Silva Jennifer N A, Ghosh Subham, Bowman Tammy M, Rhee Edward K, Woodard Pamela K, Rudy Yoram
Division of Pediatric Cardiology, Washington University School of Medicine/St Louis Children's Hospital, Washington University, St Louis, Missouri 63130-4899, USA.
Heart Rhythm. 2009 Aug;6(8):1178-85. doi: 10.1016/j.hrthm.2009.04.017. Epub 2009 Apr 15.
Electrocardiographic imaging (ECGI) is a novel electrophysiologic imaging modality that may help guide patient selection and lead placement for cardiac resynchronization therapy (CRT).
The purpose of this study was to apply noninvasive ECGI to pediatric heart failure patients with congenital heart disease (CHD) undergoing evaluation for CRT.
ECGI was applied in eight patients with CHD who were either being evaluated for CRT or undergoing CRT. An electrical dyssynchrony (ED) index was computed from the ECGI epicardial activation maps as the standard deviation of activation times at 500 epicardial sites of the systemic ventricle. A normal ED of 20 +/- 4 ms was calculated from a control group of normal pediatric patients.
Four patients had an ECGI assessment for ED but did not undergo CRT implant. Two other patients had ECGI assessment pre-CRT that demonstrated abnormal ED and went on to CRT implant. In both cases, the resynchronization lead was placed at the site of latest electrical activation (as determined by ECGI) in pre-CRT baseline rhythm. A total of four patients (two responders, two nonresponders) were studied with post-CRT in multiple rhythms. Responders had an average ED of 22 ms in optimal CRT conditions. The nonresponder had very elevated ED (37 ms) in all rhythms including optimal CRT settings. ED and ECG QRS duration showed weak correlation (r = 0.58).
ECGI can be used in pediatric heart failure patients to evaluate ventricular ED and identify suitable candidates for CRT. In addition, ECGI can guide resynchronization lead placement to the area of latest electrical activation. It could also be used in noninvasive follow-ups for assessing synchrony and the electrophysiological substrate over time.
心电图成像（ECGI）是一种新型的电生理成像方式，可能有助于指导心脏再同步治疗（CRT）的患者选择和导线植入。
本研究的目的是将无创ECGI应用于接受CRT评估的先天性心脏病（CHD）小儿心力衰竭患者。
对8例接受CRT评估或正在接受CRT治疗的CHD患者应用ECGI。从ECGI心外膜激活图计算电不同步（ED）指数，作为体循环心室500个心外膜部位激活时间的标准差。从正常小儿患者对照组计算出正常ED为20±4毫秒。
4例患者进行了ED的ECGI评估，但未接受CRT植入。另外2例患者在CRT植入前进行了ECGI评估，结果显示ED异常，随后接受了CRT植入。在这两种情况下，再同步导线均放置在CRT植入前基线心律中电激活最晚的部位（由ECGI确定）。共有4例患者（2例反应者，2例无反应者）在多种心律下进行了CRT后研究。反应者在最佳CRT条件下的平均ED为22毫秒。无反应者在包括最佳CRT设置在内的所有心律中ED都非常高（37毫秒）。ED与心电图QRS波时限呈弱相关（r = 0.58）。
ECGI可用于小儿心力衰竭患者评估心室ED并识别适合CRT的患者。此外，ECGI可将再同步导线放置引导至电激活最晚的区域。它还可用于无创随访，以随时间评估同步性和电生理基质。
