Flashcards in Pulmonary Vascular Disease - Pulmonary HTN Deck (27):
What's a simple definition of pulmonary hypertension?
High blood pressure within the pulmonary vascular bed.
Ohm's law solved for resistance?
Resistance = Pressure / Flow
Equation for Pulmonary Vascular Resistance (PVR)? (with cardiac catheterization values)
PVR = (mean PA pressure - mean PCW pressure) / CO
Does preload have a greater effect on the LV or on the RV stroke work?
The LV stroke work is more dependent on preload.
Does afterload have a greater negative effect on the LV or on the RV stroke volume?
The RV really can't deal with afterload - stroke volume rapidly drops off with increasing afterloads.
How are normal pulmonary arteries different from normal systemic arteries?
Systemic arteries deal with high pressures and are highly muscularized.
Pulmonary arteries deal with low pressures and are normally only minimally muscularized.
How do the arteries change in pulmonary arterial hypertension (PAH)?
Concentric intimal thickening / "plexogenic" changes.
(plexogenic means... vessels start to branch... not important)
Pulmonary hypertension is defined by a mean pulmonary pressure of what?
> 25 mmHg (ish)
3 pathophysiologic mechanisms of pulmonary HTN?
Increased flow. (chronic anemia, liver dis., L->R shunt... etc)
Elevation of outflow pressure. (left HF)
Increased PVR. (PAH, instrinsic lung dis., PE)
5 clinical classifications of pulmonary HTN (WHO groups)?
PAH (WHO Group 1).
Pulmonary HTN associated with L. heart dis. (2)
Pulmonary HTN with lung dis. and/or hypoxemia. (3)
Pulmonary HTN due to chronic thromboembolic dis. (4)
Miscellaneous and/or multifactorial. (5)
Progression of PAH, starting with increased PVR? (6 steps)
Increased RV afterload. (recall RV can't handle it)
Reduced RV ejection (CO) and pulm blood flow.
RV hypertrophy and/or dilation.
Why don't we normally have increased PA pressure with exertion? (when CO will normally be increased)
How does this vary in PAH?
Thought there is increased flow, our capillary beds have reserve volume to vasodilate and accomodate it.
If pt has PAH, PA pressure will increase markedly with exertion.
Normal pulmonary capillary wedge pressure (PCWP)? -estimate of LA pressure.
< 15 mmHg
Definition of increased PVR? (in Wood units)
> 3 Wood units
4 classifications of PAH?
Which are the 2 most common?
Idiopathic PAH (IPAH)
Heritable PAH (HPAH)
Drugs and toxins
Associated with _____ PAH (APAH)
IPAH and APAH are most common.
5 examples of diseases / pathophysiologies with which APAH is... associated?
Collagen vascular disease.
Congenital L->R shunt.
7 risk factors (from history) for PAH? - lots of overlap with the APAH causes,
Connective tissue disease.
Congenital heart disease (esp L->R shunt).
History of DVT/PE.
What drug might actually be responsible for a lot of "idiopathic" PAH?
(from a study at one center where 30% of IPAH pts had used meth)
Symptoms of PAH? (are they caused by the PAH itself?)
All related to inability to increase CO on demand.
Dyspnea, fatigue, pre-syncope, cough, chest discomfort, edema.
(these symptoms are often misinterpreted as being caused by something else)
5 physical exam findings associated with Pulmonary HTN?
Systolic murmur (tricuspid regurg.)
Diastolic murmur (pulmonary regurg.)
5 physical exam findings consistent with presence of RV failure?
JVD with V wave.
5 aspects of general medical management of PAH?
Diuretics (esp. spironolactone).
Digoxin (if RV failing).
Important lifestyle adjustments for PAH?
Avoiding stimulants and decongestants.
Low-salt diet, possibly fluid restriction.
Should pregnancy and PAH mix?
No. Never. Not even if she really wants a baby. Adoption's great.
(the mortality rate is 30%ish, which is unacceptable)
Prostacyclin -do you want it or not want it if you have PAH?
You want prostacyclin. PAH is associated with a prostacyclin deficiency (leading to increased cell proliferation, thrombosis, vasoconstriction, and inflammation)
Endothelin is important in causing PAH?
Endothelin causes vasoconstriction, but other things too.