房性早搏前PR段和ST段压低患者的临床和心电图分析

目的观察房性早搏(PAC)前PR段和ST段压低患者的临床和心电图(ECG)特征。方法分析PAC前PR段和ST段压低332例(观察组)的临床和ECG表现,并与558例PAC前无PR段和ST段压低(对照组)进行比较。结果①PR段和ST段压低导联分布广,以Ⅰ、Ⅱ、Ⅲ、aVF、V2～V6导联常见,V3、V4导联出现率最高,且PR段和ST段压低最显著。②观察组的PAC有如下特点:联律间期(CI)短且固定、提前指数(PI)小、多数呈PonT现象,PAC的P(P′)波时限长、P′波多呈高尖或切迹,绝大多数PAC的PR段和ST段也压低;PAC成对及连续发生或阵发心房扑动和心房颤动均较多;PAC发生前心动周期多不稳定;观察组年龄较大,窦性P波电压较高及时限较大,房内阻滞较多。以上指标与对照组比较差异均有显著性意义。结论 PR段和ST段压低是心房电不稳定的表现,具有这一特征的PAC属高危PAC,常常伴有其他更为严重的房性心律失常。

The clinical and ECG analysis of patients with depression of PR segment and ST segments before premature atrial contraction

Objective To observe the clinical and electrocardiogram （ECG） characters of patients with the depression of PR segment and ST segment before the premature atrial contraction （PAC）. Methods The clinical and ECG charac- ters of 332 cases, who had depression of PR segment and ST segment before the PAC （observation group） , were analysed and compared with that no depression PR segment and ST segment before the PAC （the compared group）. Results （~ The lead distribution of the depression PR segment and ST segment before the PAC was wide and leads I , H , m ,aVF,V2 V6 were familiar. The occurrence frequency of V3 and V4 was the highest, and the depression of PR segment and ST seg- ment of which were the most obvious. （~）The coupling interval （CI） of PAC in the observation group was short and fixed, and most of which had P on T phenomenon . The duration of PAC＇s P（P＇） wave was long. Its premature index （PI） was small and many P＇ waves were high-tip or with notch. Most of the PAC had depression PR segment and ST segment. The occurrence frequency of double PAC, continuously or paroxysmal atrial flutter and atrial fibrillation were higher. The cardi- ac cycles before PAC were mostly unstable. The voltage of sinus P wave was higher and the duration was longer. There was more intra atrial block. The differences between the data of the two groups were all very significant. Conclusion PR segment and ST segment depression before the PAC indicate unstable atrial electric activity. In this case, the PAC is highrisk and may develops into more serious atrial arrhythmias.