Pulm Lec 24 - Vascular Disease

Front 1

how does the definition of HTN differ for PAH vs PVH?

Back 1

- PAH: PCPW <15mmHg

- PVH: PCPW >15mmHg

Front 2

is there a bigger difference between PA & PCWP for arterial or venous HTN?

Back 2

- bigger difference for arterial

Front 3

how do you increase PVR?

Back 3

- fibrosis, blood clot, destruction from COPD, polycythemia (increased viscosity), effective vessel radius (r) & length of vessel

Front 4

how much of the pulmonary bed do you have to destroy before you have a reduction in vessel radius & cause increased resistance?

Back 4

- 50-70% of vascular bed must be occluded

Front 5

what happens to vascular beds with chronic hypoxia?

Back 5

- endothelial disruption --> increased endothelium (vasoconstrictor) & decreased NO & prostacyclin (vasodilators)

- this leads to permanent remodeling

Front 6

what is cor pulmonale?

Back 6

- alterations in RV, may be acute (due to PE) or chronic (due to COPD)

Front 7

what does the PA pressure have to exceed to cause acute for pulmale & RV failure?

Back 7

- PA pressures >40mmHg

Front 8

what happens if we see PA pressures >40mmHg & no noticeable heart failure?

Back 8

- we know this is chronic pulm HTN

Front 9

what are the 5 groups of pulm HTN?

Back 9

- Group I: PAH (pulmonary arterial HTN)

- Group II: post capillary HTN (left sided heart disease, PCWP elevated)

- Group III: Pulm HTN from lung disease (COPD, ILD, chronic hypoxia – muscle weakness, OHS, shunts)

- Group IV: Chronic thromboembolic PH

- Group V: etiology not so clear

Front 10

how do you get group I PAH?

Back 10

- idiopathic, heritable

- connective tissue disease (scleroderma), VSD, ASD, portopulmonary HTN, HIV, drugs (weight loss)

Front 11

what type of pulm HTN does portopulmonary HTN cause?

Back 11

- PAH (Group I)

- because liver chirrosis won't allow you to normally produce vasodilators & clear vasoconstrictors

Front 12

what is group II pulm HTN?

Back 12

- pulmonary venous hypertension

- due to LV dysfunction, AS, AR, MS, MR

- Tx: ionotropic agents, diuretics, after load reducers

Front 13

what is group III pulm HTN?

Back 13

- related to parenchymal disease (COPD, ILD)

- Tx: treat underlying disease, give O2

Front 14

what is group IV plum HTN?

Back 14

- pulmonary embolic HTN

- Tx: thromboendarterectomy

Front 15

why do you get exertional symptoms w/ pulm HTN?

Back 15

- inability of RV to meet demands posed by exertion

- dizziness & syncope b/c systemic vasodilation during exercise, but not enough CO --> pass out

Front 16

what are PE signs of pulm HTN?

Back 16

- increased P2: pulmonic closure @ high pressures

- tricuspid regurgitation: ventricle diates & starts to fail so valve can't close properly (systolic murmur)

- RV heave b/c of hypertrophy, S3 abnormal filling from RV dilation

- distended neck veins, leg edema

Front 17

what is the gold standard to diagnose pulm HTN?

Back 17

- echocardiography

- estimates PA pressures, RV & LV function, valvular disease, shunt

Front 18

what is BNP?

Back 18

- brain natriuretic peptide --> neurohormone that is released by myocardium when it is doing too much work

Front 19

what could PFTs help us for with the diagnosis of pulm HTN?

Back 19

- figure out if it is group III

Front 20

what could blood work help us for with the diagnosis of pulm HTN?

Back 20

- CBC: see if hematocrit is high (increased viscosity)

- antibodies: rule out connective tissue diseases

- LFTs: tell us if there is liver failure

- HIV

Front 21

how do you confirm plum HTN?

Back 21

- right heart cath --> every patient gets this

- most accurate measure of PAP & PVR (then give pt IV vasodilator & see if resistance comes down, 90% of time they don't)

Front 22

what is idiopathic PAH?

Back 22

- F > M, peak incidence 20-60 years

- tremendous overgrowth of cells into the vessel, fibrotic tissue, blood clots & thrombi can form (in situ thrombosis)

Front 23

what is the gene most closely associated with pulm HTN?

Back 23

- bone morphogenic protein receptor (BMPR-II)

- theory is this gene leads to vascular proliferation of SM

Front 24

what is the pathophysiology of PAH?

Back 24

- endothelial cell injury --> VG K+ defect --> increased TBX/PGI2, decreased NO, increased endothelia --> vasoconstriction --> remodelling --> in situ thrombosis --> sustained pulm HTN

Front 25

what is endothelin? what types of receptors are there

Back 25

- A & B receptors --> A causes vasoconstriction & SM proliferation

- B causes BOTH NO, PGI2 (anti-proliferation) & proliferative effects

Front 26

if the pt responds to vasodilatory therapy (<10%) what could you use? ONLY FOR PAH

Back 26

- calcium channel blocker

- prostacyclins

- endothelin receptor antagonists

- PDE5 inhibitors

Front 27

how does prostacyclin work? NO? PDE5 inhibitor? endothlin?

Back 27

- prostacyclin: increases cAMP --> vasodilation & anti-proliferative effect

- NO: increase cGMP --> vasodilator, PDE5 is what breaks this down so inhibiting that would increase cGMP

- endothelin: want to block this b/c it causes vasoconstriction & vascular proliferation

Front 28

why could an atrial septostomy work for classes III or IV?

Back 28

- RA --> LA can help decrease the pressure

- could also do lung transplant

Front 29

what happens to V/Q during a PE?

Back 29

- initially V/Q increases (dead space), but then blood redistributes & start to get infarction, so that area of lung becomes atelectasis & begins to shunt

- V/Q mismatch causes hypoxemia

Front 30

what can PE do to hemodynamics?

Back 30

- releases serotonin (vasoconstrictor)

- massive PE can occlude 50-70% of circulation & lead to pulm HTN, acute cor pulmonale & shock (severe hypotension)

Front 31

how can you get infarction from a PE?

Back 31

- infarction happens with more distal clot b/c only have pulmonary circulation there - no bronchial circulation

- more proximal areas are protected by the bronchial circulation

Front 32

what is the pulmonary infarction syndrome?

Back 32

- pleuritic CP, dyspnea, fever (b/c release of cytokines), hemoptysis (doesn't have to happen)

Front 33

what is virchow's triad (HIS)?

Back 33

- risk factors for PE (>90% have one)

1) Hypercoagulability: malignancy, smoking, OCPs, factor problems

2) Inflammation: leg fracture, cellulitis, injury

3) stasis (immobilization): hospitalization, obesity, illness

Front 34

what does D-dimer tell you in a PE?

Back 34

- D-dimer increased in 95%

- therefore if it is positive doesn't mean much, if it is negative really decreases the probability

Front 35

what do blood gases tell you in a PE?

Back 35

- not much - they are NOT DIAGNOSTIC

- pt will be hypoxemic (but so is everyone else)

Front 36

what kind of angiograms would you do to visaulize PE?

Back 36

- CT angio most often done

- pulm arteriogram still the gold standard but rarely done

Front 37

what is the prophylactic treatment for PE?

Back 37

- low weight heparin

- compression stockings

Front 38

what is the treatment for PE?

Back 38

- initial: full dose heparin

- long term: warfarin

- thrombolysis if severe PE w/ hypotension & hypoxemia