老年缺血性心脏病患者跨室壁复极离散度与心功能的相关性研究

Correlation of transmural dispersion of repolarization and cardiac function in elderly patients with ischemic cardiac disease

摘要:

目的 探讨老年缺血性心脏病患者跨室壁复极离散度（TDR）与心功能之间的关系。方法 选择老年缺血性心脏病患者159例；同时收集同期健康体检者143例为对照组；试验组根据心脏超声心功能参数联合BNP定量评定心功能分级方程进行心功能分级，分为心功能Ⅰ?Ⅱ级亚组68例，Ⅲ级亚组55例，Ⅳ级亚组36例；以上病例均行12导联心电图检查，在心电图上分别测定T波峰末间期（Tp-e）、QTc、QTd、Tp-e/QTc，比较试验组与对照组、试验各亚组的Tp-e、QTc、QTd、Tp-e/QTc；行24h动态心电图，观察各病例室性心律失常发生情况。结果 （1）对照组心电图上各项指标与试验组各指标比较，试验组较对照组QTc显著延长（P＜0.05），Tp-e、QTd、Tp-e/QTc也显著延长（P＜0.01）；（2）心功能Ⅳ级组与Ⅰ?Ⅱ级组比较、Ⅳ级组与Ⅲ级组比较、Ⅲ级组与Ⅰ?Ⅱ级组比较，两者各指标间差异均具有统计学意义（P＜0.05）；（3）试验组恶性心律失常发生率较对照组高（15.7% vs 0.6%，P＜0.05）；试验组的Tp-e、QTd、Tp-e/QTc与恶性心律失常发生率呈正相关（P＜0.05），对照组的各指标与恶性心律失常发生率均无明显相关。结论 （1）老年缺血性心脏病TDR增大，发生室性心律失常的风险增加；（2）缺血性心脏病患者心力衰竭严重程度对TDR有显著影响，随着心功能减退，TDR逐渐增大；TDR增大可在一定程度上反映心肌组织损害的严重程度。

Abstract:

Objective To investigate the relationship of transmural dispersion of repolarization (TDR) with cardiac function in the elderly patients with ischemic cardiomyopathy. Methods A total of 159 elderly patients with ischemic cardiomyopathy identified by coronary angiography were enrolled in this study as test group, and another 143 volunteers receiving physical examination during the same period were subjected as controls. According to the cardiac function equation based on the echocardiographic parameters of cardiac function combined with brain natriuretic peptide (BNP), the test group was divided into 3 subgroups: class Ⅰ-Ⅱ (n＝68), class Ⅲ (n＝55), and class Ⅳ (n＝36). With the aid of standard 12-lead ECG, their Tp-e interval (an interval from the peak to the end of the T wave), QTc interval, QTd (QT dispersion), and Tp-e/QTc ratio were measured and calculated, then the results were compared between the subgroups. Dynamic electrocardiograhy (Holter monitor) was employed to observe the incidence of ventricular arrhythmia. Results (1)The Tp-e interval (P＜0.01), QTc interval (P＜0.05), QTd (P＜0.01), and Tp-e/QTc ratio (P＜0.01) were more longer or higher in test group than in the control group. (2) There were significant differences in the above indices between the class Ⅳ and class Ⅰ-Ⅱ subgroups, class Ⅳ and class Ⅲ subgroups, and class Ⅲ and class Ⅰ-Ⅱ subgroups (P＜0.05). (3) The incidence of malignant arrhythmia was obviously higher in the ischemic cardiomyopathy group than in control group (15.7 vs 0.6%, P＜0.05). There were positive correlations of Tp-e interval, QTd, and Tp-e/QTc ratio with arrhythmia incidence in the test group (P＜0.05). While these indices had no relationship with malignant arrhythmia in control group. Conclusion (1) In the elderly with ischemic cardiomyopathy, the larger their TDR is, the higher risk of ventricular arrhythmia they have. (2) For these patients, the severity of heart failure significantly affects their TDR, with cardiac dysfunction severer, and the TDR larger. So, the extent of TDR can partly reflect the severity of cardiac muscle tissue.