Download Matters of the Heart

Matters of the Heart
Human Heart beats
100,000 time a day
Moving 6 quarts of
blood
through 60, 000 miles
Of vessels
(that’s 20 times the
Distance from coast to
Coast)
The heart itself holds
only 10 ounces of
blood, but pumps at
such a force that that a
severed artery can
propel blood several
feet into the air.
http://news.bbc.co.uk/2/shared/spl/hi/pop_ups/03/health_bodyphotos/html/1.stm
National Geographic
• http://www7.nationalgeographic.com/ngm/
0702/sights_n_sounds/index.html
• http://www.nationalgeographic.com/human
-heart/yourheart.html?fs=www7.nationalgeographic.c
om&fs=magma.nationalge
Broken Hearts
• Coronary Heart Disease is the #1 killer in
the USA
• 500, 000 people die from it each year in
the USA
• 7.2 million die worldwide
• More than 400,000 heart bypasses are
performed in the USA each year
http://www.daviddarling.info/images/heart.gi
f
Misconceptions about Heart Disease
• Most think cholesterol silts into arteries,
blocking them like a clogged pipe. Then
the artery gets completely blocked causing
a heart attack— no blood is getting
through to the heart.
• When actually, Plaque is a pimple-like
growth inside an artery wall with a “kind of
chronic pus”
Atherosclerosis animation
• http://www.nytimes.com/2007/04/08/health
/08hside.html?ex=1177732800&en=e0f0fb
9991a7734c&ei=5070
"Heart disease is not a one- or twogene problem,"
• says cardiac researchers Steven Ellis. Like most
researchers, he suspects that dozens of genes end up
contributing to a predisposition:
– Some affect arterial integrity,
– others inflammation (which both causes and exacerbates arterial
cracks),
– and still others the processing of lipids (the fats and cholesterol
that turn into plaques).
• Of the several dozen genes, each may contribute just
one percent to a person's total risk—an amount that may
be compounded, or offset, by outside factors like diet. As
one doctor told me, any person's heart attack risk is "50
percent genetic and 50 percent cheeseburger."
•
http://www7.nationalgeographic.com/ngm/0702/feature1/text2.html
Genes plus Other Risk Factors
• By tracking these genetic mutations, researchers hope to create a
comprehensive blood test that could calculate a person's
susceptibility to heart disease by adding up the number of risky
variables:
–
–
–
–
–
–
–
–
High unhealthy cholesterol levels (quadruples risk)
Smoking (double or triple risk)
Abdominal obesity (more than doubles risk)
High blood pressure/Hypertension (nearly triples risk in men, doubled it for
women)
Stress & Depression (almost triples risk)
Lack of exercise (increases risk by 20%)
Diabetes (quadruples risk for women, doubles it for men)
Healthy Diet (decreases risk by 30%)
• Assessing risk is crucial, Ellis says, because heart disease is often
invisible.
• In fact, 50 percent of men and 64 percent of women who die of heart
disease die suddenly, without experiencing any previous
symptoms.
Reducing Risk by Prevention
• Since detecting Heart Disease and predicting
whether a heart attack is imminent is so difficult,
prevention for everyone is advised.
• The only thing proven to reduce the risk of a
heart attack in someone with plaque is the same
thing that works to prevent plaque from
developing in the first place —
– Lowering blood pressure and blood sugar
– not smoking
– and Controlling cholesterol levels with
Statins
Statins: Lipitor
• Is a Drug that reduces the amount of LDL
(“bad” low-density lipoproteins) in the
blood made by the Liver
• Made by Pfizer, it’s best selling drug ever
made with $12 Billion in worldwide annual
sales
• Statins in general are the most prescribed
class of drugs in the world (11.6 million
monthly prescriptions in US alone)
Statins: How do they work?
• They work by blocking an enzyme in the liver that is involved in
producing cholesterol within liver cells.
"This tricks the liver cells into thinking the cholesterol levels are too
low within the cell and the cell puts more receptors onto its surface,
which drag the bad LDL cholesterol out of the blood," explains Dr.
Rory Collins, professor of epidemiology at Oxford University. "The
liver then breaks down that cholesterol and it's excreted into the bile
and into the gut."
Collins has conducted the biggest study of statins to date, covering
20,000 people over five years. The study suggested that a person
who has had high cholesterol for decades could reduce their risk of
heart attack or stroke by 25 per cent within just a few years of statin
treatment. The study also suggested that the risk would continue to
decrease, the longer the treatment continued.
http://www.cbc.ca/news/background/drugs/statins.html
Why do we make “bad” LDL in the
1st place?
• At one time, millennia ago, it may have been important for the
human body to be able to produce cholesterol – because early
humans may have gone long periods between meals, which meant
they couldn't count on getting enough cholesterol. But Dr. David
Jenkins – a Canada Research Chair in nutrition, and a professor of
medicine at the University of Toronto – says that's not the case for
the modern couch potato.
"We've got these ancient bodies with these ancient genes which are
all destined to make sure that we've got enough cholesterol to fulfil
essential functions," Jenkins told CBC Radio's Quirks and Quarks.
"Today, unfortunately, we've taken out all those nice things in the
diet that take cholesterol out of the body and have brought in a
whole load of very nice refined foods that allow us to sit around, not
do too much, and just synthesize cholesterol."
Those refined foods help your body produce the bad kind of
cholesterol.
• Angiogram of Healthy
Heart
• The picture of health, an
angiogram of a human
heart shows blood vessels
in sharp detail. To take an
angiogram, or arteriogram
x-ray, doctors must first
inject the patient with a
special opaque dye that
allows a clear view of the
heart's blood vessels,
including the large left and
right coronary arteries.
Narrowed arteries indicate
the presence of coronary
artery disease. Blockages
of either of the coronary
arteries could lead to a
heart attack. Such x-rays
help doctors determine a
course of treatment.
• Inside the Heart
• Tissue-paper thin but tough, the valves of the human heart open and
close to pump 6 quarts (0.9 liters) of blood a day through 60,000
miles (97,000 kilometers) of vessels. That's equivalent to 20 treks
across the United States from coast to coast. The heart is a
magnificent machine when it's in good working order. But coronary
heart disease is the number one killer of American men as well as
women, resulting in 500,000 deaths in the United States and killing
7.2 million people worldwide each year.
•
•
Donor Heart
At Houston's Ben Taub Hospital, careful—and quick—steps are taken to
prep a donor heart for transport and transplantation. To preserve the
harvested heart, a member of the transplant team flushes it with a cooling
solution that slows its metabolic rate. Doctors have a narrow window of only
four to six hours to get the heart into the waiting recipient before it is no
longer viable.
• Enlarged Heart
• Martti Tenhu, chief medical examiner in Helsinki, Finland, illustrates
the differences between a normal human heart and one enlarged by
alcoholism and high blood pressure. Covered in scar tissue, the
enlarged organ is nearly twice the normal size. Such alcoholic
cardiomyopathy weakens the heart so that it is unable to pump
blood adequately.
• Chest X-Ray
• Cause for concern is apparent in the chest x-ray of an 82-year-old
cardiac patient. Pneumonia in his right lung can be seen as clearly
as the pacemaker implanted to regulate the rhythm of his heart.
Pneumonia is a common hospital-acquired infection.
Controlling Risk Factors nearly
eliminates heart attacks altogether
• A 50-year-old man with:
– No diabetes
– Doesn’t smoke
– With normal cholesterol and blood pressure
• Has only a 5% chance of having a heart attack
or symptoms of heart disease, like chest pain,
over the next 45 years
• Same goes for a 50-year-old woman with those
risk factors under control. Her chance of
symptomatic heart disease is 8 percent, slightly
higher than the man’s because women live
longer
So Why does Heart Disease persist?
• Only 5 percent of 50-year-olds have those
risk factors under control.
• Even with just one major risk factor, such
as a high cholesterol level, and a man’s
chance of having symptomatic heart
disease rises to 50 percent.
• A woman’s chance rises to 39 percent.
Prevention gets little attention
• The fact is people like to eat
cheeseburgers, watch TV and go around
in cars
• It’s hard for a person to worry about a
disease that hits 10 or 20 years down the
road
•
http://www7.nationalgeographic.com/ngm/0702/feature1/text4.html
What are Blocked Artery Treatments?
Heart Transplant
Heart Transplant at 6 days old
http://www.jordanzane.com/
Artificial Heart
•
This polyurethane heart can keep critically ill cardiac patients alive while
they await a donated human heart. Once the device is surgically implanted,
its attached plastic tubes run through the patient's skin to a battery-powered
pneumatic pump. Despite the cost—$106,000—the demand is strong.
Some 3,000 people await heart transplants in the U.S., but only about 2,100
donor hearts are available each year. While boosting the supply of artificial
hearts is a relatively simple technical hurdle, increasing the supply of human
hearts is more challenging. Who will be tomorrow's donors? That question
lingers for a patient in Germany, who recently received a CardioWest
artificial heart like this one.
Stents
Widow-Maker
• An angiogram reveals
an abrupt closure in a
critical coronary artery.
• This technique uses a
catheter, dye, and xrays to navigate and
study blood vessels. In
a second angiogram,
bottom, after a stent
has been inserted,
blood flow is restored.
•
Figure 1
(a) Angiogram shows critical
stenosis in the intracranial right
internal carotid artery,
intrapetrous segment (arrow).
(b) Post-angioplasty angiogram
shows 40% residual carotid
stenosis (arrow). (c) Follow-up
angiogram shows recurrent
carotid 70% stenosis (arrow).
(d) Post-stent angiogram shows
excellent results with no
significant residual carotid
stenosis (arrow).