什么是心律失常?
The term "心律失常" refers to any problem in the rate or rhythm of a person’s heartbeat. 在心律失常期间, 电脉冲可能太快了, 心跳过慢或不稳定导致心跳不规律的.
When the heart doesn't beat properly, it can't pump blood effectively. 当这种情况发生时, 肺部, brain and all other organs can't work properly and may shut down or be damaged. 查看心律失常的动画.
心律失常的类型
The normal heart is a strong, muscular pump a little larger than a fist. 它把血液输送到身体的各个部位.
To understand how the heart pumps, learn about: Structure of the heart
心脏有四个腔室，四个瓣膜
The heart has four chambers, two on the right and two on the left:
- Two upper chambers are called atria (one is called an atrium).
- 两个较低的腔室称为心室.
The heart also has four valves that open and close to let blood flow in only one direction when the heart contracts (beats). 这四个心脏瓣膜分别是:
- Tricuspid valve, located between the right atrium and right ventricle
- Pulmonary or pulmonic valve, between the right ventricle and the pulmonary artery
- Mitral valve, between the left atrium and left ventricle
- Aortic valve, between the left ventricle and the aorta
Each valve has a set of flaps (also called leaflets or cusps). The mitral valve has two flaps; the others have three. Blood flow occurs only when there's a difference in pressure across the valves, 是什么导致它们打开. Under normal conditions, the valves allow blood to flow in only one direction.
The heart pumps blood to 肺部 and to all the body's tissues by a sequence of highly organized contractions of the four chambers. For the heart to function properly, the four chambers must beat in an organized way.
心脏的电系统
电子信号控制泵
The heart beat (contraction) begins when an electrical impulse from the sinus node (also called SA node) moves through the heart's muscle tissue. The SA node is sometimes referred to as the heart's "natural pacemaker" because it starts the impulses for the heartbeat.
The normal electrical sequence begins in the right atrium and spreads throughout the atria to the atrioventricular (AV) node. 从房室结, electrical impulses travel down the Bundle of His and through the Purkinje fibers causing the ventricles to contract.
The normal heart beats in a regular manner because electrical impulses cause a sequence of organized contractions. In an adult, a normal heart beats 60 to 100 times a minute.
心电图(ECG或EKG) 很简单, painless procedure that records the heart’s electrical activity and can help diagnose 心律失常s (abnormal heart rhythms).
心律失常(心律失常)
心律失常是指心跳异常. The term "心律失常" refers to any change from the normal sequence of electrical impulses.
Some 心律失常s are so brief (such as a temporary pause or premature beat) the overall heart rate or rhythm isn't greatly affected. 但如果心律失常持续沙巴足球体育平台更长, 它们可能会使心率过慢, too fast or erratic so the heart pumps less effectively.
- A fast heart rate (in adults, more than 100 beats per minute) is called 心动过速.
- A slow heart rate (less than 60 beats per minute) is referred to as 心动过缓.
原因
正常情况下, the heart's most rapidly firing cells are in the sinus node, 使该区域成为天然的起搏器. 在某些情况下, almost all heart tissue can start an impulse of the type that can generate a heartbeat.
- Cells in the heart's conduction system can fire automatically and start electrical activity. This activity can interrupt the normal order of the heart's pumping activity.
- Secondary pacemakers elsewhere in the heart provide a "back-up" rhythm when the sinus node doesn't work properly or when impulses are blocked somewhere in the conduction system.
心律失常可由以下原因引起:
- A delay or blockage of the electrical signals that control the heartbeat.
- 心脏的另一部分起起搏器的作用.
- Changes to heart tissue cause by changes in blood flow, damage to the heart’s electrical system or stiffening or scarring of the heart tissue.
- 过度的努力、紧张或压力.
- An imbalance of fluids, hormones or electrolytes in the blood.
- 某些心脏药物.
心律失常发生在:
- The heart's natural pacemaker develops an abnormal rate or rhythm.
- The normal conduction pathway is interrupted or changed.
- 心脏的另一部分起起搏器的作用.
