心肌组织速度成像评价慢性心力衰竭患者心室收缩不同步性及其与QRS间期相关性的研究

Assessment of ventricular asynchrony and correlation with QRS duration in the patients with chronic heart failure by tissue velocity imaging

目的应用心肌组织速度成像(TVI)评价慢性心力衰竭患者左心室收缩不同步性与心电图QRS间期的关系。方法选取心功能NYHAⅢ～Ⅳ级的扩张性心肌病(DCM)患者60例作为研究对象,依QRS间期分为DCMⅠ组21例(QRS间期<120ms)、DCMⅡ组21例(QRS间期120～150ms)和DCMⅢ组18例(QRS间期>150ms);对照组为30例健康志愿者。分别测量QRS波起点到主动脉瓣血流频谱起始点时间(Q-AO)和到肺动脉瓣血流频谱起始点时间(Q-Pulm),采用两者的差值即心室间机械延迟参数(IVMD)评价左右心室间的同步性。获取左心室各节段心肌TVI曲线,测量各节段从心电图QRS波起点到TVI曲线S波起点的时间(Q-Sb),取18节段Q-Sb的标准差作为左心室内同步性指数(TSI),取各室壁基底段和心尖段Q-Sb的差值作为各室壁内的同步性指数(RSI)。结果以IVMD>40ms为判定左右心室间不同步的截点值,在DCMⅠ、Ⅱ、Ⅲ组中观察到室间非同步性的患者分别为4、10和13例,发生率差异无统计学意义(P<0.01),且IVMD与QRS间期密切相关(r=0.73,P<0.01)。DCM组TSI和RSI较对照组显著延长(P<0.01),但TSI和RSI与QRS间期无明显相关性。结论DCM患者心室间非同步性和QRS间期相关,左心室各室壁间与各室壁内非同步性和QRS间期无明显相关性。

Objective To analyze the relationship between the left ventricular （LV） asynchrony and the QRS duration by the tissue velocity imaging （TVI）. Methods Sixty patients with the dilated cardiomyopathy （DCM, New York Heart Association class Ⅲ-Ⅳ ） and 30 healthy subjects were studied. The heart failure patients were classified into three groups ： Group I included 21 patients with QRS duration 〈 120 ms; Group Ⅱ consisted of 21 patients with QRS duration between 120 - 150 ms and 18 patients with QRS duration 〉 150 ms were in the Group Ⅲ. The interventricular mechanical delay （IVMD）, the difference between the aortic pre-ejection time and the pulmonary pre-ejection time was measured. The patients underwent the TVI to get myocardial regional velocity curves. The duration from the beginning of QRS in ECG wave to the beginning of S wave（Q-Sb） was assessed and the total synchronicity indexes （TSI） of left ventricle was calculated. Results The IVMD 〉 40 ms was considered as the cut-off value for interventricular asynchrony. There were 4, 10 and 13 patients with interventricular asynchrony in DCM I , lI and II1 respectively （P 〈 0.01 ）. The IVMD was related with QRS duration （ r = 0. 73, P 〈 0.01 ）. The TSI in DCM groups were significantly increased compared with that in control groups （ P 〈 0.01 ）. The difference within DCM groups was significantly. The TSI was not directly related with the duration of QRS. Conclusions Interventricular asynchrony is related with QRS duration in DCM patients, but not the degree of LV asynchrony.