00:00
Pulmonary hypertension. So the other common pulmonary
circulation problem as well as PEs is pulmonary hypertension.
00:07
And what this means is a raised pulmonary artery pressure,
above 25 mmHg at rest, above 30 mmHg during exercise.
00:16
Now this is incredibly common as a complication of hypoxic lung disease,
which case is called cor pulmonale or left-sided heart disease.
00:26
And those circumstances are not
often treated as a specific issue.
00:30
There are also a range of causes of pulmonary hypertension
independent of lung disease and left-sided heart cardiac disease.
00:39
And we'll discuss those in
a bit more detail later.
00:43
With pulmonary hypertension, the course of the pulmonary
hypertension in cor pulmonale is the hypoxia itself.
00:52
So the standard reaction of a pulmonary
artery to hypoxia is vasoconstriction.
00:57
That's to ensure ventilation
perfusion matching occurs.
01:01
But in somebody who is very severely affected
by lung disease with widespread hypoxia,
that physiological response only occurs of pulmonary circulation
vasoconstriction in response to hypoxia becomes a pathological problem.
01:17
As the vasoconstriction increases depression of pulmonary
artery circulation and eventually leads to right-sided failure.
01:23
And that's called cor pulmonale.
01:26
In addition, patients with left-sided cardiac problems
that will raise the pressure in the pulmonary veins
and then that will raise the pressure of pulmonary capillaries and then the pulmonary
arteries as a sort of back pressure issue from the left-sided cardiac disease
and that occurs with left-sided cardiac
myopathies, cardiac failure and valvular disease.
01:48
Emphysema, specifically, causes lung
destruction and as it destroys the lung
that will also destroy aspects of the pulmonary
circulation leading to pulmonary hypertension.
01:59
And then the pulmonary arteries can be blocked
independent of any issue the lungs or cardiac problems.
02:06
And this most commonly occurs in what I described
earlier, which is multiple small pulmonary emboli.
02:14
But in addition, there are a bunch of diseases where you
get endothelial abnormalities of the pulmonary circulation
leading to pulmonary artery hypertension due
to loss of the pulmonary artery circulation.
02:26
And that leaves us with primary
pulmonary hypertensive diseases.
02:31
So we're going to list the course
of pulmonary hypertension.
02:35
These top categories are the rare causes and these are the ones I've just
described where you get primary problems of the pulmonary artery circulation.
02:45
And that's divided idiopathic which turns to be
young ladies, the reason for that is not clear.
02:51
Can be due to toxins. ___ phentermine, grape seed oil
have all been associated with pulmonary hypertension.
02:58
It is frequently associated to kinds of tissue disorder
such as systemic sclerosis, chronic HIV infection
that has a late complication of pulmonary hypertension, and
sarcoidosis occasionally also causes pulmonary hypertension.
03:11
That category is the rare causes. Now the second degree causes
are the common causes is the chronic hypoxic lung disease
causing cor pulmonale and the most
common cause of that will be COPD.
03:25
Congestive cardiac failure, mitral valve disease as we already
mentioned, but there are other causes of chronic hypoxic lung disease
that may end up causing secondary pulmonary hypertension such as obesity,
hyperventilation, chest wall restrictive disease, interstitial lung disease.
03:40
And then there is direct occlusion of pulmonary artery
circulation which is the most common cause of that
will be chronic thromboembolic disease with multiple small PEs knocking off
individual small arterioles which over time leads to pulmonary hypertension.
03:56
A similar situation can occur in sickle
cell disease and in patients affected
with just the ____ although if both of those are
___ could lead to chronic thromboembolic disease.