2　Sinus arrhythmias窦性心律失常

1)Sinus tachycardia (Fig.2-1) 窦性心动过速（图2-1）

The normal sinus rate at rest is generally between 60bpm and 100bpm. Sinus tachycardia means that sinus rate exceeds 100bpm. On the ECG, the P wave is upright in leads Ⅰ , Ⅱ , aVF,and is down in lead aVR, meanwhile R-R intervals is constant and regular. Sinus tachycardia can have many causes, such as physiological or pathological causes, including tension, sport, fever,caffeine, cocaine, anemia, heart failure and so on.

静息状态下正常窦性心律一般介于60～100次/分。窦性心动过速的频率>100次/分，心电图表现为P波在Ⅰ、Ⅱ、aVF导联直立，aVR导联负向，R-R间期恒定规整。窦性心动过速的原因有多种，如生理性和病理性病因，包括紧张、运动、发热、咖啡因、可卡因、贫血、心力衰竭等。

Fig.2-1　Sinus tachycardia (Note: heart rate 128bpm)

图2-1　窦性心动过速：心率128次/分