Left ventricular (LV) fibrofatty infiltration in arrhythmogenic right ventricular (RV) dysplasia/cardiomyopathy (ARVD/C) has been reported, however, detailed cardiovascular magnetic resonance (CMR) characteristics and association with outcomes are uncertain. We aim to describe LV findings on CMR in ARVD/C patients and their relationship with arrhythmic outcomes. CMR of 73 subjects with ARVD/C according to the 2010 Task Force Criteria (TFC) were analyzed for LV involvement, defined as ≥ 1 of the following features: LV wall motion abnormality, LV late gadolinium enhancement (LGE), LV fat infiltration, or LV ejection fraction (LVEF) < 50%. Ventricular volumes and function, regional wall motion abnormalities, and the presence of ventricular fat or fibrosis were recorded. Findings on CMR were correlated with arrhythmic outcomes. Of the 73 subjects, 50.7% had CMR evidence for LV involvement. Proband status and advanced RV dysfunction were independently associated with LV abnormalities. The most common pattern of LV involvement was focal fatty infiltration in the sub-epicardium of the apicolateral LV with a “bite-like” pattern. LGE in the LV was found in the same distribution and most often had a linear appearance. LV involvement was more common with non-PKP2 genetic mutation variants, regardless of proband status. Only RV structural disease on CMR (HR 3.47, 95% CI 1.13–10.70) and prior arrhythmia (HR 2.85, 95% CI 1.33–6.10) were independently associated with arrhythmic events. Among patients with 2010 TFC for ARVD/C, CMR evidence for LV abnormalities are seen in half of patients and typically manifest as fibrofatty infiltration in the subepicardium of the apicolateral wall and are not associated with arrhythmic outcomes.

中文翻译：

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左心室纤维脂肪替代治疗致心律失常性右心室发育不良/心肌病：患病率、模式以及与心律失常的关联


致心律失常性右心室 (RV) 发育不良/心肌病 (ARVD/C) 中的左心室 (LV) 纤维脂肪浸润已有报道，然而，详细的心血管磁共振 (CMR) 特征以及与结果的关联尚不确定。我们的目的是描述 ARVD/C 患者 CMR 的 LV 结果及其与心律失常结果的关系。根据 2010 年工作组标准 (TFC)，对 73 名 ARVD/C 受试者的 CMR 进行了左室受累分析，定义为以下特征中≥ 1 项：左室壁运动异常、左室晚期钆增强 (LGE)、左室脂肪浸润、或 LV 射血分数 (LVEF) < 50%。记录心室体积和功能、局部室壁运动异常以及心室脂肪或纤维化的存在。 CMR 的结果与心律失常结果相关。在 73 名受试者中，50.7% 有左心室受累的 CMR 证据。先证者状态和晚期右心室功能障碍与左心室异常独立相关。左心室受累最常见的模式是左心室心外膜下局灶性脂肪浸润，呈“咬状”模式。 LV 中的 LGE 具有相同的分布，并且通常呈线性外观。无论先证者状态如何，左心室受累在非 PKP2 基因突变变异中更为常见。只有 CMR 上的右心室结构性疾病（HR 3.47，95% CI 1.13–10.70）和既往心律失常（HR 2.85，95% CI 1.33–6.10）与心律失常事件独立相关。在 2010 年因 ARVD/C 导致 TFC 的患者中，半数患者可见 CMR 左室异常的证据，通常表现为心外膜心外膜下纤维脂肪浸润，与心律失常结果无关。