What happens during a heart attack? - Krishna Sudhir

8,439,131 views ・ 2017-02-14

TED-Ed


Please double-click on the English subtitles below to play the video.

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Approximately 7 million people around the world die from heart attacks every year,
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and cardiovascular disease,
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which causes heart attacks and other problems like strokes,
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is the world's leading killer.
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So what causes a heart attack?
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Like all muscles, the heart needs oxygen,
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and during a heart attack, it can't get enough.
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Fatty deposits, or plaques,
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develop on the walls of our coronary arteries.
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Those are the vessels that supply oxygenated blood to the heart.
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These plaques grow as we age,
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sometimes getting chunky,
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hardened,
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or enflamed.
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Eventually, the plaques can turn into blockages.
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If one of the plaques ruptures or cracks,
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a blood clot will form around it in minutes,
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and a partially closed artery can become completely blocked.
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Blood flow is cut off to the cardiac muscle
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and the oxygen-starved cells start to die within several minutes.
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This is a myocardial infarction,
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or heart attack.
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Things can rapidly deteriorate in the absence of treatment.
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The injured muscle may not be able to pump blood as well,
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and its rhythm might be thrown off.
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In the worst case scenario, a heart attack can cause sudden death.
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And how do you know that someone is having a heart attack?
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The most common symptom is chest pain
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caused by the oxygen-deprived heart muscle.
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Patients describe it as crushing or vice-like.
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It can radiate to the left arm,
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jaw,
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back,
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or abdomen.
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But it's not always as sudden and dramatic as it is in the movies.
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Some people experience nausea
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or shortness of breath.
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Symptoms may be less prominent in women and the elderly.
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For them, weakness and tiredness may be the main signal.
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And surprisingly, in many people,
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especially those with diabetes, which affects the nerves that carry pain,
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a heart attack may be silent.
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If you think that someone might be having a heart attack,
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the most important thing is to respond quickly.
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If you have access to emergency medical services, call them.
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They're the fastest way to get to a hospital.
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Taking aspirin, which thins the blood,
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and nitroglycerin, which opens up the artery,
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can help keep the heart attack from getting worse.
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In the emergency room, doctors can diagnose a heart attack.
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They commonly use an electrocardiogram
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to measure the heart's electrical activity
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and a blood test to assess heart muscle damage.
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The patient is then taken to a high-tech cardiac suite
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where tests are done to locate the blockages.
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Cardiologists can reopen the blocked artery
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by inflating it with a balloon in a procedure called an angioplasty.
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Frequently, they also insert a metal or polymer stent
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that will hold the artery open.
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More extensive blockages might require coronary artery bypass surgery.
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Using a piece of vein or artery from another part of the body,
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heart surgeons can reroute blood flow around the blockage.
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These procedures reestablish circulation to the cardiac muscle,
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restoring heart function.
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Heart attack treatment is advancing,
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but prevention is vital.
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Genetics and lifestyle factors both affect your risk.
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And the good news is that you can change your lifestyle.
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Exercise, a healthy diet, and weight loss
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all lower the risk of heart attacks,
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whether you've had one before or not.
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Doctors recommend exercising a few times a week,
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doing both aerobic activity and strength training.
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A heart-healthy diet is low in sugar and saturated fats,
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which are both linked to heart disease.
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So what should you eat?
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Lots of fiber from vegetables,
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chicken and fish instead of red meat,
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whole grains and nuts like walnuts and almonds
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all seem to be beneficial.
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A good diet and exercise plan can also keep your weight in a healthy range,
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which will lower your heart attack risk as well.
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And of course, medications can also help prevent heart attacks.
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Doctors often prescribe low-dose aspirin, for example,
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particularly for patients who've already had a heart attack
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and for those known to be at high risk.
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And drugs that help manage risk factors,
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like high blood pressure, cholesterol, and diabetes,
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will make heart attacks less likely, too.
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Heart attacks may be common, but they don't have to be inevitable.
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A healthy diet,
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avoiding tobacco use,
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staying fit,
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and enjoying plenty of sleep and lots of laughter
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all go a long way in making sure your body's most important muscle
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keeps on beating.
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