McLELLAN Alex J A, Ellims Andris H, Prabhu Sandeep, Voskoboinik Alex, Iles Leah M, Hare James L, Kaye David M, Macciocca Ivan, Mariani Justin A, Kalman Jonathan M, Taylor Andrew J, Kistler Peter M
Department of Cardiovascular Medicine, Alfred Hospital and Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
Cardiology Department, Royal Melbourne Hospital, Melbourne, Victoria, Australia.
J Cardiovasc Electrophysiol. 2016 May;27(5):571-80. doi: 10.1111/jce.12948. Epub 2016 Mar 14.
Non-sustained ventricular tachycardia (NSVT) is a risk factor for sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM). We aimed to assess whether diffuse ventricular fibrosis on cardiac magnetic resonance (CMR) imaging could be a surrogate marker for ventricular arrhythmias in patients with HCM.
A total of 100 patients with HCM (mean age 51 ± 13 years, septal wall thickness 20 ± 5 mm) underwent CMR with a 1.5 T scanner to determine the presence of ventricular late gadolinium enhancement (LGE) for focal fibrosis, and post-contrast T1 mapping for diffuse ventricular fibrosis. The presence of NSVT was determined by Holter monitoring and a subset of high risk patients received an implantable cardioverter-defibrillator (ICD).
NSVT was detected in 23 of 100 patients with HCM. Focal ventricular fibrosis (by LGE) was observed in 87%, with no significant difference between patients with (96%) or without NSVT (86%, P = 0.19). However, LGE mass was greater in patients with (16.5 ± 19.1 g) versus without NSVT (7.6 ± 10.2 g, P < 0.01). NSVT was associated with a significant reduction in ventricular T1 relaxation time (422 ± 54 milliseconds) versus patients without NSVT (512 ± 115 milliseconds; P < 0.001). There was significant reduction in ventricular T1 relaxation time in patients with (430 ± 48 milliseconds) versus without aborted SCD (495 ± 113 milliseconds; P = 0.01) over a mean follow-up of 40 ± 10 months. On multivariate analysis post-contrast ventricular T1 relaxation time and septal wall thickness were the only predictors of NSVT.
Post-contrast T1 relaxation time on CMR is associated with ventricular arrhythmias in patients with HCM. Diffuse ventricular fibrosis may be an important marker of arrhythmic risk in patients with HCM.
非持续性室性心动过速（NSVT）是肥厚型心肌病（HCM）患者心源性猝死（SCD）的危险因素。我们旨在评估心脏磁共振成像（CMR）上的弥漫性心室纤维化是否可作为HCM患者室性心律失常的替代标志物。
总共100例HCM患者（平均年龄51±13岁，室间隔厚度20±5mm）接受了1.5T扫描仪的CMR检查，以确定是否存在用于局灶性纤维化的心室晚期钆增强（LGE）以及用于弥漫性心室纤维化的对比剂后T1映射。通过动态心电图监测确定NSVT的存在，一部分高危患者接受了植入式心脏复律除颤器（ICD）。
100例HCM患者中有23例检测到NSVT。87%的患者观察到局灶性心室纤维化（通过LGE），有NSVT（96%）和无NSVT（86%）的患者之间无显著差异（P = 0.19）。然而，有NSVT的患者（16.5±19.1g）的LGE质量大于无NSVT的患者（7.6±10.2g，P < 0.01）。与无NSVT的患者（512±115毫秒）相比，NSVT与心室T1弛豫时间显著缩短（422±54毫秒）相关（P < 0.001）。在平均40±10个月的随访中，有（430±48毫秒）与无心脏骤停性SCD（495±113毫秒）的患者相比，心室T1弛豫时间显著缩短（P = 0.01）。多因素分析显示，对比剂后心室T1弛豫时间和室间隔厚度是NSVT的唯一预测因素。
CMR上对比剂后T1弛豫时间与HCM患者的室性心律失常相关。弥漫性心室纤维化可能是HCM患者心律失常风险的重要标志物。
