PDA

Question 1

Incidence

Answer 1

• more in females
• congenital rubella syndrome
• preterm infants

Question 2

Anatomical defect

Answer 2

1- persistence of ductus arteruosis
2- distal to the origin of pt subclavian artery

Question 3

Hemodynamics

Answer 3

During iu life
• there is no lung functioning ~> + pulmonary pressure ~> blood shunting from pulmonary to aorta

After fetal life
• ductus is closed , lung is opened ~> aorta gains pressure , pulmonary loses its high pressure gradually ( thus in the first week there is low pg between rt , lt ~> onset in vsd, pda is in second week of life ) ~> shunting of blood from aorta to pulmonary during both systole , diastole

• lung plethora
• lt artial , ventricular enlargement ( volume overload)

Question 4

Why patent during iu life ? Vice versa

Answer 4

1-hypoxia
They both help in relaxing

2- + pg
3- the only way ( high flow )

Vice versa
1- no hypoxia ( lung is functioning )
2- pg is destroyed by the lungs
3- will not be the only way as lung is opened

Question 5

Closure of ductus

Answer 5

1- functionally with 24 h due what is mentioned before
2- anatomically within weeks by fibrosis

Question 6

Talk about small PDA ( his- exam- inv- ttt)

Answer 6

1- his : asymptomatic
2- exam
General : normal
Cardiac : murmur
- continous ( but higher in systole)
- machinery
- max intensity at lt infraclavicular area

3- inv
Xray, ecg : normal
Eco : 3

4- ttt
Surgical Catheter
Prophylactic against infective endocarditis

Question 7

Talk about large pda ( his , exam)

Answer 7

1- history :
Onset : second week of life
- (6)
Dysnea , difficult suckling , recurrent chest inf , ftt, excersise intolerance , excessive sweating

2- exam
General :
1- ftt
2- recurrent chest inf
3- hf
4- HYPERDYNAMIC CIRC : big pulse volume ( water hammer sign )

Cardiac :
Insp, palp
1- lt v enlargement
2- systolic thrills in lt infraclavicular area ( very deep )

Ausc
1- auccentuted s2 ( pulmonary htn)
2- murmur :
- continous ( especially in systole due big pg )
- machinery
- max intensity on lt infraclavicular area or inside scapula ( بيسمع لورا

3- soft ejection ( mid ) systolic murmur ( pulmonary htn )

Question 8

Why big pulse volume

Answer 8

V= SBP - DBP
Systolic p is not affected as mich as diastolic as the lt ventricle will compensate the blood shunted by + its own p preserving the systolic p while diastolic p is decreased due to continous running off blood from aorta to pulmonary thus the gap will increase

120 - 40

Question 9

Complications - inv of large pda

Answer 9

Comp
1- hf
2- recurrent chest inf
3- infective endocarditis
4- ftt
5- pulmonary obst ~> eisenmenger syndrome but it causes differntial cyanosis as it is in the low half of body ( as pda is below the subclavian)

Inv
1- xray :
- lt v enlargement
- pulmonary dilation
- lung plethora

2- ecg : lt v enlargement
3- echo :
- size , position, blood flow
- pulmonary p ( prognosis)
- cardiac dilation, efficacy of contractility in lt ventricle

Question 10

Ttt

Answer 10

Medical
•Ttt of
- hf
- infective endocarditis
- recurrent chest inf

• Medical closure by
* indomethicin , ibuprofen, paracetamol
* in the fist two weeks only
* be aware of se of indomethcin ( nephritis ) thus
Following with kidney function test , bleeding profile

Surgical
Indications : failed medical ttt + over 6 kg infant
(Either small or large as it wont close as it is fibrotic , cant spasm )

Surgical or catheter

Banding of pa can occur in postponed cases

Question 11

Why is aorta named as second heart

Answer 11

As it dilates ( stretches ) in systole to work as shock absorber

And recoils in diastole pushinf blood forward