
CXR: nml/large heart, incr pulm blood, narrow mediastinum

Front 14

What's the anatomy for d-transposition of the great arteries?

Back 14

RV --> aorta --> RA.
LV --> pulm artery --> LA.
parallel great vessels, aorta is anterior and right. VSD, ASD or PDA allow bood to mix (best if PFO or ASD because flow is bidirectional).
Inadequate mixing lesion.

Front 15

What's the medical management for a transposition of the great arteries?

Back 15

PGE1 is controversial, because shunts mostly from aorta to PA and so doesn't increase O2 in body. It may also increase blood in RA and so close the PFO-- maybe more useful with larger VSD.

Front 16

What's the surgical management for a transposition of the great arteries?

Back 16

palliation: balloon atrial septostomy to enlarge the ASD
Arterial Switch procedure: cut and switch great vessels, move coronary arteries. 5 % mortality, do in first days of life.
Alternative: Switch flows at the atrial level: RA to LV to lung, LA to RV to aorta to body, use pericardium or atrial septum. 2% mortality but later comps (Afib, obstructive venous return, RV dysfxn)

Front 17

What are the manifestations of a poor gas exchange defect?

Back 17

cyanosis, marked tachypnea, fair perfusion, normal pulse, split S2 with loud P2 or single S2, maybe a murmur.
ABG: mild to marked hypoxemia, acidosis
CXR: normal, small heart, pulm venous congestion, abnormal venous channels.

Front 18

What's the anatomy for Total anomalous pulmonary venous connection (TAPVC)?

Back 18

common pulm vein doesn't drain to LA but instead to:
-a vertical vein that leads to innominate vein or SVC in supracardiac.
-a vertical vein that penetrates the diaphragm and enters the portal/hep if infracardiac.
-a vein that empties into RA or coronary sinus if cardiac.
-multiple strange veins if mixed.
Obligatory ASD or PFO to get blood to LA, many have PDA.
Obstruction leads to congestion and poor gas exchange.

Front 19

What's the medical management of TAPVC?

Back 19

positive pressure ventilation, anti-congestion with diuretics
Avoid PGE1 --> incr pulmonary blood --> incr pulm venous congestion.

Front 20

What's the surgical management for TAPVC?

Back 20

recommended. 8-12% mortality.
incr surgical risk with incr pulm venous obstruction and pulm HTN (so it's better to do it early).
Anastomose the common pulm vein back to LA with the widest possible anastomosis to decrease the obstruction, then close PDA and ASD.