if these lifestyle factors continue despite
The symptoms, I’ve mentioned before, we
call hypertension the silent killer because
for years there are no symptoms and when symptoms
develop, they are due to damage to various
We talked about hypertrophy – or – thickening
of the left ventricle and eventual heart failure
with shortness of breath, peripheral swelling,
fatigue. We talked about stroke and dementia,
or cognitive impairment in which patients
become forgetful, confused. Their personalities
change, they’re not the person they were
before this process began. Again, kidney damage.
Nephrosclerosis means scarring of the glomerulus
so that the glomerulus doesn’t work so the
kidney’s function is impaired and this can
lead to kidney failure and is a common cause
of patients needing dialysis. There can be
damage to the retina, which is the photographic
plate in the back of the eye, even with small
hemorrhages, and can lead to blindness. And
finally you can have blood-vessel damage anywhere
in the body with atherosclerosis and all the
complications that we’ve already been talking
about with atherosclerosis.
Therapy usually starts with medicines. When
we’re dealing with a hypertensive type where
surgery isn’t absolutely required – for
example coarctation – we would move early
on to surgery. But most patients with hypertension
are treated with medications. And we have
very effective medications these days for
controlling hypertension compared to when
Franklin Delano Roosevelt died of uncontrolled
hypertension because there were no drugs to
control his hypertension.
The first-line drugs that are most-commonly
used are thiazide diuretics and ACE inhibitors
and angiotensin blockers. We’re going to
go through all the classes in a moment. Calcium-channel
blockers are also first-line, particularly
for patients with kidney disease. Beta blockers
used to be first-line but have been moved
down now into second rank. And aldosterone
antagonists – remember, aldosterone is released
from the adrenal gland secondary to stimulation
from angiotensin. And there’s also drugs
that block the effect of aldosterone that
help lower blood pressure.
Let’s look at the drugs in a little more
First, let’s look at the thiazide diuretics.
Excellent first-line therapy alone or often
combined with angiotensin-converting enzyme
inhibitors, often called ACE inhibitors, or
angiotensin-receptor blockers, often called
ARBs. These are generic. They’re inexpensive
and they have been shown to reduce cardiovascular
events, such as stroke, in patients with hypertension.
The aldosterone antagonists are also very
effective. They bind at receptors in the kidney,
heart, blood vessels and the brain. They block
the effect of aldosterone on the kidney and
they increase sodium and chloride water excretion
and potassium excretion.
Beta blockers, as I’ve said, slow the heart
rate and they decrease cardiac output. They
also decrease renin release to a small degree
from the kidney. And these are second-line
agents for hypertension.
Calcium-channel blockers work by dilating
vascular smooth muscle and therefore they
decrease peripheral vascular resistance and
that decreases blood pressure.
The angiotensin-receptor blockers and the
angiotensin-converting enzyme inhibitors also
help block the release of the angiotensin
hormone system that causes vasoconstriction
and increased peripheral vascular resistance.
Finally just a word to tell you something
about how many anti-hypertensive agents are
needed for patients who have high blood pressure.
Here you see from a number of large, randomized,
double-blind controlled trials of hypertension
control versus placebo. And you can see most
of the trials require at least two – and
many of the trials require three drugs and
even some four drugs – to control blood
pressure. So usually one drug is not enough.
And often, of course, the drugs have to be
combined with lifestyle changes: weight loss,
control of diabetes and so forth. It’s not
just the drugs that do the job. There also
has to be exercise and weight loss and watching
the salt in the diet and so forth.