Dixit Sanjay, Callans David J
Section of Cardiac Electrophysiology, Hospital of The University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Card Electrophysiol Rev. 2002 Dec;6(4):436-41. doi: 10.1023/a:1021196627551.
Mapping strategies for ventricular tachycardia (VT) have evolved significantly in the past 2 decades. This review discusses mapping techniques that can help in successful VT ablation. The electrocardiogram (ECG) remains a vital component of VT mapping and can help to identify the chamber of origin of VT. The ECG morphology of VT, however, is influenced by orientation of heart and location of the scar. Activation mapping during VT is an important technique that can help in further localization. Care has to be exercised to ensure that small signals are not ignored and far-field signals are recognized. Pace-mapping to mimic the VT is another way to map exit site for scar based reentrant VT or the site of origin of triggered and automatic VT in the absence of structural heart disease. For the latter group, this technique is widely used in determining the site of ablation. It is important to ensure a complete ECG match (12 out of 12 leads) of the pace-map to the clinical arrhythmia in these patients. In patients with structural heart disease, entrainment mapping remains the gold standard for defining the protected isthmus and other components of the VT circuit. Using this technique, successful ablation of reentrant VT can be achieved in 60-90% of patients. In order to perform entrainment mapping, the VT has to be hemodynamically tolerated; this is not the case in 25% of pts with scar based reentrant VT. The development of 3-dimensional mapping systems allows for more anatomically based linear ablation in patients with poorly tolerated uniform VT. Despite these advances, there are still about 10-20% VTs that cannot be ablated successfully with the above described techniques, especially in patients with structural heart disease. Other recent advances such as percutaneous closed chest epicardial mapping technique and cooled tip ablation catheter technology have the potential to enhance mapping and successful ablation of VT.
在过去20年里，室性心动过速（VT）的标测策略有了显著发展。本综述讨论了有助于成功进行VT消融的标测技术。心电图（ECG）仍然是VT标测的重要组成部分，有助于确定VT的起源部位。然而，VT的心电图形态受心脏方向和瘢痕位置的影响。VT发作时的激动标测是一项重要技术，有助于进一步定位。必须注意确保不忽略小信号并识别远场信号。起搏标测以模拟VT是另一种标测基于瘢痕的折返性VT的出口部位或无结构性心脏病时触发和自律性VT起源部位的方法。对于后一组患者，该技术广泛用于确定消融部位。确保这些患者的起搏心电图与临床心律失常在12导联中完全匹配（12/12导联）很重要。在患有结构性心脏病的患者中，拖带标测仍然是定义VT折返环的受保护峡部和其他组成部分的金标准。使用该技术，60% - 90%的患者可成功消融折返性VT。为了进行拖带标测，VT必须在血流动力学上能够耐受；25%基于瘢痕的折返性VT患者并非如此。三维标测系统的发展使得在耐受性差的均匀VT患者中能够进行更多基于解剖结构的线性消融。尽管有这些进展，仍有大约10% - 20%的VT不能通过上述技术成功消融，特别是在患有结构性心脏病的患者中。其他近期进展，如经皮闭式心外膜标测技术和冷端消融导管技术，有可能增强VT的标测和成功消融。
