WEBVTT - How Does Your Heart Get Blood?

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<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,

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<v Speaker 1>Lauren Vogelbaum. Here. Your heart works NonStop to deliver nutrient

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<v Speaker 1>rich blood to every part of your body, but its

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<v Speaker 1>first priority is always to take care of number one, A,

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<v Speaker 1>meaning itself. You can think of it sort of like this.

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<v Speaker 1>When you deposit money into a checking account, you establish

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<v Speaker 1>a system where all of your money passes from you

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<v Speaker 1>to your bank and then follows one of two paths.

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<v Speaker 1>It may either earn interest while the bank loans it out,

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<v Speaker 1>or it may scatter to pay for your various expenses,

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<v Speaker 1>but the bank most likely ear marks some small portion

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<v Speaker 1>of those funds for itself. First. When you look at

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<v Speaker 1>your monthly statement, you'll see all of the deductions you

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<v Speaker 1>made from your account, and there at the top a

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<v Speaker 1>monthly checking fee from the bank. Your heart handles blood

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<v Speaker 1>in pretty much the same way. In the average adult human,

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<v Speaker 1>the heart pumps about two thousand gallons of blood a

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<v Speaker 1>day through its chambers. That's about seven five hundred liters.

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<v Speaker 1>Of course, the average adult human does not hold that

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<v Speaker 1>much blood. The heart is pumping the same blood over

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<v Speaker 1>and over. Your heart beats about one hundred thousand times

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<v Speaker 1>every day to supply the cells in your body with

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<v Speaker 1>freshly oxygenated blood. That's a seriously powerful muscle, and it

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<v Speaker 1>means that even though your heart's function is to provide

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<v Speaker 1>other muscles with blood, it needs its own supply too. Today,

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<v Speaker 1>let's talk about how your heart gets that blood and

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<v Speaker 1>what can go wrong when it doesn't. Your heart receives

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<v Speaker 1>oxygenated blood in the same way that your brain, your feet,

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<v Speaker 1>and the rest of your body does through an artery,

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<v Speaker 1>but the heart takes the very first cut of the

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<v Speaker 1>good stuff arriving in from the lungs, just as the

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<v Speaker 1>bank makes sure its fees are paid first. To mix

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<v Speaker 1>our metaphors, the heart basically has its own freeway exit

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<v Speaker 1>for fresh blood that it's just pumping out. The oxygenated

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<v Speaker 1>blood coming out of the heart is getting on the

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<v Speaker 1>freeway to the rest of your body, and a little

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<v Speaker 1>bit gets off at the first overpass and takes a

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<v Speaker 1>side road back into the heart. But okay, let's back

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<v Speaker 1>up a little. Your heart is divided into four chambers,

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<v Speaker 1>the left atrium and left ventricle, and then the right

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<v Speaker 1>atrium and right ventricle. The left side is receiving fresh,

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<v Speaker 1>oxygen rich blood from your lungs, then sending it through

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<v Speaker 1>the left atrium down into the left ventricle, where the

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<v Speaker 1>heart's contractions forces it throw valve into the aorta at

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<v Speaker 1>one of the heart's main outward bound pipelines. The right atrium,

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<v Speaker 1>on the other hand, handles oxygen poor blood coming in

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<v Speaker 1>from all over the body and ships it down into

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<v Speaker 1>the right ventricle. From there, the heart's contractions force this

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<v Speaker 1>less than fresh blood out into the pulmonary artery, which

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<v Speaker 1>forwards it to the lung for reoxygenation. The heart can't

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<v Speaker 1>just take its oxygens straight from the blood that's constantly

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<v Speaker 1>passing through its chambers, partially because if that were the

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<v Speaker 1>way it worked, the cells on the right side of

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<v Speaker 1>the heart that intakes used blood from the body would

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<v Speaker 1>be out of luck, so the rest of the body

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<v Speaker 1>doesn't want the heart's cast offs. If the heart replenished

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<v Speaker 1>its own oxygen supply directly from the river of blood

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<v Speaker 1>flowing through it, the blood leaving the heart would have

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<v Speaker 1>less oxygen to deliver to the body. Instead, the muscle

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<v Speaker 1>exercises some restraint and feeds itself through arteries that run

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<v Speaker 1>off of the aorda, just like every other part of

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<v Speaker 1>the body. These arteries are called appropriately the left and

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<v Speaker 1>right coronary arteries. Once the aorta leaves the heart, blood

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<v Speaker 1>can branch off almost immediately into the coronary arteries. The

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<v Speaker 1>left coronary artery feeds the left side of the heart

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<v Speaker 1>and usually splits into two large branches, the left anterior

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<v Speaker 1>descending which descends down the front of the heart, and

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<v Speaker 1>the left circumflex, which winds back around the heart. The

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<v Speaker 1>right cornary artery supplies the right side of the heart

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<v Speaker 1>and the nodes that provide electrical signals to the heart.

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<v Speaker 1>Plus it branches off into the posterior descending artery, which

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<v Speaker 1>descends down the back of the heart. Interestingly, we don't

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<v Speaker 1>all have the same network of arteries feeding our hearts.

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<v Speaker 1>Some people have a third main coronary artery that juts

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<v Speaker 1>off of the aorta, and others have only a single

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<v Speaker 1>main coronary artery. Sometimes it's the right one instead of

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<v Speaker 1>the left, that branches into two more arteries. Regardless of

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<v Speaker 1>these harmless differences, the result is the same. The arteries

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<v Speaker 1>branch off in two smaller arteries, and all the arteries

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<v Speaker 1>and their branches wrap around the heart sort of like

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<v Speaker 1>a crown, hence the term coronary. This way, all of

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<v Speaker 1>the heart's tissues receive a fresh blood supply, giving it

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<v Speaker 1>the fuel it needs to pump day in and day out.

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<v Speaker 1>But what happens if something goes wrong? Problems and blockages

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<v Speaker 1>in the coronary arteries are what cause heart attacks. These

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<v Speaker 1>arteries start out big, soft, and smooth inside. They're usually

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<v Speaker 1>around three to four millimeters in diameter, which is a

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<v Speaker 1>little bit over a tenth of an inch, or around

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<v Speaker 1>the size of a cocktail straw. But as we grow older,

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<v Speaker 1>we can damage those once supple arteries via wear and tear, stress,

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<v Speaker 1>fatty and salty foods, and not getting enough exercise. Over

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<v Speaker 1>the decades, they collect plaque, which are fatty deposits along

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<v Speaker 1>their inner walls, causing the arteries to harden and narrow.

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<v Speaker 1>This condition is known as arthrosclerosis. Unchecked, it can develop

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<v Speaker 1>into coronary artery disease, also known as coronary heart disease.

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<v Speaker 1>As this condition advances, a number of things can happen.

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<v Speaker 1>For example, if a portion of your heart muscle is

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<v Speaker 1>receiving some but not enough oxygen due to partially blocked arteries,

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<v Speaker 1>your heart won't be happy about it. The muscle will

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<v Speaker 1>file a formal complaint with you in the form of

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<v Speaker 1>chest pain called angina. This can feel like pressure or

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<v Speaker 1>burning in your chest, like it's difficult to draw breath, or,

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<v Speaker 1>especially in women, like discomfort in the neck, jaw, or back,

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<v Speaker 1>maybe along with a stabbing chest or stomach pain. Angina

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<v Speaker 1>usually happens when you start exerting yourself, maybe if you're

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<v Speaker 1>climbing a flight of stairs or taking a brisk walk,

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<v Speaker 1>and will usually go away within a couple minutes once

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<v Speaker 1>you've had a chance to rest. You know, your heart

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<v Speaker 1>doesn't require much oxygen when you're sitting by the pool,

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<v Speaker 1>so it's usually fine, but the muscle will start feeling

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<v Speaker 1>the lack of oxygen when you start swimming laps. This

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<v Speaker 1>is called stable angina. It's something to pay attention to

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<v Speaker 1>and inform a healthcare provider about, but it's not an emergency.

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<v Speaker 1>Is an emergency is if you feel angina when you're

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<v Speaker 1>at rest, especially if it's severe and keeps going for

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<v Speaker 1>twenty minutes or longer. This is called unstable angina and

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<v Speaker 1>requires immediate medical attention because it means the heart isn't

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<v Speaker 1>getting enough blood to do its job period. Another thing

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<v Speaker 1>that can go wrong with the plaque build up inside

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<v Speaker 1>of your coronary arteries is sort of counterintuitive. You would

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<v Speaker 1>think that if one of these obstacles broke open, that

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<v Speaker 1>would be a good thing, but it can result in

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<v Speaker 1>a blood clot forming at the sight of the rupture

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<v Speaker 1>in the plaque. This little clot can totally block the artery.

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<v Speaker 1>Within minutes, heart tissue downstream of the artery will basically suffocate,

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<v Speaker 1>damaging the muscle. This is what's called a heart attack

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<v Speaker 1>or myocardial infarction. Similar symptoms apply a discomfort or pain

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<v Speaker 1>in the chest up through the jaw or down the

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<v Speaker 1>arm or back, shortness of breath, weakness or dizziness, and

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<v Speaker 1>sometimes a lot of nausea and sweating. And you probably

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<v Speaker 1>know this, but I'm going to say it anyway, this

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<v Speaker 1>is definitely a medical emergency, like to the point that

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<v Speaker 1>you should call medical professionals to send you help right away,

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<v Speaker 1>like dialing nine to one one instead of trying to

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<v Speaker 1>get yourself to a doctor. All of this can be

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<v Speaker 1>really scary, but there are lots of ways that healthcare

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<v Speaker 1>providers can help get a dangerously blocked coronary artery up

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<v Speaker 1>and running again. For example, Balloon angioplasty. This procedure uses

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<v Speaker 1>a tiny medical grade balloon to open a clogged artery

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<v Speaker 1>near the groin or in the arm. The provider accesses

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<v Speaker 1>a blood vessel that leads to an artery that leads

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<v Speaker 1>to the heart. They'll insert one or more wires and

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<v Speaker 1>catheters and thread them up through the artery using special

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<v Speaker 1>dye and an X ray machine. They'll find any blockages.

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<v Speaker 1>Once found, they lead the catheter to the blockage and

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<v Speaker 1>briefly inflate a tiny balloon on the tip to push

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<v Speaker 1>the plaque aside and allow blood to flow more freely.

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<v Speaker 1>This won't stop the arteries from blocking again, but it

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<v Speaker 1>will help prevent an emergency and ease any discomfort that

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<v Speaker 1>you're experiencing. Sometimes, in addition to or instead of an antioplasty,

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<v Speaker 1>a metal or plastic tube called a stent may be

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<v Speaker 1>inserted into a blocked artery to help prop it open.

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<v Speaker 1>Doctors may perform angioplasty and stenting on a patient before, after,

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<v Speaker 1>or during a heart attack. Some cardiologists prefer just stenting

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<v Speaker 1>without angioplasty. The drawback of this procedure is that stents

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<v Speaker 1>can clog just like your arteries. The upside to these

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<v Speaker 1>procedures is that they're relatively non invasive. The patient can

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<v Speaker 1>be awake, though mildly sedated. If things are a little

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<v Speaker 1>more serious, a provider may perform what's called a coronary

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<v Speaker 1>artery bypass graft. During this procedure, the provider temporarily stops

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<v Speaker 1>the heart and sets up artificial respiration. A vainer artery

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<v Speaker 1>that won't be missed too much is taken from somewhere

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<v Speaker 1>else in the body, possibly your arm or leg. Surgeons

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<v Speaker 1>attach one end of the graft to the a orda

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<v Speaker 1>and the other end to the artery on the far

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<v Speaker 1>side of the blockage. This detour enables blood to bypass

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<v Speaker 1>the blockage and flow unobstructed. When you hear the terms double, triple,

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<v Speaker 1>or even quadruple bypass surgery, it refers to the number

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<v Speaker 1>of arteries receiving bypass graphs. Of course, these procedures are

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<v Speaker 1>only part of a treatment plan for making sure that

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<v Speaker 1>your hard working heart gets the blood supply that it needs.

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<v Speaker 1>A health care provider may prescribe medications or recommend basically

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<v Speaker 1>cardiac physical therapy in the form of exercise or changes

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<v Speaker 1>to your diet or mental health care to help with

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<v Speaker 1>anxiety and stress. As always, if you're concerned about yourself

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<v Speaker 1>or a loved one, talking to a medical professional should

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<v Speaker 1>be the first step. There's a lot of information and

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<v Speaker 1>mis information out there about what's healthy, and they'll be

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<v Speaker 1>able to help you personally, cut through the noise and

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<v Speaker 1>keep that blood flowing. Today's episode is based on the

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<v Speaker 1>article how and why does the heart pump blood to

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<v Speaker 1>itself on how stuffworks dot com, written by Tom Sheeve.

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<v Speaker 1>Brain Stuff is production of iHeartRadio in partnership with HowStuffWorks

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<v Speaker 1>dot Com, and it is produced by Tyler Klang. Four

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<v Speaker 1>more podcasts from my heart Radio. Visit the iHeartRadio app,

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<v Speaker 1>Apple Podcasts, or wherever you listen to your favorite shows.