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