Njeim Mario, Yokokawa Miki, Frank Luba, Crawford Thomas, Good Eric, Morady Fred, Bogun Frank
Division of Cardiovascular Medicine and the Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA.
J Cardiovasc Electrophysiol. 2016 Feb;27(2):183-9. doi: 10.1111/jce.12848. Epub 2015 Nov 6.
Ventricular tachycardia (VT) in patients with cardiomyopathy originates in scar tissue. Intramural or epicardial scar may result in ineffective ablation if mapping and ablation are limited to the endocardium. The purpose of this study was to investigate whether preprocedural magnetic resonance imaging (MRI) is beneficial in patients with failed endocardial VT ablations in determining an appropriate ablation strategy.
A cardiac MRI was performed in 20 patients with a failed ablation procedure and cardiomyopathy (nonischemic n = 12, ischemic n = 8). A subsequent ablation strategy was determined by a delayed enhanced MRI (DE-MRI) and an epicardial subxyphoid access was planned only in patients with epicardial or intramural free-wall scar. MRIs were performed in all patients with or without an implanted cardioverter defibrillator (ICD). The location of scar tissue in the MRI predicted the origin of VT in all patients. In 9/20 patients an epicardial procedure was performed based on the result of the MRI. An endocardial procedure was performed in the remaining 11 patients who had either endocardial or septal scarring and one patient in whom the MRI only showed artifact. Five patients remained inducible postablation and four patients had VT recurrence within a follow-up period of 17 ± 22 months. All of the latter patients had an intramural scar pattern.
Imaging with DE-MRI prior to VT ablation in patients with previously failed endocardial ablation procedures is beneficial in identifying an ablation strategy, helps to focus on an area of interest intraprocedurally, and provides valuable outcomes information.
心肌病患者的室性心动过速（VT）起源于瘢痕组织。如果标测和消融仅限于心内膜，壁内或心外膜瘢痕可能导致消融无效。本研究的目的是调查术前磁共振成像（MRI）对心内膜VT消融失败的患者确定合适的消融策略是否有益。
对20例消融手术失败且患有心肌病的患者（非缺血性12例，缺血性8例）进行了心脏MRI检查。随后通过延迟强化MRI（DE-MRI）确定消融策略，仅对有心外膜或壁内游离壁瘢痕的患者计划经剑突下心外膜入路。所有患者无论是否植入心脏复律除颤器（ICD）均进行了MRI检查。MRI中瘢痕组织的位置在所有患者中都可预测VT的起源。根据MRI结果，9/20例患者进行了心外膜手术。其余11例有心内膜或间隔瘢痕的患者以及1例MRI仅显示伪影的患者进行了心内膜手术。5例患者消融后仍可诱发VT，4例患者在17±22个月的随访期内出现VT复发。所有后一组患者均有壁内瘢痕模式。
对于先前心内膜消融手术失败的患者，在VT消融术前进行DE-MRI成像有助于确定消融策略，有助于在手术过程中聚焦感兴趣区域，并提供有价值的预后信息。
