Pulm #17: Pulm Hypertension And Cor Pulmonale

Front 1

The pulmonary circulation is a ____ [high, low] pressure, and ____ [high, low] flow system.

What is the pulmonary flow reserve?

Back 1

LOW pressure, and HIGH flow system.

Pulm flow reserve= unperfused areas of lung that can accommodate increases in CO if needed

Front 2

What is the cause for high capacitance of the pulmonary circulation?

Compared to systemic arteries, are pulmonary arteries more or less distensible?

Back 2

1) Recruitment of unperfused blood vessels
2) Distension and ↓ vasoconstriction (less smooth m.)

More distensible (due to less smooth m. and less vasoconstriction)

Front 3

What are some examples of Vasodilators? vasoconstrictors?

Which is dominant in the lung?

Back 3

Vasodilators- prostacyclin, NO, ANP, Sympathetic tone
Vasoconstrictors- Thromboxane A2, endothelin, hypoxia, serotonin, AgII

Vasodilators >> Vasoconstrictors

Front 4

What are the main determinants of Pulmonary Arterial Pressure?

What is the most important determinant of Pulmonary Venous Resistance?

Back 4

Pulm Arterial Pressure= [CO x PVR] + Pla
- CO
- pulm vascular resistance
- left atrial pressure

PVR= u=8ul/πr4
- arterial lumen area (most important)
- others: blood viscosity (hct, protein content)

Front 5

What are the three major mechanisms of Pulm HTN?

Back 5

1. Increase L Atrial pressure (i.e. pulm venous pressure)
2. Increase Pulmonary blood flow
3. Increase PVR

Front 6

What are the three causes of increased pulmonary vascular resistance (broad)

Back 6

1. Vasoconstrictive (ex: hypoxia induced)
2. Obstructive (ex: thromboembolism)
3. Obliterative (ex: emphysema, destroy capillary bed)

Front 7

What are the Five Groups of Pulmonary Hypertension?

Back 7

Group 1: Pulm arterial hypertension (PAH)
Group 2: Left Heart disease
Group 3: Lung disease or Hypoxemia (COPD,ILD, etc)
Group 4: Chronic thromboembolic HTN
Group 5: Pulm HTN with unclear mxn. (NOT DISCUSSED)

Front 8

Name some causes of PAH.

Back 8

- Idiopathic
- Hereditary
- Connective Tissue disease (scleroderma)
- Congenital heart disease (L-->R shunt)
- HIV, Schistosomiasis
- Persistent Pulmonary HTN of Newborn

Front 9

Which is the dominating factor in PAH: mitogens or anti-mitogens?

What layers of the vessel wall are involved in PAH?

Back 9

Mitogens >> Anti-mitogens

All three layers (int, med, adv.) involved.

Front 10

What is a plexiform lesion?

Back 10

Abnormal proliferation of pulmonary endothelial cells

Front 11

What is the pathogenesis of pulmonary hypertension?

Back 11

1. Genes (BMPR2) and Environment (drugs, inflammation, virus) cause -->
2. Vascular Remodeling (Cell/Matrix proliferation, Thrombosis) and Vasoconstriction -->
3. ↑ PVR

Front 12

What three things does "vascular remodeling" refer to?

Back 12

- cell proliferation (all parts of arterial wall)
- matrix proliferation
- thrombosis

all increase PVR

Front 13

What are the symptoms of PAH like?

Back 13

Non specific

- Dyspnea, fatigue, syncope (restricted CO)
- Chest pain (RV strain/ ischemia)
- Edema, JVD (RV failure)

Front 14

What might you find on the physical exam in a PAH patient?

How do you diagnose a person with PAH?

Back 14

- Loud P2
- RV heave (tricuspid murmur)
- Peripheral edema

Diagnose using R Heart Cath (measure PAP, CWP (essentially LV EDP), CO, and response to vasodilator).

Front 15

What should the following parameters look like in a patient with Pulm Artery HTN:

- PAP
- PVR
- CWP


In what demographic is idiopathic PAH seen?

Back 15

- Increased PA and PVR
- Normal wedge pressure (no heart failure)

- most common in young woman (frequently fatal)

Front 16

What is the gene for Familial PAH?

How does it's mutation result in PAH?

Back 16

BMPR2 (bone morphogenic protein receptor II)- part of TGF-β receptor family

- Mutated BMPR2 doesn't bind BMP. This messes up cascade and cell proliferation (endothelial & vascular smooth m. cells) i.e. vascular remodeling & HTN (PVR)

Front 17

What is the treatment for PAH?

Back 17

** Pulm Vasodilators **

- anticoagulation (warfarin)
- O2 for hypoxia
- Diuretics (RH failure, digoxin)

Front 18

How does Epoprostenol work?

How does Bosentan work?

Back 18

Epoprostenol- PGI2 - stimulates vascular smooth m to release cAMP --> vasodilation/ anti-proliferation

Bosentan- Endothelin Receptor antagonist (prevents vasoconstriction)

Front 19

What is the 6-minute walk test used for in PAH?

What are the four WHO classes of PAH?

Back 19

6 minute walk- tests exercise tolerance in patients with PAH

WHO classes:
I: dyspnea with strenuous exercise
II: slight dyspnea with normal activity
III: dyspnea with ADLs
IV: severe dyspnea, even at rest

Front 20

If someone had WHO class I and was vasodilator positive, what medication would be appropriate to treat PAH?

What is someone had WHO class II and was vasodilator negative? WHO class IV and vasodilator negative?

Back 20

WHO I, vasodilator positive --> CCB (ex: diltiazem)

WHO II, vasodilator negative --> Endothelin Receptor antagonist, Viagra

WHO IV, vasodilator negative --> PGI2 (epoprostenol)

Front 21

What class of Pulm HTN is due to Left Heart Disease?

What is the treatment?

Back 21

Class 2

- can be systolic or diastolic dysfunction
- Treat underlying disease!

Front 22

What class of Pulm HTN is due to high altitudes?

Why is Pulm HTN more common in "Blue bloaters"?

Back 22

Class 3 (Lung disease and/or Hypoxemia)

"Blue Bloaters" retain CO2 (have respiratory acidosis) and this enhances hypoxemia --> pulm HTN

Front 23

How does emphysema result in pulm HTN?

Back 23

Emphysema=
- destruction of blood vessels (obliterative cause of PVR)
- chronic hypoxia --> vascular remodeling
- alveolar hypoxia--> vasoconstriction

Front 24

What are the two most important causes of Pulm HTN in COPD?

Back 24

1. Alveolar hypoxia --> vasoconstriction
2. Chronic hypoxia --> vascular remodeling

Front 25

What class of Pulm HTN is due to clots?

How does a pulmonary thromboembolism cause Pulm HTN? What is the treatment?

Back 25

Class 4

- unresolved/ recurrent clots cause remodeling and obstruction of vessels
- Rx: anticoagulation, surgical removal of clot

Front 26

How does pulmonary HTN lead to Cor Pulmonale?

Back 26

Pathogenesis of Cor Pulmonale:

Pulm HTN --> Increased RV afterload --> RV hypertension --> RV dilation and failure

Front 27

What are classic physical exam features of Right sided heart failure?

What is the treatment?

Back 27

signs: JVD, peripheral edema, volume overload

Treatment= treat underlying heart/lung disease, oxygen, anticoag for embolism, lung transplant if unresponsive to vasodilators

Front 28

A patient comes in with non-specific symptoms of dyspnea, some fatigue, and syncope. How would you approach Pulmonary HTN?

Back 28

1. Document diagnosis with NON-INVASIVE testing (i.e. echo)
2. Establish if it's primary disease of lung or secondary PH (look at heart and lungs)
3. If PAH- do right heart cath and vasodilator responsiveness test
4. Evaluate RV function