Zhang Yan, Chan Anna K Y, Yu Cheuk-Man, Lam Wynnie W M, Yip Gabriel W K, Fung Wing-Hong, So Nina M C, Wang Mei, Sanderson John E
Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR.
Am Heart J. 2005 Mar;149(3):497-503. doi: 10.1016/j.ahj.2004.05.054.
The aim of the study was to assess the degree of left ventricular (LV) asynchrony after myocardial infarction (MI) in patients with a narrow QRS complex using tissue Doppler imaging (TDI) and correlate this with the site and extent of the infarction measured by contrast-enhanced magnetic resonance imaging (Ce-MRI).
Echocardiography with TDI and Ce-MRI was performed within 6 days of acute MI in 47 patients and compared with 69 age-matched healthy volunteers. Regional myocardial velocities were assessed in 12 segments, and the corresponding systolic velocity (Sm), early diastolic velocity (Em), as well as the time to peak Sm (Ts) and time to peak Em (Te) were measured. To assess LV synchronicity, SDs of Ts (Ts-SD) and Te (Te-SD) of all 12 segments were computed. Location and size of infarct were confirmed by Ce-MRI with a 16-segment model.
All the patients had a normal QRS complex duration. The Ts-SD was significantly prolonged in the MI group when compared with controls (42.2 +/- 13.7 vs 18.0 +/- 7.0 milliseconds, P < .001). The Ts-SD was longer in patients with anterior than inferior MI (46.8 +/- 13.9 vs 34.6 +/- 8.5 milliseconds, P = .002). Stepwise multiple regression analysis revealed that infarct size was the main independent predictor of systolic asynchrony ( B = 0.79, 95% CI 0.75-1.23, P < .001). Asynchrony was not related to the transmurality of the infarction.
Myocardial infarction has a significant impact on LV synchronicity even in those with a narrow QRS complex. The degree of LV systolic asynchrony is mainly determined by the infarct size and not transmurality.
本研究旨在使用组织多普勒成像（TDI）评估QRS波群狭窄的心肌梗死（MI）患者左心室（LV）的不同步程度，并将其与通过对比增强磁共振成像（Ce-MRI）测量的梗死部位和范围相关联。
对47例急性心肌梗死患者在发病6天内进行了TDI超声心动图和Ce-MRI检查，并与69名年龄匹配的健康志愿者进行比较。在12个节段评估局部心肌速度，并测量相应的收缩期速度（Sm）、舒张早期速度（Em）以及Sm峰值时间（Ts）和Em峰值时间（Te）。为评估左心室同步性，计算所有12个节段的Ts标准差（Ts-SD）和Te标准差（Te-SD）。通过Ce-MRI的16节段模型确定梗死的位置和大小。
所有患者的QRS波群时限均正常。与对照组相比，MI组的Ts-SD显著延长（42.2±13.7对18.0±7.0毫秒，P<.001）。前壁心肌梗死患者的Ts-SD长于下壁心肌梗死患者（46.8±13.9对34.6±8.5毫秒，P=.002）。逐步多元回归分析显示，梗死面积是收缩期不同步的主要独立预测因素（B=0.79，95%CI 0.75-1.23，P<.001）。不同步与梗死的透壁性无关。
即使是QRS波群狭窄的患者，心肌梗死对左心室同步性也有显著影响。左心室收缩期不同步程度主要由梗死面积而非透壁性决定。
