Lec 19 Pulmonary Vascular Disease Flashcards Preview

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Flashcards in Lec 19 Pulmonary Vascular Disease Deck (61):
1

What is ohms version of equation of Pulm artery pressure?

KNOW THIS!!

Ppa = (CO * PVR) + Pla

Pla = left atrial pressure
b/c change in P = CO * R

2

What is ohm's version of equation of pulm artery pressure?

Psa = (CO*PVR) + Pra

Pra = right atrial pressure b/c changes in P = CO*R

3

How do pulm vessels differ from systemic vessels?

less muscle and elastin

4

What is definition of pulmonary hypertension?

mean Pa > 25

5

What are 3 mechs of what will cause increased pulm artery pressure?

- increased CO
- increase left atrial P
- increased PVR

6

What are some things that cause increased CO and thus lead to high pulm artery pressure?

- congenital heart defects w/ L to R shunt
- cirrhosis
- anemia
- A-V malformations

7

What are some things that cause increased left atrial P and thus lead to high pulm artery pressure?

- systolic/diastolic LV failure
- mitral valve disease
- restrictive cardiomyopathy

8

What are some things that cause incraesed PVR and thus lead to high pulm artery pressure?

- destruction pulm vascular bed in ILD, emphysema, PE
- hypoxic vasoconstriction in COPD, high altitude
- small pulm artery vasculopathy [PAH]

9

What is group 1 pulmonary hypertension?

pulmonary arterial hypertension

10

What is group 2 pulm HTN?

due to left heart disease

11

What is group 3 pulm HTN?

due to lung disease, hypoxia

12

What is group 4 pulm HTN?

due to thromboembolic disease

13

What is group 5 pulm HTN?

miscellaneous "other"

14

What are some pathological signs seen in pulmonary arterial hypertension?

- medial hypertrophy
- intimal thickening
- in situ thrombosis
- plexiform lesions

15

What is pathogenesis of pulmonary hypertension?

- increased endothelin pathway --> vasoconstriction and proliferation of smooth muscle

- decrease NO path --> less vasodilation/antiproliferation

- decrease prostacycline path --> less vasodilation and antiproliferation

16

What are 4 possible etiological categories of PAH?

- idiopathic
- genetic
- drug/toxin induced
- associated w/ other disease

17

What is genetic cause of pulmonary arterial hypertension?

- mutation in BMPR2

18

What drugs/toxins can cause pulmonary arterial htn?

- anorexigens [fen phen]
- grapeseed oil
- illicits

19

What are some diseases associated with PAH?

- connective tissue [SLE, scleroderma]
- congenital heart disease --> increased pulm pressure/flow
- portal htn
- HIV
- schistosomiasis

20

WHat is prevalence of PAH?

5-15 / 1 million adults

21

How prevalent is PAH in pts with CHD?

30% of pts who do not have CHD repaired will develop PAH

22

What is survival of untreated idiopathic PAH?

- median survial 2.8 years

34% survival at 5 years

23

What is difference RV and LV?

- LV concentric shape; thick free wall

- RV crescent shape; thin free wall; lacks circumferential constrictor fibers; more compliant

24

What is definition preload?

wall stress at end of diastole

25

What is definition afterload?

wall stress during ventricular ejection

26

What is contractility?

intrinsic ability of myocardium to contract independent of load

27

What happens to LV if dildate RV?

compress LV

28

Why do you get such rapid decompensation in PAH?

high pulm pressure means increased RV afterload

RV afterload --> increased RV wall stress --> ischemia and decreased output leading to decreased CO

RV afterload --> decreased RV output --> also decreases CO

RV afterload --> increase RV dilatation --> leftward septal shift and tricuspid regurg --> also decrease RV output and LV preload leading to more decreased CO

significant decrease LV ---> leading to cardiogenic shock

29

What are symptoms of PAH?

from low perfusion
- dyspnea
- fatigue
- chest pain
-palpitation

from congestion --> ab pain and fulness, peripheral edema

30

What do you seen on physical exam in PAH?

- hypoxemia, tachycardia, hypotension
- JVP distension
- RV head, split S2, loud P2, systolic tricuspid murmur
- RV S3/S4
- hepatomegaly, pulsatile liver, ascites
- lower extremity edema

31

Do you see rales in pure PAH?

nope! no pulmonary edema in pure PAH

32

WHat do you see on chest xray in PAH?

dilated pulmonary arteries
restro-sternal space disappears in lateral view

33

What do you see on EKG in PAH?

- RV hypertrophy/strain
- RBBB
- right atrial enlargement

34

What is use of right heart cath? What does it tell you?

- confirms diagnosis of pulmonary hypertension
- tells you hemodynamic profile --> RAP, PAP, PCWP, CI, PVR

35

What does PCWP tell you about etiology of pulmonary hypertension?

- if PCWP > 15 suggests PH type 2 [due to left heart disease]
- if PCWP < 15 consistent w/ pulm HTN that occurs before capillaries = type I [PAH]; III [lung disease; or IV [thromboembolic]

36

What is natural history of pulmonary hypertension?

in asymptomatic/compensated: CO still pretty high and RAP low; PAP/PVR rising

in symptomatic/decompensated: CO declining; PAP/PVR really high

in overt R HF: high PVR but PAP starts to decrease as CO drops and RAP increase = signs of low perfusion and congestion

37

What are the names of the 4 Ca channel blockers?

amlodipine/nifedipine
diltiazem/verapamil

38

What is use of Ca channel blockers in pulm htn?

- result in pulmonary arterial vasodilation
- beneficial if positive vasoreactivity test [vasoresponder]

39

What is test to see if patient is vasoresponder?

- give short-acting vasodilator like epoprostenol/adenosine/inhaled NO

- a vasoresponder will have decreased PAP by > 10 to absolute < 40 without concurrent drop in CO

only makes up 13% of population of pts with idiopathic PAH

40

What is mech of prostanoids?

- stimulate adenylate cyclase --> incrase cAMP
- cause vasodilation, antiproliferation, platelet aggregation inhibition

41

What is effect of prostanoids?

- improve hymodynamics; functional capacity

42

What is the one prostanoid that increases survival?

epoprostenol

43

What are the 3 types of prostanoids and their mech of administratiON?

epoprostenol = IV
treprostinil = SC, IV, PO, inhale
iloprost = inhaled

44

How is eoprostenol administered? half life?

1/2 life = 3-5 min
continuous IV admin

45

Which prostanoid is just synthetic prostacyclin?

epoprostenol

46

How is treprostinil administered?

IV and subcutanous = bioequivalent
1/2 life is 2-4 hrs

47

Where are the two types of endothelin receptor antagonists located? action?

- ETA/ETB on smooth muscle cells and cardiac myocytes
- ETB also on endothelial cells

both cause vasoconstriction/ proliferation smooth muscle

ETB also mediates pulmonary clearance and induces production of local mediators

48

What are the 3 endothelin receptor antagonists?

- bosentan
- ambrisentan
- macitentan

49

What is order of highest affinity for ETA/ETB among the 3 endothilin receptor antagonists?

ambrisentan > macitentan > bosentan

affinity ETA: ETB

50

WHat is effect of endothelin receptor antagonists?

improve hemodynamics and functional capacity

51

WHat is mech/effect of phosphodiesterase 5 inhibitors?

- inhibits cGMP specific phosphoidesterase

cause vasodilation/ antiproliferation/ platelet aggregation inhibition

improve hemodynamics and functional capacity

52

What are the 2 phosphodiesterase 5 inhibitors?

sildenafil [PO/IV]
tadalafil [PO

53

What is mech of action of riociguat?

stimulates solumble guanylate cyclase [sGC] --> converts GTP to cGMP

54

What is effect of riociguat?

vasodilation, antiproliferation, platelet aggregation inhibition

improves hemodynamics and functional capacity

55

What are some things you need to consider when you are giving vasodilators?

- vasodilation will decrease SVR not just PVR --> caution in hypotensive patients

- abrupt medication withdrawal causes rebound pulmonary HTN --> need to wean gradually

- can worsen V/Q match leading to hypoxemia --> caution in intrinsic lung disease

56

What are side effects common of pulmonary vasodilators?

vasodilation --> headache, dizziness, flushing, nasal congestion

57

What is a side effect of bosentan?

liver tox

58

What are side effects common to endothelin receptor antagonists?

- teratogenic, peripheral edema, anemia

59

What are side effects of prostanoids?

jaw pain

60

What are general treatment measures of pulm HTN?

- give supplemental O2 to maintain saturation > 90%
- anticoagulation
- digoxin to improve contractility
- cardiopulmonary rehab to improve functional capacity

61

What surgical treatments available for pulm HTN?

- atrial septostomy --> unloads RV at cost of hypoxemia
- pulm thromboendarectomy in case of chronic thromboembolic pulm htn
- lung transplant