van Dijk J, Knaapen P, Russel I K, Hendriks T, Allaart C P, de Cock C C, Kamp O
Department of Cardiology, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
Europace. 2008 Jan;10(1):63-8. doi: 10.1093/europace/eum262. Epub 2007 Dec 7.
One-third of dilated cardiomyopathy patients receiving a biventricular pacing-device do not respond to this form of therapy. Therefore, the utility of mechanical dyssynchrony by real-time 3D echocardiography (RT3DE) for predicting systolic response to biventricular pacing, of which maximal rate of pressure rise (dP/dt(max)) served as the gold-standard, was evaluated.
Seventeen consecutive heart failure patients (aged 64 +/- 10 years, 8 male, 6 ischaemic cardiomyopathy, mean QRS duration 136 +/- 32 ms) underwent RT3DE and biventricular pacing. Post-processing software provided data of global left ventricular (LV) function and the systolic dyssynchrony index of 17 LV segments (SDI(17), %) for mechanical dyssynchrony. During biventricular pacing, percentual change in dP/dt(max) compared to the non-pacing mode, DeltadP/dt(max) was measured invasively with conductance catheters. LV ejection fraction was 31 +/- 10%, SDI(17) was 10.2 +/- 4.2% and percentual DeltadP/dt(max) during biventricular pacing was 14.5 +/- 12.4. A significant correlation (r = 0.729, P = 0.001) was found between SDI(17) and percentual DeltadP/dt(max), and between QRS duration and percentual DeltadP/dt(max) (r = 0.721, P = 0.001).
The present study suggests that mechanical dyssynchrony measured by RT3DE shows a good correlation with invasively determined acute haemodynamic response to biventricular pacing in patients with symptomatic dilated cardiomyopathy. Future studies are needed to further define the clinical utility of RT3DE in identifying patients who are most likely to respond to cardiac resynchronization therapy.
接受双心室起搏装置治疗的扩张型心肌病患者中有三分之一对这种治疗方式无反应。因此，评估了实时三维超声心动图（RT3DE）测量的机械性不同步对于预测双心室起搏收缩反应的效用，其中最大压力上升速率（dP/dt(max)）作为金标准。
17例连续的心力衰竭患者（年龄64±10岁，男性8例，缺血性心肌病6例，平均QRS时限136±32毫秒）接受了RT3DE检查和双心室起搏。后处理软件提供了整体左心室（LV）功能数据以及用于评估机械性不同步的17个左心室节段的收缩不同步指数（SDI(17)，%）。在双心室起搏期间，使用电导导管有创测量与非起搏模式相比dP/dt(max)的百分比变化，即ΔdP/dt(max)。左心室射血分数为31±10%，SDI(17)为10.2±4.2%，双心室起搏期间ΔdP/dt(max)的百分比为14.5±12.4。发现SDI(17)与ΔdP/dt(max)百分比之间以及QRS时限与ΔdP/dt(max)百分比之间存在显著相关性（r = 0.729，P = 0.001；r = 0.721，P = 0.001）。
本研究表明，RT3DE测量的机械性不同步与有症状扩张型心肌病患者经有创测定的双心室起搏急性血流动力学反应具有良好相关性。需要进一步的研究来进一步明确RT3DE在识别最可能对心脏再同步治疗有反应的患者中的临床效用。
