Pulmonary Hypertension

Question 1

Key features of pulmonary circulation

Answer 1

High flow, low resistance, high capacitance

Question 2

Pulmonary VR is what fraction of SVR

Answer 2

1/15 due to large cross-sectional area

Question 3

What are some causes of pulmonary hypertension

Answer 3

LV dysfuction, left atrial disease, valvular disease
COPD
Chronic thromboembolic disease

Question 4

What is Pulmonary arterial hypertension

Answer 4

It’s exactly what it sounds like and is not accounted for by any of the previous causes

Question 5

Primary pulmonary arterial hypertension

Answer 5

Is idiopathic in nature

Question 6

Some broad categories of things that cause PAH

Answer 6

Heritable, drug and toxin induced, associated with HIV/schisto/connective tissue disease

Question 7

General definition of pulmonary hypertension

Answer 7

Resting mean pulmonary artery pressure >25

Question 8

Definition of pulmonary arterial hypertension

Answer 8

Resting mean pulmonary artery pressure > 25, Left sided pressures 3 wood units

Question 9

Some vascular changes associated with PAH

Answer 9

Vasoconstriction. Smooth muscle and endothelial cell proliferation. Thrombosis

Question 10

Vascular remodeling associated with PAH

Answer 10

High flow low resistance system becomes low flow high resistance due to smooth muscle hypertrophy, in situ thromboses, intimal proliferation. Plexiform lesions

Question 11

Pathology of pulmonary hypertension reveals

Answer 11

Medial thickening and compressed lumen. Intimal fibrosis, , and plexiform lesion formation

Question 12

Mechanisms of PAH

Answer 12

Homeostatic imbalance of vascular effectors that favor vasocontriction, thrombosis and mitogenesis (growth).

Environmental and genetic factors too.

Question 13

Prostacyclin

Answer 13

A vasodilator, inhibitor of platelet activation and is antiproliferative. Reduced in PAH in comparison to TXA2

Question 14

Thromboxane A2

Answer 14

Released by platelets, vasoconstrictor. Levels are increased in PAH.

Question 15

Serotonin in PAH

Answer 15

Acts as a vasoconstrictor, promotes smooth muscle cell hypertrophy. Elevated plasma levels in PAH patients

Question 16

Endothelin 1

Answer 16

Potent vasoconstrictor that promotes smooth muscle cell proliferation. Levels increased in PAH. Levels are inversely proportional to magnitude of pulmonary blood flow.

Question 17

NO

Answer 17

Vasodilator and inhibitor of platelet activation and smooth muscle cell proliferation. Endothelial NOsynthase is decreased in PAH

Question 18

Hypoxia effect on systemic circulation and on pulmonary circulation

Answer 18

In systemic, hypoxia induces vasodilation.

In pulmonary, hypoxia induces vasoconstriction.

Question 19

How does hypoxia contribute to PAH

Answer 19

Can lead to PA vascular remodeling

Question 20

What drugs are associated w/PAH?

Answer 20

Fen-phen. Cocaine/methamphetamines (associated with medial hypertrophy of pulmonary arteries)

Question 21

What genetic defects are associated with PAH

Answer 21

Mutations in the TGFß receptor pathway. Bone Morphogenic protein receptor (BMPR2) type 2 has been shown to modulate the growth of vascular cells. Incomplete penetrance though.

Also in serotonergic pathway. Depending on receptorq

Question 22

Hemodynamic progression of PAH during presymptomatic/compensated period

Answer 22

Cardiac output still normal. Pulmonary artery pressure increasing, PVR increasing, right atrial pressure still low.

Question 23

Progression during symptomatic/decompensating period

Answer 23

CO dropping due to increased PAP and PVR. RAP increasing because it can’t handle increased volume backing up from PA

Question 24

Progresion during the declining/decompensated period

Answer 24

CO drops dramatically and causes right heart failure.

PVR increases still. RAP increases dramatically. PAP actually drops because RV can’t pump into pulmonary artery.

Question 25

What is an ominous sign that PAH has gotten really bad

Answer 25

If pulmonary artery pressure drops during severe disease. This signals that the right heart cannot pump into the severely stenotic pulmonary arteries.

Question 26

prognosis of PAH

Answer 26

Not good, 3 year survival is 58%

Question 27

Symptoms of PAH

Answer 27

Dyspnea, Fatigue, Chest pain, near syncope, edema,

Question 28

Signs of PAH

Answer 28

Elevated JVD, Tricuspid regurg due to increased PA pressures, grahm-steel murmur, Accentuated p2, S3 gallop on the right side, peripheral edema, hepatomegaly

Question 29

EKG findings

Answer 29

Not sensitive enough to be a screening tool. However, frequently RVH – > big R wave in anterior prevordials (V1 v2 v3)

Question 30

Roentgenogram findings for PAH

Answer 30

Enlargement of central pulmonary arteries, reduced caliber of peripheral vessels. Cardiomegaly w/ RV enlargement, enlargement of R and L PAs.

Question 31

Best diagnostic test for PAH?

Answer 31

TTE

Question 32

How to do the workup for PAh

Answer 32

Make sure that PAH isn’t just pulmonary hypertension. Look for chronic lung disease, look for infection, look for thrombi.

Question 33

What should patients avoid doing with PAH?

Answer 33

Keep SaO2 high. Avoid vasoconstrictors, avoid valsalva, avoid pregnancy.

Question 34

Treatment for PAH

Answer 34

PDE5 inhibitors, Prostacyclin derivatives to increase cAMP. Endothelin receptor antagonists.