Jackson Nicholas, Gizurarson Sigfus, Viswanathan Karthik, King Benjamin, Massé Stephane, Kusha Marjan, Porta-Sanchez Andreu, Jacob John Roshan, Khan Fakhar, Das Moloy, Ha Andrew C T, Pashaei Ali, Vigmond Edward, Downar Eugene, Nanthakumar Kumaraswamy
From the Toronto General Hospital, Toronto, Ontario, Canada (N.J., S.G., K.V., B.K., S.M., M.K., A.P.-S., J.R.J., F.K., M.D., A.C.T.H., E.D., K.N.); Laboratory IMB, University of Bordeaux, Talence, France (A.P., E.V.); and LIRYC Cardiac Electrophysiology and Heart Modelling Institute, University of Bordeaux Foundation, Pessac, France (A.P., E.V.).
Circ Arrhythm Electrophysiol. 2015 Dec;8(6):1433-42. doi: 10.1161/CIRCEP.115.003083. Epub 2015 Oct 19.
Substrate-based mapping for ventricular tachycardia (VT) ablation is hampered by its inability to determine critical sites of the VT circuit. We hypothesized that those potentials, which delay with a decremental extrastimulus (decrement evoked potentials or DEEPs), are more likely to colocalize with the diastolic pathways of VT circuits.
DEEPs were identified in intraoperative left ventricular maps from 6 patients with ischemic cardiomyopathy (total 9 VTs) and were compared with late potential (LP) and activation maps of the diastolic pathway for each VT. Mathematical modeling was also used to further validate and elucidate the mechanisms of DEEP mapping. All patients demonstrated regions of DEEPs and LPs. The mean endocardial surface area of these potentials was 18±4% and 21±6%, respectively (P=0.13). The mean sensitivity for identifying the diastolic pathway in VT was 50±23% for DEEPs and 36±32% for LPs (P=0.31). The mean specificity was 43±23% versus 20±8% for DEEP and LP mapping, respectively (P=0.031). The electrograms that displayed the greatest decrement in each case had a sensitivity and specificity for the VT isthmus of 29±10% and 95±1%, respectively. Mathematical modeling studies recapitulated DEEPs at the VT isthmus and demonstrated their role in VT initiation with a critical degree of decrement.
In this preliminary study, DEEP mapping was more specific than LP mapping for identifying the critical targets of VT ablation. The mechanism of DEEPs relates to conduction velocity restitution magnified by zigzag conduction within scar channels.
基于基质的室性心动过速（VT）消融标测因无法确定VT环路的关键部位而受到阻碍。我们推测，那些随递减期外刺激而延迟的电位（递减诱发电位或DEEPs）更有可能与VT环路的舒张期径路共定位。
在6例缺血性心肌病患者（共9次VT）的术中左心室标测图中识别出DEEPs，并将其与每次VT的舒张期径路的晚电位（LP）和激动标测图进行比较。还使用数学模型进一步验证和阐明DEEP标测的机制。所有患者均显示有DEEPs和LPs区域。这些电位的平均心内膜表面积分别为18±4%和21±6%（P = 0.13）。DEEPs识别VT舒张期径路的平均敏感性为50±23%，LPs为36±32%（P = 0.31）。DEEP和LP标测的平均特异性分别为43±23%和20±8%（P = 0.031）。在每种情况下显示最大递减的心电图对VT峡部的敏感性和特异性分别为29±10%和95±1%。数学模型研究在VT峡部再现了DEEPs，并证明了它们在具有关键递减程度的VT起始中的作用。
在这项初步研究中，DEEP标测在识别VT消融的关键靶点方面比LP标测更具特异性。DEEPs的机制与瘢痕通道内曲折传导放大的传导速度恢复有关。
