L68

Question 1

Describe typical pulm HTN pt

Answer 1

Young - 35 y.o.
2x more women
Long latent - 2 yrs of symptoms before dx

Question 2

Is pulm HTN venous or arterial?

Answer 2

Arterial - duh!
B/c happening on the entry side into the lungs (but this is venous blood)
Think about it… makes sense

Question 3

Define pulm HTN
- Mean pulm art pressure
- Pulm catheter wedge pressure = LVEDP
- Pulm vasc resistance 
How do you get these values?

Answer 3

MPAP > 25 mm Hg
(12 - 18)
LVEDP 3 wood units
(

Question 4

Low or high?
Resistance in pulm circulation
Compliance in pulm vascular bed

Answer 4

Low resistance
High compliance
Impt b/c receiving the entire CO!!

Question 5

What happens to pulm vasculature during exercise?

Answer 5

Increase flow + vaso dilation + recruitment

Net decrease pulm vasc resistance

Question 6

What are the 4 changes to vasculature in PAH?

Answer 6

1. Vasoconstriction
2. Endothelim and smooth muscle cell prolif
3. Thrombosis
4. Plexiform lesions = tuft of cells where artery lumen should be

Question 7

What are the end stage lesions in PAH?

Answer 7

Plexiform lesions

Question 8

What neurohormone is abnormally high in PAH?

Answer 8

Endothelin 1

• Vasoconstrict
• SM prolif
• Prothrombosis

Question 9

What neurohormones are abnormally low in PAH?

Answer 9

Prostacyclin
NO
Net:
- Vasodilation 
- Control cell prolif
- ↓platelet aggregation

Question 10

How is NO made?

Answer 10

Arginine + NO synthase

Question 11

How does prostacyclin vs NO vasodilate?

Answer 11

Prostacylcin = ↑cAMP
NO = ↑cGMP

Question 12

What is bone morphogenetic protein receptor 2?

Answer 12

Genetic mutation associated with PAH

Mutated -> ↑apoptosis -> ↑cell prolif in vasc SM

Question 13

PAH pt presentation

Answer 13

DOE
Dizziness
Chest pain / palpitations 
Leg edema
Syncope - hemodynamic collapse

Question 14

PE findings PAH

Answer 14

R heart strain:
- Loud P2
- Tricuspid regurg
- Pulm regurg
Fluid backup due to ineffective pumping:
- JVD
- Hepatomegaly 
- LE edema
- Ascites

Question 15

3 CXR findings for PAH

Answer 15

1. Peripheral lung vessels are hard to see b/c ↓BF
2. Large prox pulm arteries
3. (On side view) RV enlargement forward into retrosternal space

Question 16

EKG for PAH in early vs late disease (4)

Answer 16

Early = normal
Late
1. R axis deviation 
2. RA enlargement 
3. RV hypertrophy
4. RV strain

Question 17

PAH on echo

Answer 17

Size of the R and L heart switched
R = huge
L = small

Question 18

What valve might show regurg on echo with PAH?

Answer 18

Tricuspid

Due to high pressures, RV spits back into RA

Question 19

What is the best way to screen for PAH? What do you need to do to definitively dx?

Answer 19

Best screening = ECHO

Dx need catheterization! (int jug vein)

Question 20

What is the idea behind giving prostacyclin derivatives?

Answer 20

PAH pts are low in prostacyclin
So add an analog
- ↑cAMP -> vasodilation
- Anti-prolif

Question 21

Name 3 prostacyclin analogs

Answer 21

Epoprostenol - short
Treprostinil - longer
Iloprost - longer (inhaled)

Question 22

Pros/cos to epoprostenol

Answer 22

Con = continuous IV infusion, if disconnect -> emergency
Pro = most effective therapy, survival benefit shown

Question 23

Cons of treprostinil

Answer 23

Site rxn to subq infusions

- Can be given inhaled

Question 24

What’s the idea behind giving endothelin receptor antagonists?

Answer 24

Block the action of excess endothelin at receptor A + B

Some drugs are receptor specific vs others are non

Question 25

2 endothelin receptor antagonists

Answer 25

Bosentan

Ambrisentan

Question 26

Benefits and SE of Bosentan

Answer 26

Benefit = improve exercise capacity
SE:
- Monthly LFTs
- LE edema

Question 27

Benefits and SE of Ambrisentan

Answer 27

Benefit = improve exercise capacity w/o need for LFTs

SE - worse LE edema

Question 28

2 drug mechanisms to ↑cGMP

Answer 28

1. Exogenous NO - short half life, limited use outside hospital setting
2. PDE-I

Question 29

2 PDE-Is you need to know. Both are contra-indicated with what?

Answer 29

Sildenafil
Tadalafil
CI w/ nitrates: similar mechanism of action -> hypotension