Department of Cardiology I, University Hospital Muenster, Münster, Germany.
Division of Cardiology, Robert-Bosch-Hospital, Stuttgart, Germany.
Clin Res Cardiol. 2019 Aug;108(8):857-867. doi: 10.1007/s00392-019-01414-0. Epub 2019 Feb 14.
Cardiac involvement in myotonic dystrophy type 1 (MD1) includes conduction disease, arrhythmias, and left-ventricular (LV) systolic dysfunction leading to an increased sudden cardiac death risk. An understanding of the interplay between electrical and structural myocardial changes could improve the prediction of adverse cardiac events. We aimed to explore the relationship between signs of cardiomyopathy by conventional and advanced cardiovascular magnetic resonance (CMR), and electrical abnormalities in MD1.
Fifty-seven MD1 patients (43 ± 13 years, 46% male) and 15 matched controls (41 ± 7 years, 53% male) underwent CMR including cine-imaging with feature-tracking strain analysis, late gadolinium enhancement (LGE), and native/post-contrast T1-mapping with extracellular volume calculation. Standard 12-lead and long-term ECG monitoring were performed as screening for rhythm and/or conduction abnormalities.
Abnormal ECGs were recorded in 40% of MD1; a pathologic CMR was found in 44%: 21% had an impaired LV-EF and 32% showed non-ischemic LGE. When looking at MD1 patients with available long-term ECG monitoring (n = 39), those with atrial fibrillation (Afib)/flutter(Afl) episodes had lower LV-EF (52 ± 7 vs. 60 ± 5%, p = 0.002), lower global longitudinal strain (- 17 ± 3 vs. - 20 ± 3%, p = 0.034), a trend to lower left atrial emptying fraction (LA-EF) (44 ± 14 vs. 55 ± 8%, p = 0.08), and higher prevalence of LGE (88% vs. 23%, p = 0.001) with an intramural (75% vs. 23%, p = 0.01) and septal (63% vs. 13%, p = 0.009) pattern. In a model including LV-EF (OR 0.8, 95% CI 0.7-1.0, p = NS) and LGE presence (OR 14.8, 95% CI 1.4-159.0, p = 0.026), only LGE was independently associated with the occurrence of Afib/Afl episodes.
Myocardial abnormalities depicted by non-ischemic LGE-CMR were the only independent predictor for the occurrence of Afib/Afl on ECG monitoring, previously shown to predict adverse cardiac events in MD1.
1 型肌强直性营养不良（MD1）的心脏受累包括传导疾病、心律失常和左心室（LV）收缩功能障碍，导致心脏性猝死风险增加。了解电和结构心肌变化之间的相互作用可以提高对不良心脏事件的预测。我们旨在探讨 MD1 中常规和先进心血管磁共振（CMR）检查所示的心肌病征象与电异常之间的关系。
57 例 MD1 患者（43±13 岁，46%为男性）和 15 名匹配的对照组（41±7 岁，53%为男性）接受 CMR 检查，包括电影成像与特征追踪应变分析、晚期钆增强（LGE）以及细胞外容积计算的原生/对比 T1 映射。标准 12 导联心电图和长期心电图监测用于筛查心律失常和/或传导异常。
40%的 MD1 患者记录到异常心电图；44%的患者出现异常 CMR：21%的患者左心室射血分数（EF）受损，32%的患者出现非缺血性 LGE。在观察到有长期心电图监测的 MD1 患者（n=39）中，有房颤/房扑（Afib/Afl）发作的患者左心室 EF 较低（52±7%比 60±5%，p=0.002），整体纵向应变较低（-17±3%比-20±3%，p=0.034），左心房排空分数（LA-EF）较低（44±14%比 55±8%，p=0.08），LGE 更常见（88%比 23%，p=0.001），并且具有壁内（75%比 23%，p=0.01）和间隔（63%比 13%，p=0.009）模式。在包括左心室 EF（OR 0.8，95%CI 0.7-1.0，p=NS）和 LGE 存在（OR 14.8，95%CI 1.4-159.0，p=0.026）的模型中，只有 LGE 是 Afib/Afl 发作的独立预测因素。
CMR 显示的非缺血性 LGE 心肌异常是心电图监测中 Afib/Afl 发生的唯一独立预测因素，此前已证明其可预测 MD1 中的不良心脏事件。
