Congenital cardiac defects PPT (0/16)

PDA definition, risk factors and treatment in relation to pathophys

Patent (open) ductus arteriosus fails to close AFTER BIRTH, causing too much blood to flow in the lungs due to shunt/bypass.

Risk factors: prematurity, PPHN (pulm. hypertension) and resp. distress.
Treatment: NSAIDS, Tylenol, surgical closure, left alone if key to survival

PFO and ASD

Both are holes b/w atriums that are supposed to be closed. PFO relates to patent formane ovale that should close after birth (shunts LA → RA), and ASD is hole in septum.

VSD

Ventricular septal defect

Hole in septum b/w RV + LV and can range in size (larger being more symptomatic like causing a L→R shunt).

L sided obstructive lesions (3)

1. ASD

2. coarctation of aorta

3. HLHS

ASD

Aortic septal defect

hole b/w RA and LA → L→R shunt → hyperperfusion + hypertension
Treatments: mech vent., PDA w/ PGE1, surgical repair

Coarctation of aorta

Increased resistance/narrowing (aka coarctation) of aorta = lowered perfusion

Clinical manifestations: cardiomegaly, pulm. congestion, higher BP in upper extremities but weak pedal pulses

Treatment: emergent opening of PDA, surgical repair

HLHS

Hypoplastic left heart syndrome

Underdeveloped/hypoplastic L-heart structures w/ BF relying on foramen ovale + ductus arteriosus to remain OPEN. If not, hypoperfusion, met. acidosis, circulatory collapse and death. can happen.

TOF

Tetra(4)logy of Fallot

Baby can turn into a “spell” (hyperpnea (low BF + DS = turn blue), irritability, loss of consciousness). It is a combo of 4 cardiac issues:

1. pulmonary artery stenosis (pulm. narrowing)

2. ventricular septal defect (hole b/w ventricles)

3. overriding aorta (displaced over ventricles receiving BF from both sides)

4. right ventricular hypertrophy (increase pressure = thick RV)

Truncus arteriosus

RARE. Instead of having an aorta and pulmonary arteries, a SINGULAR artery supplies both systemic and pulmonary circulations.

Transposition of great arteries

Great arteries are “transposed”/changed when cord is clamped:

1. RV → aorta (O2 poor → body)

2. LV → PA (O2 rich → lungs)

These work in parallel unless a shunt occurs, meaning deoxygenated blood will only go to the body, and rich blood will only go to the lungs.

Cyanotic vs acyanotic

1. Cyanotic:

   1. systemic O2: decreased

   2. shunt: R→L (poor O2 circulates systemically)

      1. TTT! TOF, transposition of great arteries, truncus arteriosus

2. Acyanotic:

   1. Systemic O2: normal

   2. shunt: L→R = too much blood to lungs

      1. VSD, ASD, PDA, coarctation of aorta

Acyanotic lesions

1. PDA

2. ASD

3. VSD

When to keep the ductus arteriosus open (3)

When baby dependent on it for:

1. systemically BF: HLHS, coarctation, ASD

2. pulmonary BF: severe TOF

3. when closure could cause hypoperfusion or hypoxemia

What is a ductal dependent defect?

When O2 rich systemic circulation or to lungs is dependent on BF through ductus arteriosus if part of heart is obstructed.

How is the ductus arteriosus closed (3)

1. Functional closure: smooth muscle constricts and stops or slows BF when O2 increases + prostaglandins decrease

2. Anatomic closure: fibrotic remodeling sealing

3. Artificial closure: NSAIDs, surgery, or catheter-based closure.

How to keep the ductus arteriosus open

PGE1. it relaxes smooth muscle to open/reopen and is given as continuous IV infusion.