2009年6月30日 星期二

How Heart Disease Works

by Carl Bianco, MD

Please copy/paste the following text to properly cite this HowStuffWorks article:
Bianco, Carl. "How Heart Disease Works." 01 April 2000. HowStuffWorks.com. 30 June 2009.
Inside this Article
Introduction to How Heart Disease Works
Atherosclerosis: Are You at Risk?
Angina
Heart Attack
Lots More Information
See all Cardiovascular Conditions articles
Heart Effects


More Health Videos »
Heart Health Image GallerySee more heart health pictures.
Heart disease is the leading cause of death in the U.S. At some point in your life, either you or one of your loved ones will be forced to make decisions about some aspect of heart disease. Knowing something about the anatomy and functioning of the heart, in particular how angina and heart attacks work, will enable you to make informed decisions about your health.
Heart disease can strike suddenly and require you to make decisions quickly. Being informed prior to an emergency is a valuable asset to you and your family.
In this article we will discuss various heart diseases and how they can lead to a heart attack, or even a stroke. We will also look at how heart attacks are treated and what you should do to prevent heart disease.
Additional ReadingThis article is preceeded by two others that will be extremely helpful to you in understanding heart disease:
How the Heart Works
How Diagnosing Heart Disease Works Reading these two articles prior to reading this one will give you the background you need on the anatomy and functioning of the heart.
The basics Coronary Artery Disease (CAD), Coronary Heart Disease (CHD), Ischemic Heart Disease (IHD) and Arteriosclerotic Cardiovascular Disease (ASCVD) are all different names for the same disease. This disease is caused by atherosclerosis, which is a buildup of fatty deposits (atheroma) in the coronary arteries. See the figure below:
Photo courtesy -->CAPTION -->
Coronary arteries supply blood to the heart muscle. When a blockage occurs in one of these arteries, blood flow to the heart muscle is decreased. This becomes most evident during exertion. During exertion, the heart muscle is working harder and needs more oxygen-enriched blood than usual. By preventing the much needed increase in blood flow, the blockage deprives the heart muscle of oxygen thereby causing the heart muscle to hurt. This chest pain is called angina or Angina Pectoris. When the heart muscle goes without sufficient oxygen, the muscle is said to be ischemic. If cell death occurs it is called infarction. Since a heart attack is cell death of heart muscle (myocardium), it is called a Myocardial Infarction (MI). The condition that causes CAD, angina and heart attacks is called atherosclerosis.
Arteriosclerosis is a more general term for hardening of the arteries. Atherosclerosis is a type of arteriosclerosis that causes a buildup of fatty material (referred to as atheromas and plaques) along the inner lining of arteries. Depending on where these blockages occur, they can cause a number of different outcomes:
If the blockage occurs in a coronary artery, it causes chest pain (angina).
If the blockage is complete, it can cause a heart attack (Myocardial Infarction or MI).
If the blockage occurs in one of the arteries near the brain, a stroke can occur.
If a blockage occurs in a leg artery, it causes Peripheral Vascular Disease (PVD) and can cause pain while walking called intermittent claudication.
­Atherosclerosis takes many years, even decades to develop and the condition can easily go unnoticed. Sometimes symptoms such as angina will gradually indicate the condition. However, it can also become evident in a sudden and severe way, in the form of a heart attack.
Let's take a look at some of the risk factors for atherosclerosis. Some of these factors are things you can control. By being proactive, you could reduce your risk.

滿水之杯,裝不進「水和智慧」!

學習活得好,勝過功課好!
文/戴晨志 2009.01.08
快樂,是可以選擇的!當我們跟不同的人相處,我們試著看他的長處,也秉著「肯定自己、接納對方」的心情,我們就會更加快樂!
千萬不能「埋怨他人、封閉自己」啊!
最近有一位大學女生告訴我說,她的英文被老師「當掉」了。
問她為什麼?她說,因為那個英文男老師很色,第一次來上課就一直聊天,又開黃腔、講黃色笑話,真是很無聊,一看到他就很討厭;所以她很不喜歡這男老師的課,最後,就被老師當掉了!
唉,這是多麼可惜呀!英文被當掉,明年還要重修一次,多划不來呀!
記得我在美國念碩士時,我知道我的功課不夠好,也沒有辦法和其他美國同學一樣地搶答、辯論或是談笑風生;而且,有一男教授很嚴格、很有權威,打起分數,更是不留情面。怎麼辦呢?我不能讓教授覺得我程度不好,而把我「當掉」呀!我必須「主動打開僵局」!
於是,我決定「主動親近教授」。在教授的「office hour」,也就是「在辦公室指導學生的時間」,我一定準備問題去請教這名教授,讓他知道,我是十分努力、用功的外籍學生,只是英文表達能力不夠好而已。
而且,在教授上課前,我常陪著教授從辦公室,踏著白雪,走到教室,一路請教他;而在下課後,當全班同學已經鳥獸散時,我又陪著教授,踏著白雪,走回辦公室。您想想看這幅畫面--「縮著身子,陪著老師、踏著白雪一起走路、一路請教老師」,那是多麼難得的「師生之情」啊!
或許有人會覺得我「很狗腿」、「很噁心」或「很虛偽」,可是,這些舉動,會讓老師看見學生的「虛心求教」和「尊師重道」呀;即使是在寒冷的冬天,老師的心和我的心,也都會覺得無比溫暖呀!
後來,那最嚴格的一科,我得了「B」,過關了。可是我們班上另外兩名老中,他們的命運就不一樣了,他們都拿了「F」,被教授當掉了!我問他們:「我不是已經從助教那兒硬拗來一些考古題,事前拿給你們看了嗎?」
我印象很深刻,那兩名老中回答我說--他們也曾去請教教授,可是那教授的態度很「歧視台灣學生」,在對他們講話時,教授的雙腳竟「蹺在桌上」,還「咬著蘋果」,一副很不屑的樣子。
我不清楚那教授是不是會「歧視台灣學生」?根據我的經驗是「不會」!或許,只是他們自己的感覺吧!可是,即使老師有一點歧視,我們為什麼要「擴大老師的缺點、縮小他的優點」呢?我們可以「主動接近老師、多欣賞他的優點」,讓師生的關係逐漸改善啊!
有句話說:「當我們看不順眼的人愈來愈多時,看我們順眼的人,就會愈來愈少!」的確,假如我們看不順眼老師、看不順眼老闆,相對地,老師或老闆也會看我們不順眼呀!
因 此,「角色扮演」很重要。一個學生或部屬,都沒有資格瞧不起老師和上司,畢竟他們的經驗都比我們豐富,也都坐上了那個位子;他們即使沒有真才實學,但多少都有值得我們學習之處啊!我們絕不能「恃才傲物、憤世嫉俗、孤芳自賞」,否則,就會像許多天才的命運一樣,斷送在「自認為自己很天才」之上呀!
我認識一女孩,國立大學物理系碩士第一名畢業,連男生都不是她的對手。後來,她獲得「全額獎學金」到紐約攻讀博士,系上的老師們相信,她一定可以在三年內(二十八歲前),拿到博士學位。
在紐約念書時,這女孩的成績幾乎都拿到「A」。可是,當她在做實驗研究時,與教授起了衝突。她堅持,是教授的見解有錯,結果,兩人水火不容;最後,博士資格考時,被教授當掉、退學了。
後來這女孩回台一陣,又申請到加州的一所名校,繼續攻讀博士;可是她在寫論文時,又批評教授的看法有誤,也嫌教授雜務太多、不專心做研究、懂得沒有比她多,實在「不夠格」來指導她。最後,這女孩又黯然離開了那加州大學。
您 知道嗎,這天才型的女孩、物理頂尖高手,在美國念了「四所大學博士班」,到了現在四十歲了,都沒有拿到學位。她總是在越洋電話中告訴家人--我的指導教授「很爛」、「沒什麼程度」、「沒資格指導論文」……如今,這女孩,噢,不,應說是「女士」,孤獨地回到台灣,天天窩在家裡,看書、看電視、睡覺,也不出去找工作,讓年邁的老爸頭痛不已。
事實上,我們的人生不能是一個「滿水的杯」,別人隨便一拍,水就滿溢出來;我們每天必須是個「倒空的杯」,虛心學習,讓更多的「水」和「智慧」,都能放進我們生命的「空杯」之中啊!
【本文摘錄自《戴晨志幽默加油站》推薦《少抱怨多實踐》時報文化】

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