文档介绍：Properties of cardiac tissue 心脏组织的特性
Automaticity 自律性: ability to initiate an impulse spontaneously and continuously.
Excitability兴奋性: ability to be electrically stimulated.
Contractility收缩性: ability to respond mechanically to an impulse.
Conductivity传导性: ability to transmit an impulse along a membrane in an orderly manner.
Conduction system: a brief review传导系统
P wave begins with the firing of the SA node and represents depolarization去极化 of the fibers of the atria心房, resulting in atrial contraction心房收缩.
The QRS complex represents depolarization去极化 of the ventricles心室, resulting in ventricular contraction心室收缩.
The T wave represents repolarization复极of the ventricles心室, or the time at which the ventricles return to the prestimulated state.
Conduction system: a brief review
Intervals波间隔between these waves reflects the lengths of time it takes for the impulses to travel from one area of the heart to the other.
The PR interval represents the period during which the impulse spreads through the atria, AV node房室结, bundle of His希氏束, and Purkinje浦肯野纤维.
The QRS interval represents the time it takes for depolarization去极化of both ventricles.
The QT interval represents the time it takes for complete depolarization除极and repolarization复极of the ventricles.
Dysrhythmia
Dysrhythmia is an abnormal cardiac rhythm in terms of the frequency of the impulse频率, rhythm节律, origin site起源部位, conduction velocity传导速度and excitement order激动次序.
Classification of Dysrhythmia 心律失常的分类
Abnormal impulse formation 冲动形成异常
sinus dysrhythmia 窦性心律失常
sinus tachycardia窦性心动过速
sinus bradycardia窦性心动过缓
窦性心律不齐
sinus arrest窦性停搏
ectopic rhythm异位心律
Passive ectopic rhythm被动性异位心律
Escaped 逸博
Escapedrhythm 逸博心律
Active ectopic rhythm主动性异位心律
期前收缩Premature Contraction
Paroxysmal tachycardia阵发性心动过速
atrial flutter房扑， atrial fibrillation房颤
ventricular flutter室扑， ventricular fibrillation室颤
Abnormal impulse comduction 冲动传导异常
Physiological:生理性： interference and separation of AV干扰和房室分离
pathological病理性：
block of S