シャドーイング練習: Left Sided Heart Failure - 動画で英語スピーキングを学ぶ

Hi everyone, Dr. Mike here.

In this video, we're taking a look at left side heart failure.

Let's jump straight into it.

Alright, to begin, let's orientate ourselves.

I've separated the left and right hand side of the heart up here

so it makes more functional sense because each side has their own circulation.

So because we're focusing on the left hand side, let's look at this.

The left hand side of the heart, which I've got is the left atrium here and the left ventricle here, it receives blood from the lungs.

So here I've got an alveolus, which is a representation of the lungs.

And here's the post capillary aspect of the pulmonary circulation.

So it receives oxygenated blood from the lungs going into the left atrium through the mitral

or bicuspid valve into the left ventricle.

It contracts with all that muscle.

Remember left hand side of the heart is three to four times thicker than the right hand side

because it has to pump blood to the entire body.

So it contracts forcefully, pushes blood out through what's called the aortic semilunar valve into the aorta

and then sends this blood out through the systemic circulation to all the tissues of the body.

So that is the circulation of the left hand side of the heart, receives blood from the lungs, sends blood to the body

so this is really important to understand heart failure behind the

left -hand side of the heart is the pulmonary circulation in

front of the left -hand side of the heart is the systemic circulation

because when we have heart failure

so let's define it an inability of the heart to effectively

work as a pump its job here to effectively work as a pump is to ensure

that there's no congestion behind so it receives the blood it needs and that the blood that enters

leaves appropriately to meet the metabolic demands of the body that's how it needs to work as a pump

if any of those things don't happen so congestion occurs behind or inadequate outflow in front

that's heart failure now let's look at left side heart failure

and some of the causes so that it makes sense anything

that can affect that is going to cause left side heart failure

so let's focus on our first one first one that we want to focus on here is arterial hypertension arterial

hypertension so hypertension is high blood pressure

but it's referring to chronic right you know high blood pressure over time

so effectively you don't just have one vessel here obviously you've got all of these multitude of arteries

and arterioles and if you've got a degree of occlusion

or blockage so let's say there's something that's narrowing this vessel like an atherosclerotic plaque for example

and this atherosclerotic plaque you know it can start forming clots

and then clots can narrow the hollow lumen of the vessel right

but what happens is if that's narrowed or the blood vessels are constricting

when they shouldn't blood tends to back up now this is

arterial hypertension right the left hand side of the heart it's going to receive blood normally,

it's going to fill normally and then the myocardium of the left ventricular wall will contract to eject that blood out.

But look it's facing resistance, now it's facing a pressure resistance so there's pressure to overcome.

Now in order to overcome this pressure, because think if it contracted as normal it would hit this pressure

and some blood would fall back in so not enough blood would leave, that would be heart failure.

We don't want that.

So the left myocardium, the left ventricular myocardium remodels itself in response to this pressure overload.

This is actually called afterload, increased afterload.

So this is really important, particularly when it comes to understanding heart failure,

is that if you have increased pressure or pressure overload that you need to overcome in the heart.

The heart will compensate by changing structurally.

So what the heart does is it undergoes what's called concentric hypertrophy.

So hypertrophy is when the heart gets, or the tissue gets larger.

Here we're talking about cardiac tissue, so the myocardium, it gets larger.

So we need to add some contractile subunits, sarcomeres, to get larger.

So the concentric is telling you in what way it's getting larger

so again if it's in response to having to overcome a pressure

or pressure overload it gets bigger through concentric hypertrophy

which means this the heart will let's say the hollow inside of the heart looks like this,

and there's the myocardium, its response is it will get bigger like this.

Because what it's done is if that is a sarcomere and that's a sarcomere and that's a sarcomere,

it will add sarcomeres in parallel, making it thicker.

So what you get is a thicker heart muscle but what

that means is the hollow inside of the heart reduces and

so you go okay in the early stages of responding to

this pressure overload this concentric hypertrophy works in some degree

because just like going to the gym you're experiencing a resistance the muscle needs to get bigger

and stronger to overcome that resistance right so you get concentric hypertrophy

but over time it's consistently having to overcome this increased pressure

and it starts to encroach on the hollow inside of the ventricle which means that less blood is entering.

So what we get is decreased filling.

Less blood is entering but because I've also got

so much muscle here it's hard for it to relax and it remains stiff.

So you get decreased filling and increased stiffness and these things together result in decreased output and what we get?

Left -sided heart failure.

So that is due to arterial hypertension.

Now there's another cause, there's a couple more for left -sided heart failure.

Another cause here is what we call ischemic heart disease.

Ischemic heart disease.

Sometimes it's referred to as coronary artery disease.

So what we're saying here is, instead of the narrowing happening here in the systemic vessels,

the systemic arteries, the narrowing happens to the blood vessels that are feeding the heart muscle itself, the coronary supply.

So here's a coronary artery here and the blood will enter

and diffuse across to feed this nice thick myocardium but

if it is blocked due to an atherosclerotic plaque

and then maybe a clot forms and travels through and blocks it

so let's say we've blocked a fair chunk of this

that muscle doesn't get fed

and the muscle dies you've probably heard this before it's called a heart attack right a myocardial infarction So an MI,

a myocardial infarct, right?

An MI.

And so that means the heart muscle begins to die off.

And if that heart muscle begins to die off, it can no longer contract, right?

And if it doesn't contract, it can't eject enough blood.

It doesn't work appropriately as a pump.

It's not meeting the metabolic demands of the body, left side heart failure.

But in addition, what can happen is that over time, the heart tries to remodel and compensate.

Now, we spoke about a form of remodeling in response to overcoming pressure, but is there a pressure here to overcome?

No, there's not, right?

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Because this isn't here.

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We don't have this arterial hypertension.

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All we have is the muscles dying off.

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So what do we do?

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How can we overcome this?

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Think about it.

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If that's dying off and it can't contract properly, right?

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The filling is fine the pressure here is fine, but because it can't contract hard enough, it doesn't eject enough.

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So the filling is normal, but the ejection is low.

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So you get a volume overload issue.

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Remember here, it was a pressure overload issue.

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Now you've got a volume overload issue.

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And the heart remodels in a different way in response to volume overload.

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So in response to volume overload, we get eccentric hypertrophy.

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Eccentric hypertrophy.

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So remember I said here we're adding sarcomeres in series.

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Oh, sorry, in parallel.

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I've given it away.

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We add sarcomeres, however you spell parallel.

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I can tell you all about biology.

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I can't spell.

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We're adding it in series in this instance.

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So again, the heart starts like this, the left ventricle starts like this as a normal size, but then it goes like this.

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It gets bigger because it's hypertrophy, but you get a dilated hypertrophy,

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what we call a dilated cardiomyopathy.

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Because what we've done is it's gotten bigger, but it's added sarcomeres.

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So there's the sarcomeres that existed.

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We've added them in series next to them to make it bigger but not thicker

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right so you get this dilated effect

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so this is what can happen over time in response to volume very important

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and so that what ends up happening is it just keeps filling with blood

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and it can't contract adequately to meet the requirements for output all right

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so that's the second i didn't even finish writing ischemic that's how bad i am at spelling all right

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so another one we've got arterial hypertension we've got ischemic heart disease

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and we need to talk about the next one which is valvular disease.

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All right.

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So what were the valves I spoke about in the left -hand side of the heart, right?

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We've got this valve here, which is called the mitral valve, also known as the bicuspid valve.

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And this valve here, which is called the aortic valve, sometimes called the aortic semilunar valve.

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All right.

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here's what can happen in this instance let's start with aortic valve if you have an aortic

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valve stenosis or a stenotic

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so stenosis means stiffening hardening uh stiffened aortic valve it's not going to open

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and close properly right so it stays stiffly shut

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so it's hard for the blood to get ejected now think about

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that if it's hard for the blood to get ejected And what was a scenario we spoke about where that happened?

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Arterial hypertension, remember?

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In arterial hypertension, it was trying to overcome the systemic blood pressure that was going back,

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but it's no different really to having to overcome a stiffened valve.

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So the same thing happens as here, is that because you're trying to overcome that,

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it's a pressure overload issue and the heart remodels to get thicker.

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So it gets thicker but again this thickness gets so thick

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that it narrows the inside of the ventricle

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and it can't maintain itself over time and so you can then get left side heart failure.

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So that happens as well in the aortic valve stenosis very similar to what's happening here.

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You can have not a mitral valve stenosis but what's called mitral regurgitation

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so that means it's sort of the opposite of the stiffness it's a bit floppy right

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so if it's a floppy valve it's not going to close properly it might sort of flat back

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and that means

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when this ventricle contracts not all the blood gets ejected some jumps back up into the left atrium

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which then means think about this which then That means when it relaxes, that blood falls back down and overfills the heart because you got the normal blood entering,

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not the normal blood leaving.

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Some goes up here, so it's adding to the next filling event.

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What's that?

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It's a volume overload issue.

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So what happens in martial valve regurgitation is you get an eccentric hypertrophy and a dilation of that ventricle.

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See, it's all making sense now, I hope.

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There's another set of causes here, and this is what we call dilated cardiomyopathies.

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Dilated cardiomyopathies.

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So cardio heart myopathies are muscle pathologies, muscle changes, and it's dilated.

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So it's this that's happening.

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But it's due to non -overload issues or non -overload causes.

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What do I mean by that?

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Well, these are the overload causes, right?

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So the fourth set of causes, the dilated cardiomyopathies, that happens,

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but it's not in response to increase pressures that it needs to overcome

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and it's not in response to increased volume effects that it needs to overcome.

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It's due to other strange things that are happening in the body and they all have their own specific mechanisms.

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So what can cause this?

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Well, it can be alcohol abuse.

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It can be cocaine.

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It can be some chemotherapies.

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It can do it.

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Genetics.

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right, so it can be inherited, diabetes, mellitus, obesity, right, so all age,

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so all these things in their own way can actually result in this dilated cardiomyopathy,

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but it's not in response to overcoming pressure changes or increased volume, all right.

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So these are the major causes for left side heart failure.

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Let's talk a bit about the symptoms, all right, So how does it present should be pretty easy because we know what's happening

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backwards and forwards and what you can have is backwards the symptoms due to backwards failure

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so due to congestion and symptoms due to forward failure

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so reduced cardiac output i think that's probably worth writing down what do you think

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so let's say you can have backward failure backward failure and that's due to congestion

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and you can have forward failure and that's due to reduced cardiac output so reduced amount of blood leaving the heart.

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So let's think about this first let's start with backwards failure

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if you've got blood not ejecting

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and it backs up backs up backs up into the pulmonary circulation here think about

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that this is coming from the lungs this blood backs up into the pulmonary And you get pulmonary congestion.

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So what you can get for backwards failure is pulmonary congestion,

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which means the blood is just backing up into the pulmonary circulation.

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But then it gets into the capillary bed and fluid will leak out into the alveoli.

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right and that fluid accumulation is pulmonary edema now if you've got pulmonary edema

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what do you think that means can you exchange gases well no

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because there's a thickened respiratory membrane here so it's harder for oxygen

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and carbon dioxide to get transported mainly the oxygen

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because carbon dioxide diffuses relatively well in fluid better without it but relatively well.

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So what are you going to get as your symptoms here?

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It's going to be dyspnea, right?

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So that's a shortness of breath or an alteration in breathing and orthopnea.

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So this means when you lay down you get this shortness of breath

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and that's because of the way that the fluid sits in the lungs reducing its ability for gas transport to occur.

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So that's the backwards failure effects of left side heart failure.

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What are the forward failure effects?

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So let's have a look at the forward failure effects.

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Well, because you've got a reduction in blood flow going forward, right?

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You've got a reduction in cardiac output.

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You end up getting less oxygen and nutrients to the tissues, including muscle.

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So what you end up getting is what?

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Fatigue, right?

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Exhaustion, weakness.

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So fatigue, weakness.

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And it might be exercise or even non -exercise induced depending on the degree, right?

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Exercise or non -exercise induced.

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Again, can't spell induced.

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So that is a set of symptoms that can happen due to the forward failure.

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So left side heart failure, the respiratory issues, pulmonary congestion, pulmonary edema, shortness of breath, orthopnea.

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When it comes to the reduced ability to give oxygen and nutrients to the body, fatigue and weakness because you're not getting the oxygen and nutrients you need, particularly to the muscle.

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So you might exercise and be even more exhausted and weak, fatigued and so forth.

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So look, this is Left Side Heart Failure.

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I'm Dr. Mike and I hope that helps.

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Thank you.

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このレッスンの語彙とスピーキングのポイント

このスピーキングレッスンは、動画「Left Sided Heart Failure」を教材にしています。繰り返し出てくる語は次のとおりです：blood, failure, pressure, valve, overload。この動画には、シャドーイング用の文が230文、単語が2644語あります。音声の長さは18:57です。話す速さは1分あたり約140語で安定しており、シャドーイングしやすいペースです。英語の頻出3,000語に含まれる単語は79%だけなので、語彙は難しめです。

この動画の重要語彙

動画に出てくる覚えておきたい単語15語を、発音と意味つきで紹介します。

単語	発音	意味
valve 名詞	/ˈvælv/	バルブ
overcome 動詞	/ˌəʊ.vəˈkʌm/	克服する, 征服する
muscle 名詞	/ˈmʌs.əl/	筋肉, 筋
thick 形容詞	/θɪk/	太い, 厚い
narrow 形容詞	/ˈnæɹəʊ/	狭い
vessel 名詞	/ˈvɛsəl/	船舶
lung 名詞	/ˈlʌŋ/	肺臓, 肺
output 名詞	/ˈaʊtpʊt/	出力
pump 名詞	/pʌmp/	ポンプ, 喞筒
oxygen 名詞	/ˈɑksɪd͡ʒən/	酸素
symptom 名詞	/ˈsɪm(p)təm/	症状, 症候
tissue 名詞	/ˈtɪʃ.(j)u/	織物
fluid 名詞	/ˈflu.ɪd/	流体, 液体
hollow 形容詞	/ˈhɑloʊ/	空っぽ, くぼんだ
fatigue 名詞	/fəˈtiːɡ/	疲労, 疲れ

動画に出てくる句動詞

単語	意味
go back 動詞	戻る, 帰る
go up 動詞	上がる, 登る
lie down 動詞	横になる, 臥す
write down 動詞	書き留める, 記す

繰り返し練習したい文

動画に出てくる短く完結した文です。日常会話でそのまま使えます。

Let's jump straight into it.
Alright, to begin, let's orientate ourselves.
We don't have this arterial hypertension.
How can we overcome this?
What do I mean by that?

この動画の文法

話し手がよく使っている文型を、動画の実際の表現とともに紹介します。

文型	動画での表現
現在完了形 have/has + 過去分詞 — 過去の出来事が今も関係している	I've separated · have increased · we've blocked
受動態 be + 過去分詞 — 誰がするかより、何が起きるかに焦点を当てる	is actually called · is decreased · is blocked
関係詞節 who / which + 節 — 人や物について情報を加える	alveolus, which is · ventricle which means · one which is

注意したい発音

話し手はyou've, can't, we'reなど、短縮形や弱形を47回使っています。聞こえたとおりの短い形で発音しましょう。

「th」の音: thick /θɪk/, breathe /bɹiːð/, thickness /ˈθɪknəs/, pathology /pəˈθɒləd͡ʒi/, chemotherapy /ˌkiːməʊˈθɛɹəpi/
「sh」と「zh」の音: circulation /ˌsɝkjʊˈleɪʃən/, tissue /ˈtɪʃ.(j)u/, reduction /ɹɪˈdʌk.ʃən/, representation /ˌɹɛp.ɹə.zɛnˈteɪ.ʃən/, martial /ˈmɑɹʃəl/
長い単語（アクセントの位置に注意）: circulation /ˌsɝkjʊˈleɪʃən/, respiratory /ɹɪˈspɪ.ɹət.ə.ɹi/, metabolic /mɛtəˈbɒlɪk/, representation /ˌɹɛp.ɹə.zɛnˈteɪ.ʃən/, mechanism /ˈmɛk.ə.nɪ.zəm/

日本語話者が苦手な音：

/r/ と /l/ の区別 — /l/ は舌先を歯茎につけ、/r/ はどこにもつけない: parallel /ˈpæ.ɹəˌlɛl/, relax /ɹɪˈlæks/, martial /ˈmɑɹʃəl/, pulmonary /ˈpʌl.məˌnɛ.ɹi/, ventricle /ˈvɛn.tɹɪk.əl/
/v/ — /b/ にならないように、上の歯を下唇に当てる: valve /ˈvælv/, overcome /ˌəʊ.vəˈkʌm/, vessel /ˈvɛsəl/, overload /ˌəʊvəˈləʊd/, ventricle /ˈvɛn.tɹɪk.əl/
/f/ — 「フ」ではなく、上の歯と下唇で出す: fluid /ˈflu.ɪd/, fatigue /fəˈtiːɡ/, refer /ɹɪˈfɜː/, define /dɪˈfaɪn/, functional /ˈfʌŋkt͡ʃənəl/

この動画での練習方法

まず声を出さずに動画を最後まで聞き、知らない単語をメモします。
通常の速度で一文ずつシャドーイングし、話し手のリズムに合うまで繰り返します。
自分の声を録音して元の音声と比べます。valve, overcome, muscleなどの単語に特に注意しましょう。

シャドーイングとは？英語上達に効果的な理由

シャドーイング（Shadowing）は、もともとプロの通訳者養成プログラムで開発された言語学習法で、多言語習得者として知られるDr. Alexander Arguelles によって広く普及されました。方法はシンプルですが非常に効果的：ネイティブスピーカーの英語を聞きながら、1〜2秒の遅延で声に出してすぐに繰り返す——まるで「影（shadow）」のように話者を追いかけます。文法ドリルや受動的なリスニングと異なり、シャドーイングは脳と口の筋肉が同時にリアルタイムで英語を処理・再現することを強制します。研究により、発音精度、抑揚、リズム、連音、リスニング力、そして会話の流暢さが大幅に向上することが確認されています。IELTSスピーキング対策や自然な英語コミュニケーションを目指す方に特におすすめです。

シャドーイングのやり方: ステップ別の完全ガイドを読む →

シャドーイング練習: Left Sided Heart Failure - 動画で英語スピーキングを学ぶ

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