扩张性心肌病心率变异性及QT离散度和心功能的关系

Correlation among cardiac function and heart rate variability,QT dispersion in patients with dilated cardiomyopathy

目的:探讨扩张型心肌病(DCM)患者,心率变异性(heart rate variability,HRV)及QT离散度(QTdispersion,QTd)与心功能的相关性。方法:45例临床诊断DCM患者,按NYHA心功能标准分级,A组(心功能Ⅰ～Ⅱ级)16例,B组(Ⅲ～Ⅳ级)29例;检测各组HRV时域指标、QTd、左室射血分数(LVEF)及左室舒张末期内径(LVDd),与正常对照组比较.并检测其相关性。结果:与正常对照组比较,DCM患者HRV各项时域指标显著降低(P<0.05～<0.001),QTd显著增加(P<0.001);且随着心功能恶化,HRV时域指标下降,QTd增加越趋明显(P均<0.001);HRV各时域指标与QTd及LVDd呈显著负相关(P<0.001),与LVEF呈显著正相关(P<0.001);QTd与LVEF及LVDd也育显著相关性(P<0.001)。结论:HRV和QTd变化与DCM患者的心功能恶化是一致的,对预测DCM患者预后有较高价值,是一种简单的无创评定方法。

Objective: To investigate the characteristic of heart rate variability (HRV) and QT dispersion (QTd) in patients with dilated cardomyopathy (DCM) and their relationships to cardiac function. Methods: A total of 45 patients with DCM were divided into two groups according to cardiac function: group A (NYHA class Ⅰ -Ⅱ , 16 cases), group B (NYHA class Ⅲ~Ⅳ,29 cases). Comparing differences of HRV parameters and QTd between two groups and also comparing them with normal group, then investigating the correlation among cardiac function and HRV parameters, QTd. Results: Comparing with normal group, HRV parameters significantly decreased (P<0. 05 ~<0. 001) and QTd obviously increased (P<0. 001) in patients with DCM. With cardiac function deteriorated, the changes of HRV and QTd were more significant ( P<0. 001) . HRV parameters had obvious negative correlation to QTd and LVDd (P<0. 001), and positive correlation to LVEF (P<0. 001) in patient with DCM. Similarly QTd also had obvious correlation to LVDd and LVEF (P<0. 001). Conclusion: It is reasonable to believe that HRV and QTd can be used as a sensitive and indirect index in assessing cardiac function in patients with DCM and they are simple methods to predict the prognosis.