Fukumoto Kotaro, Habibi Mohammadali, Ipek Esra Gucuk, Zahid Sohail, Khurram Irfan M, Zimmerman Stefan L, Zipunnikov Vadim, Spragg David, Ashikaga Hiroshi, Trayanova Natalia, Tomaselli Gordon F, Rickard John, Marine Joseph E, Berger Ronald D, Calkins Hugh, Nazarian Saman
From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
Circ Arrhythm Electrophysiol. 2016 Mar;9(3):e002897. doi: 10.1161/CIRCEP.115.002897.
Prior studies have demonstrated regional left atrial late gadolinium enhancement (LGE) heterogeneity on magnetic resonance imaging. Heterogeneity in regional conduction velocities is a critical substrate for functional reentry. We sought to examine the association between left atrial conduction velocity and LGE in patients with atrial fibrillation.
LGE imaging and left atrial activation mapping were performed during sinus rhythm in 22 patients before pulmonary vein isolation. The locations of 1468 electroanatomic map points were registered to the corresponding anatomic sites on 469 axial LGE image planes. The local conduction velocity at each point was calculated using previously established methods. The myocardial wall thickness and image intensity ratio defined as left atrial myocardial LGE signal intensity divided by the mean left atrial blood pool intensity was calculated for each mapping site. The local conduction velocity and image intensity ratio in the left atrium (mean ± SD) were 0.98 ± 0.46 and 0.95 ± 0.26 m/s, respectively. In multivariable regression analysis, clustered by patient, and adjusting for left atrial wall thickness, conduction velocity was associated with the local image intensity ratio (0.20 m/s decrease in conduction velocity per increase in unit image intensity ratio, P<0.001).
In this clinical in vivo study, we demonstrate that left atrial myocardium with increased gadolinium uptake has lower local conduction velocity. Identification of such regions may facilitate the targeting of the substrate for reentrant arrhythmias.
既往研究已证实在磁共振成像上存在左心房晚期钆增强（LGE）区域异质性。区域传导速度的异质性是功能性折返的关键基础。我们试图研究心房颤动患者左心房传导速度与LGE之间的关联。
在22例患者肺静脉隔离术前窦性心律期间进行LGE成像和左心房激动标测。将1468个电解剖标测点的位置与469个轴向LGE图像平面上的相应解剖部位进行配准。使用先前建立的方法计算每个点的局部传导速度。计算每个标测部位的心肌壁厚度和图像强度比，定义为左心房心肌LGE信号强度除以左心房平均血池强度。左心房的局部传导速度和图像强度比（均值±标准差）分别为0.98±0.46和0.95±0.26m/s。在多变量回归分析中，以患者为聚类，并校正左心房壁厚度，传导速度与局部图像强度比相关（单位图像强度比每增加，传导速度降低0.20m/s，P<0.001）。
在这项临床体内研究中，我们证明钆摄取增加的左心房心肌局部传导速度较低。识别这些区域可能有助于确定折返性心律失常的基质靶点。
