AIMS  Myocardial scar detected by cardiovascular magnetic resonance has been associated with sudden cardiac death in dilated cardiomyopathy (DCM). Certain genetic causes of DCM may cause a malignant arrhythmogenic phenotype. The concepts of arrhythmogenic left ventricular (LV) cardiomyopathy (ALVC) and arrhythmogenic DCM are currently ill-defined. We hypothesized that a distinctive imaging phenotype defines ALVC. METHODS AND RESULTS  Eighty-nine patients with DCM-associated mutations [desmoplakin (DSP) n = 25, filamin C (FLNC) n = 7, titin n = 30, lamin A/C n = 12, bcl2-associated athanogene 3 n = 3, RNA binding motif protein 20 n = 3, cardiac sodium channel NAv1.5 n = 2, and sarcomeric genes n = 7] were comprehensively phenotyped. Clustering analysis resulted in two groups: 'DSP/FLNC genotypes' and 'non-DSP/FLNC'. There were no significant differences in age, sex, symptoms, baseline electrocardiography, arrhythmia burden, or ventricular volumes between the two groups. Subepicardial LV late gadolinium enhancement with ring-like pattern (at least three contiguous segments in the same short-axis slice) was observed in 78.1% of DSP/FLNC genotypes but was absent in the other DCM genotypes (P < 0.001). Left ventricular ejection fraction (LVEF) and global longitudinal strain were lower in other DCM genotypes (P = 0.053 and P = 0.015, respectively), but LV regional wall motion abnormalities were more common in DSP/FLNC genotypes (P < 0.001). DSP/FLNC patients with non-sustained ventricular tachycardia (NSVT) had more LV scar (P = 0.010), whereas other DCM genotypes patients with NSVT had lower LVEF (P = 0.001) than patients without NSVT. CONCLUSION DSP/FLNC genotypes cause more regionality in LV impairment. The most defining characteristic is a subepicardial ring-like scar pattern in DSP/FLNC, which should be considered in future diagnostic criteria for ALVC.

中文翻译：

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扩张型心肌病和致心律失常性左心室心肌病：综合基因型成像表型研究。

AIMS 通过心血管磁共振检测到的心肌瘢痕与扩张型心肌病 (DCM) 中的心源性猝死有关。DCM 的某些遗传原因可能导致恶性心律失常表型。致心律失常左心室 (LV) 心肌病 (ALVC) 和致心律失常 DCM 的概念目前尚不明确。我们假设独特的成像表型定义了 ALVC。方法和结果 89 名患有 DCM 相关突变的患者 [desmoplakin (DSP) n = 25，细丝蛋白 C (FLNC) n = 7，titin n = 30，lamin A/C n = 12，bcl2 相关的 athanogene 3 n = 3、对RNA结合基序蛋白20 n = 3、心脏钠通道NAv1.5 n = 2、肌节基因n = 7]进行了全面的表型分析。聚类分析产生两组：“DSP/FLNC 基因型”和“非 DSP/FLNC”。两组在年龄、性别、症状、基线心电图、心律失常负担或心室容积方面没有显着差异。在 78.1% 的 DSP/FLNC 基因型中观察到心外膜下 LV 晚期钆增强伴环状图案（在同一短轴切片中至少三个连续节段），但在其他 DCM 基因型中不存在（P < 0.001）。左心室射血分数 (LVEF) 和整体纵向应变在其他 DCM 基因型中较低（分别为 P = 0.053 和 P = 0.015），但在 DSP/FLNC 基因型中，LV 局部室壁运动异常更常见（P < 0.001）。非持续性室性心动过速 (NSVT) 的 DSP/FLNC 患者的 LV 瘢痕较多 (P = 0.010)，而其他 DCM 基因型的 NSVT 患者的 LVEF (P = 0.001) 低于没有 NSVT 的患者。结论 DSP/FLNC 基因型在 LV 损伤中引起更多的区域性。最明确的特征是 DSP/FLNC 的心外膜下环状瘢痕模式，应在未来的 ALVC 诊断标准中考虑。