Department of Cardiology, Oslo University Hospital, Rikshospitalet, , Oslo, Norway.
Heart. 2014 Apr;100(8):631-8. doi: 10.1136/heartjnl-2013-304923. Epub 2013 Dec 24.
Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging is the reference standard for non-invasive assessment of fibrosis. In hypertrophic cardiomyopathy (HCM) patients the histological substrate for LGE is still unknown. The aim of this study was to assess the ability of LGE and strain echocardiography to detect type and extent of myocardial fibrosis in obstructive HCM patients undergoing septal myectomy.
Thirty-two HCM patients (age 60±10) were included in this cross-sectional study and preoperatively examined by speckle-tracking strain echocardiography and LGE-CMR (n=21). Histological fibrosis was classified as interstitial, replacement and total.
Histological fibrosis was present in 31 patients. The percentage of total, interstitial and replacement fibrosis was 15(7, 31)%, 11(5, 24)% and 3(1, 6)%, respectively. Reduced longitudinal septal strain correlated with total (r=0.50, p=0.01) and interstitial (r=0.40, p=0.03), but not with replacement fibrosis (r=0.28, p=0.14). Septal LGE was detected in 13/21 (62%), but percentage LGE did not correlate with total fibrosis (r=0.25, p=0.28). Extent of fibrosis did not differ between patients with and without septal LGE (20(9, 58)% versus 14(5, 19)% p=0.41). Patients with ventricular arrhythmias (n=8) had lower septal longitudinal strain and increased extent total and interstitial fibrosis in myectomy specimens, but no differences were demonstrated in LGE. Reduced longitudinal septal strain and increased extent of interstitial fibrosis predicted ventricular arrhythmias independently of age and gender.
In myectomised HCM patients, reduced longitudinal septal strain correlated better with interstitial and total fibrosis in myectomy specimens, and was a more powerful tool to predict arrhythmias than LGE.
钆延迟增强心脏磁共振（LGE-CMR）成像技术是评估纤维化的非侵入性参考标准。在肥厚型心肌病（HCM）患者中，LGE 的组织学基础仍不清楚。本研究旨在评估 LGE 和应变超声心动图在检测接受室间隔心肌切除术的梗阻性 HCM 患者的心肌纤维化类型和程度方面的能力。
本研究共纳入 32 名 HCM 患者（年龄 60±10 岁），为横断面研究，术前均进行斑点追踪应变超声心动图和 LGE-CMR 检查（n=21）。将组织学纤维化分为间质型、替代型和总型。
31 名患者存在组织学纤维化。总纤维化、间质纤维化和替代纤维化的百分比分别为 15（7，31）%、11（5，24）%和 3（1，6）%。纵向室间隔应变降低与总纤维化（r=0.50，p=0.01）和间质纤维化（r=0.40，p=0.03）相关，但与替代纤维化无关（r=0.28，p=0.14）。21 名患者中的 13 名（62%）检测到室间隔 LGE，但 LGE 百分比与总纤维化无相关性（r=0.25，p=0.28）。有室间隔 LGE 和无室间隔 LGE 的患者纤维化程度无差异（20（9，58）%与 14（5，19）%，p=0.41）。8 名发生室性心律失常的患者的室间隔纵向应变降低，且心肌切除术标本中的总纤维化和间质纤维化程度增加，但 LGE 无差异。纵向室间隔应变降低和间质纤维化程度增加独立于年龄和性别预测心律失常。
在接受心肌切除术的 HCM 患者中，纵向室间隔应变与心肌切除术标本中的间质纤维化和总纤维化相关性更好，且预测心律失常的能力优于 LGE。
