QT离散度对室性心律失常发生的预测价值的再探讨

研究体表心电图QT离散度(QTd)对室性心律失常的发生是否有预测价值。将204例入选心脏病例的QTd按级差5ms分段,计算各时段病例中频发室性早搏(VPB≥30次/小时)以及室性心动过速(VT)+心室颤动(VF)的发生率。以各时段QTd的上限值为变量,对各时段室性心律失常的发生率与QTd上限值进行相关性研究。将上述室性心律失常者分设为VPB组(n=52)和VT+VF组(n=46)。在其余入选病例中选择未发现明显室性心律失常者(VPB<5次/小时)50例设为疾病对照组。另设正常对照组(n=50)。对各组QTd进行组间比较。结果:各时段VPB及VT+VF的发生率与QTd上限值无明显相关性(r1=0.2091,r2=0.1684,P>0.05)。VPB组及VT+VF组的QTd虽明显大于正常对照组(P<0.01),但与疾病对照组比较无显著差异(P>0.05)。结论:QTd对室性心律失常的发生似乎无预测价值。

Further Research About QT Dispersion''''s Predictive Value to Incidence of Ventricular Arrhythmia

To estimate the predictive value of QT dispersion(QTd) to the occurrence of ventricular arrhythmia with surface synchronous 12-lead electrocardiogram,204 patients with different cardiac diseases were selected. Their QTd was assigned to different time intervals in length sequence and the step difference between each of two adjacent intervals was 5 ms. The incidence rates of frequent ventricular premature beat(VPB)(VPB≥30 beats per hour), ventricular tachycardia (VT) and ventricular fibrillation(VF) in each interval were calculated respectively and the correlations between incidence rates of ventricular arrhythmia and QTd were studied. Patients with ventricular arrhythmia mentioned above were divided into Group VPB (n=52) and Group VT+VF (n=46). 50 patients without obvious ventricular arrhythmia (VPB<5 beats per hour) among the remainding 106 patients were selected as disease controlled group (Group D).Normal controlled group(Group N) was also set. QTd was compared among the four groups. Results: ①There was no significant correlation between the morbidities of ventricular arrhythmia and QTd(r_1=0.2091,r_2=0.1684, P>0.05). ② The QTd in Group VPB and Group VT+VF was significant longer than Group N (P<0.01), but it was similar to Group D(P>0.05). Conclusion: It seems that QTd has no predictive value of incidence of ventricular arrhythmia