Betensky Brian P, Dong Wei, D'Souza Benjamin A, Zado Erica S, Han Yuchi, Marchlinski Francis E
Cardiac Electrophysiology Section, Hospital of the University of Pennsylvania, 3400 Spruce Street, Founders 9, Philadelphia, PA, 19104, USA.
Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
J Interv Card Electrophysiol. 2017 Jun;49(1):11-19. doi: 10.1007/s10840-017-0228-8. Epub 2017 Feb 24.
Magnetic resonance imaging (MRI) with late gadolinium enhancement is commonly performed in patients with non-ischemic LV ventricular tachycardia/ventricular premature depolarizations (non-ischemic LV-VT/VPDs) to define VT substrate prior to catheter ablation. We investigated the prevalence of abnormal voltage and VT localized to areas of the myocardium not reported to have late gadolinium enhancement (LGE) on routine pre-procedural MRI and sought to determine if quantitative MRI analysis could reduce this discordance.
Patients with non-ischemic LV-VT/VPD who underwent LV endocardial mapping with VT/VPD ablation and either septal or free wall MRI-voltage discordance were studied. Electroanatomic maps were analyzed post-procedure for areas of electrogram-defined scar and VT localized to areas without reported LGE. Discordant segments were then analyzed offline using delayed signal intensity of >2 and >5 standard deviations above normal myocardium.
Of 90 consecutive patients, 32 (36%) patients with septal (n = 16), free wall (n = 14) or both (n = 2) MRI-voltage + mismatch were identified. All discordant segments demonstrated unipolar voltage abnormalities with 12 patients (6 septal and 6 free wall) also showing low bipolar voltage but no LGE at signal intensity >5 standard deviations. Eleven patients (5 septum, 6 free wall) had VT localized to discordant areas. Ninety-three percent of patients in the septal group (26/48 segments) and 89% of patients in the free wall group (9/13 segments) had a concordant response established by using a signal intensity cutoff of >2 standard deviations.
MRI-voltage discordance was identified in 36% of patients with non-ischemic LV-VT/VPD who underwent VT ablation. In 12% of patients, VT was targeted in areas of abnormal voltage not suggested by routine qualitative MRI. Quantitative MRI analysis using a lower signal intensity threshold increased the sensitivity for detecting areas of clinically relevant VT substrate.
对于非缺血性左心室室性心动过速/室性早搏（非缺血性左心室室速/室早）患者，通常在导管消融术前进行钆剂延迟增强磁共振成像（MRI）以明确室速基质。我们调查了在常规术前MRI上未报告有钆剂延迟增强（LGE）的心肌区域出现异常电压和室速的发生率，并试图确定定量MRI分析是否可以减少这种不一致性。
对接受左心室内膜标测及室速/室早消融且存在间隔或游离壁MRI电压不一致的非缺血性左心室室速/室早患者进行研究。术后分析电解剖图，以确定电信号定义的瘢痕区域以及位于未报告有LGE区域的室速。然后使用高于正常心肌2倍和5倍标准差的延迟信号强度对不一致节段进行离线分析。
在连续90例患者中，识别出32例（36%）存在间隔（n = 16）、游离壁（n = 14）或两者（n =？此处原文有误，推测可能是2）MRI电压+不匹配的患者。所有不一致节段均显示单极电压异常，12例患者（6例间隔和6例游离壁）还显示双极电压低，但在信号强度>5倍标准差时无LGE。11例患者（5例间隔，6例游离壁）的室速定位于不一致区域。间隔组93%的患者（26/48节段）和游离壁组89%的患者（9/13节段）通过使用>2倍标准差的信号强度截断值建立了一致反应。
在接受室速消融的非缺血性左心室室速/室早患者中，36%存在MRI电压不一致。在12%的患者中，室速靶点位于常规定性MRI未提示的异常电压区域。使用较低信号强度阈值的定量MRI分析提高了检测临床相关室速基质区域的敏感性。
