英語聽力文摘471 你的心臟夠強(qiáng)大嗎？
Don: Yaël, isn't normal heart rate somewhere between sixty to one hundred beats per minute?
Yaël: That's right, Don. Why?
D: This would be the one time you don't correct me. My heart rate is only 44 beats per minute. That means I have bradycardia. Oh, Yaël, I may be dying.
Y: Hold up! Yes, bradycardia is the term for a heart rate slower than about sixty beats per minute, but bradycardia doesn’t necessarily mean you’re not in perfectly good health. In well-conditioned athletes, bradycardia is a result of being in such good shape that the heart beats more efficiently, and so it doesn’t need to beat as quickly.
An athlete may have a heart rate as slow as thirty and not show any signs of problems. Also, deep relaxation, such as sleep, slows the heart down.
D: Yeah, yeah! Tell me about the bad news.
Y: Well, bradycardia can also be caused by certain medications, by other disorders such as hyperthyroidism, and by dysfunction of the sinus node. I don’t mean the hollow space behind your nose, but the node inside your heart. The sinus node powers your heart by electrical impulses.
Dysfunction of the sinus node then can cause the heart to beat too slowly to keep up with your body’s need for blood. Lightheadedness, weakness, and fainting are symptoms that a heart may be beating too slowly. In such cases, doctors will remove problem medications, correct the underlying disorder, or insert a pacemaker that fills in for the sinus node.
If symptomatic bradycardia goes untreated, it could lead to death, but that’s easy enough to prevent–just go see your doctor.
心動過緩
Don: Yaël,正常人的心跳次數(shù)是不是60~100次/分?
Yaël: 是啊。有什么問題嗎?
D: 難得有這么一次你沒有糾正我。我的心率僅僅是44次/分，我心動過緩!我的天，Yaël，我很可能就要死啦!
Y: 穩(wěn)住啦!確實，心動過緩專指心臟跳動次數(shù)慢于60次/分。但是，心動過緩并不就是說你不健康。對于那些身體非常健康的運動員們來說，心動過緩的情況非常普遍。之所以會這樣是由于他們的心臟能夠進(jìn)行更加高效的跳動，因而，運動員心臟無需跳得有多快。
運動員的心率一般會低至30次/分，而他們的身體沒有任何問題。同時，在深度放松的情況下，就比如說睡覺，心率會自然而然的降低。
D: 嗯，那給我講講不好的方面。
Y: 額，心動過緩也可能是由特殊的藥物治療、甲狀腺機(jī)能亢進(jìn)一類的機(jī)體功能紊亂、竇房結(jié)(位于右心房外膜上)功能障礙——竇房阻滯等原因引起的。竇房結(jié)并不是指你鼻后中空的地方(此處是因sinus的意思為“穴”，談話者將sinus與node分開來講)，而是指心臟內(nèi)的一個結(jié)點。竇房結(jié)通過電脈沖為心臟提供動力。
竇房結(jié)的功能障礙會使心臟跳動過緩，而無法滿足身體對血液的需求。心臟如果跳動過緩就可能會出現(xiàn)頭暈、身體疲乏、暈厥等癥狀。如果出現(xiàn)這樣的癥狀，醫(yī)生會采取一定的藥物治療、調(diào)節(jié)機(jī)體功能，或是為竇房結(jié)安裝人工心臟起搏器。
由心動過緩引發(fā)的癥狀治療無效時會導(dǎo)致死亡，但是，這樣的情況也相當(dāng)容易預(yù)防——看醫(yī)生就得嘞!
