扩张型心肌病窦性心率震荡及QT离散度与心功能变化的相关性

目的 探讨扩张型心肌病(DCM)患者窦性心率震荡(HRT)及QT离散度(QTa)与心功能变化的相关性及临床价值.方法 81例临床诊断DCM伴室性早搏患者,按心功能分级分组:A组(心功能Ⅰ～Ⅱ级)34例,B组(心功能Ⅲ～Ⅳ级)47例,并选取同期健康人群30名为对照.24 h动态心电图检测各组HRT参数:震荡初始(TO)和震荡斜率(TS),体表12导联心电图测定QTd,同时超声心动图测量左室射血分数(LVEF)、左室舒张末内径(LVEDD),E、A峰值及E/A比值;各组间比较且对TO、TS、QTd与心功能指标进行相关性分析.结果 与健康对照组比较,DCM A、B两组患者TO值显著增高0.38(-0.99～1.85)%比1.82(0.02～3.92)%比(-4.03±3.48)%,P＜0.01];TS值明显降低(P＜0.01),QTd增加(54±15)ms比(71±18)ms比(32±13)ms];且随着心功能恶化QTd增加越趋明显.TO与LVEF呈负相关(r=-0.701,P＜0.05),与LVEDD呈正相关(r=0.621,P＜0.05),与E峰及A峰值无相关性;TS和QTd与LVEF、LVEDD也有显著相关性(均P＜0.05).结论 DCM患者HRT现象减弱,HRT和QTd变化与患者心功能恶化相一致,联合检测对评价DCM患者自主神经功能状态及预后有较高的临床价值.

Relationship among heart rate turbulence, QT dispersion and heart function in patients with dilated cardiomyopathy

Objective To explore the relationship among heart rate turbulence (HRT), QT dispersion (QTd) and heart function in patients with dilated cardiomyopathy (DCM) and assess its clinical value. Methods A total of 81 DCM patients with ventricular premature contraction (VPC) were divided into two groups according to heart function: Group A (NYHA class Ⅰ -Ⅱ , n = 34) and Group B (NYHA class Ⅲ-V, n =47). Thirty out-patient control cases were chosen from those undergoing regular physical examination. 24hour holter was performed to monitor turbulence onset ( TO ) and turbulence slope (TS).Electrocardiogram (ECG) was used to assess QTd. Meanwhile left ventricular ejection fraction ( LVEF),left ventricular end-diastolic dimension ( LVEDD), E and A-wave peak velocities, E/A were measured by echocardiogram. After a comparison of all indicators in each group, an investigation was conducted to discern the relationship among HRT, QTd and heart function. Results Compared with normal group, TO significantly increased in DCM A and B group: 0. 38 ( - 0.99 ～ 1.85 ) % vs 1.82 ( 0. 02 ～ 3.92 ) % vs ( -4. 03 ± 3.48 )%, P ＜ 0. 01]. TS significantly decreased while QTd increased. The trend of QTd addition was apparent along with heart failure. TO was negatively correlated with LVEF ( r = -0. 701, P ＜0. 05 ) but positively correlated with LVEDD ( r =0. 621, P ＜0. 05 ). There was no correlation with E and A-wave peak velocities. TS and QTd also had an obvious correlation with LVEF and LVEDD ( all P ＜ 0. 05 ) .Conclusions HRT is dramatically blunted in DCM patients and has a certain correlation with cardiac dysfunction. A combined test of HRT and QTd is a sensitive and indirect index in assessing autonomic nerve functions. It has a high clinical value of predicting the prognosis.