Flashcards in L68 Deck (29):
Describe typical pulm HTN pt
Young - 35 y.o.
2x more women
Long latent - 2 yrs of symptoms before dx
Is pulm HTN venous or arterial?
Arterial - duh!
B/c happening on the entry side into the lungs (but this is venous blood)
Think about it... makes sense
Define pulm HTN
- Mean pulm art pressure
- Pulm catheter wedge pressure = LVEDP
- Pulm vasc resistance
How do you get these values?
MPAP > 25 mm Hg
(12 - 18)
LVEDP 3 wood units
Low or high?
Resistance in pulm circulation
Compliance in pulm vascular bed
Impt b/c receiving the entire CO!!
What happens to pulm vasculature during exercise?
Increase flow + vaso dilation + recruitment
Net decrease pulm vasc resistance
What are the 4 changes to vasculature in PAH?
2. Endothelim and smooth muscle cell prolif
4. Plexiform lesions = tuft of cells where artery lumen should be
What are the end stage lesions in PAH?
What neurohormone is abnormally high in PAH?
- SM prolif
What neurohormones are abnormally low in PAH?
- Control cell prolif
- ↓platelet aggregation
How is NO made?
Arginine + NO synthase
How does prostacyclin vs NO vasodilate?
Prostacylcin = ↑cAMP
NO = ↑cGMP
What is bone morphogenetic protein receptor 2?
Genetic mutation associated with PAH
Mutated -> ↑apoptosis -> ↑cell prolif in vasc SM
PAH pt presentation
Chest pain / palpitations
Syncope - hemodynamic collapse
PE findings PAH
R heart strain:
- Loud P2
- Tricuspid regurg
- Pulm regurg
Fluid backup due to ineffective pumping:
- LE edema
3 CXR findings for PAH
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
EKG for PAH in early vs late disease (4)
Early = normal
1. R axis deviation
2. RA enlargement
3. RV hypertrophy
4. RV strain
PAH on echo
Size of the R and L heart switched
R = huge
L = small
What valve might show regurg on echo with PAH?
Due to high pressures, RV spits back into RA
What is the best way to screen for PAH? What do you need to do to definitively dx?
Best screening = ECHO
Dx need catheterization! (int jug vein)
What is the idea behind giving prostacyclin derivatives?
PAH pts are low in prostacyclin
So add an analog
- ↑cAMP -> vasodilation
Name 3 prostacyclin analogs
Epoprostenol - short
Treprostinil - longer
Iloprost - longer (inhaled)
Pros/cos to epoprostenol
Con = continuous IV infusion, if disconnect -> emergency
Pro = most effective therapy, survival benefit shown
Cons of treprostinil
Site rxn to subq infusions
- Can be given inhaled
What's the idea behind giving endothelin receptor antagonists?
Block the action of excess endothelin at receptor A + B
Some drugs are receptor specific vs others are non
2 endothelin receptor antagonists
Benefits and SE of Bosentan
Benefit = improve exercise capacity
- Monthly LFTs
- LE edema
Benefits and SE of Ambrisentan
Benefit = improve exercise capacity w/o need for LFTs
SE - worse LE edema
2 drug mechanisms to ↑cGMP
1. Exogenous NO - short half life, limited use outside hospital setting