传导
正常的心电活动，开始于窦房结，并由此发出冲动，先后兴奋心房和心室，使得心脏收缩
单词
窦房结 Sinoatrial node
房室结 Atrioventricular node
房室束 Bundle of his
左/右束支 Left/ right bundle branch
浦肯野纤维 Pukinje fibres
认识窦房结
Sinoatrial (SA) node
相当于是一个总司令，发布命令，位于上腔静脉和右心房的交界处，由交感神经和副交感神经系统控制。
The main pacemaker that initiates each heartbeat 。It is located at the junction of the superior vena cava and the right atrium.
The SA node generates electrical impulses at 60 to 100 times per minute and is controlled by the sympathetic and parasympathetic nervous systems.
描述心脏节律
Normal 正常
Irregular 不规则的
Bradycardia brady- slow 心动过缓
Tachycardia tachy- fast 心动过速
初步认识心电图
P波 P wave 表示心房的除极化
QRS波 QRS complex 表示心室除极化
PR间期 PR interval
ST段 ST segment
QT间期 QT interval
T波 T wave 心室的复极化形成
纵轴： 每一小格代表0.1mv，
横轴： 每一大格分为5小格，每小格0.04s
心率： 60 ÷ R-R间距
正常窦性心律
Normal sinus rhythm
Rhythm originates from the SA node.
Atrial and ventricular rhythms are regular.
Atrial and ventricular rates are 60 to 100 beats/minutec.
PR interval and QRS width are within normal limits.
正常窦性心律
窦性心律一定是由窦房结发出来的，一定有P波，心率在60-100次/分
窦性心动过缓：心率＜60次/分
窦性心动过速：心率＞100次/分
节律
通俗说，正常节律就是各种同类波距离相等
上图中：Normal sinus rhythm
Both atrial and ventricular rhythms are essentially regular (a slight variation in rhythm is normal).
Atrial and ventricular rates are both 83 beats/ minute.
There is one P wave before each QRS complex, and all P waves are of a consistent morphology, or shape.
每个QRS波前都有一个P波，所有的P波都具有一致的形态或形状。
The PR interval measures 0.18 seconds and is constant;
the QRS complex measures 0.06 seconds and is constant.
窦性心动过缓
Sinus bradycardia
措施： Interventions
找到原因，若是药物引起就要停掉.
Withhold the medication
硫酸阿托品可以提高心率 ，但避免过度使用.
Administer atropine sulfate
Avoid additional doses of it
如果药物效果欠佳，根据发病原因，安装临时起搏器或永久起搏器.
Apply a noninvasive pacemaker or permanent pacemaker
