Heart Rhythm Center (M.C., A.G., R.S., V.C., M.B., G.V., C.T.), Centro Cardiologico Monzino IRCCS, Milano.
Cardiology and Arrhythmology Clinic, Department of Clinical, Special and Dental Sciences (M.C.), University Hospital "Umberto I-Lancisi-Salesi", Marche Polytechnic University, Ancona, Italy.
Circ Arrhythm Electrophysiol. 2020 Dec;13(12):e009005. doi: 10.1161/CIRCEP.120.009005. Epub 2020 Dec 15.
Arrhythmogenic left ventricular cardiomyopathy (ALVC) is an under-characterized phenotype of arrhythmogenic cardiomyopathy involving the LV ab initio. ALVC was not included in the 2010 International Task Force Criteria for arrhythmogenic right ventricular cardiomyopathy diagnosis and data regarding this phenotype are scarce.
Clinical characteristics were reported from all consecutive patients diagnosed with ALVC, defined as a LV isolated late gadolinium enhancement and fibro-fatty replacement at cardiac magnetic resonance plus genetic variants associated with arrhythmogenic right ventricular cardiomyopathy and of an endomyocardial biopsy showing fibro-fatty replacement complying with the 2010 International Task Force Criteria in the LV.
Twenty-five patients ALVC (53 [48-59] years, 60% male) were enrolled. T wave inversion in infero-lateral and left precordial leads were the most common ECG abnormalities. Overall arrhythmic burden at study inclusion was 56%. Cardiac magnetic resonance showed LV late gadolinium enhancement in the LV lateral and posterior basal segments in all patients. In 72% of the patients an invasive evaluation was performed, in which electroanatomical voltage mapping and electroanatomical voltage mapping-guided endomyocardial biopsy showed low endocardial voltages and fibro-fatty replacement in areas of late gadolinium enhancement presence. Genetic variants in desmosomal genes (desmoplakin and desmoglein-2) were identified in 12/25 of the cohort presenting pathogenic/likely pathogenic variants. A definite/borderline 2010 International Task Force Criteria arrhythmogenic right ventricular cardiomyopathy diagnosis was reached only in 11/25 patients.
ALVC presents with a preferential involvement of the lateral and postero-lateral basal LV and is associated mostly with variants in desmoplakin and desmoglein-2 genes. An amendment to the current International Task Force Criteria is reasonable to better diagnose patients with ALVC.
致心律失常性左心室心肌病（ALVC）是一种表现为左心室起始部位心律失常性心肌病的特征尚未完全明确的表型。ALVC 并未被纳入 2010 年国际心律失常性右心室心肌病工作组诊断标准，且关于该表型的数据非常有限。
我们报告了所有连续诊断为 ALVC 的患者的临床特征，其定义为左心室孤立性延迟钆增强和心脏磁共振显示纤维脂肪替代，以及伴有致心律失常性右心室心肌病的基因突变，并在左心室进行符合 2010 年国际心律失常性右心室心肌病工作组标准的心肌活检显示纤维脂肪替代。
共纳入 25 例 ALVC 患者（53 [48-59] 岁，60%为男性）。心电图异常最常见的是下壁和左侧心前区导联 T 波倒置。在研究纳入时，整体心律失常负荷为 56%。心脏磁共振显示所有患者的左心室外侧和后基底段有左心室延迟钆增强。在 72%的患者中进行了有创评估，其中电解剖电压图和电解剖电压图引导的心肌活检显示，在延迟钆增强存在的区域存在低心内膜电压和纤维脂肪替代。在该队列中，12/25 名患者存在桥粒蛋白基因（桥粒斑蛋白和桥粒芯糖蛋白 2）的致病性/可能致病性变异。仅 11/25 名患者达到明确/边界 2010 年国际心律失常性右心室心肌病工作组诊断标准。
ALVC 主要表现为左心室外侧和后外侧基底段的优先受累，且主要与桥粒斑蛋白和桥粒芯糖蛋白 2 基因的变异相关。对当前国际心律失常性右心室心肌病工作组标准进行修正以更好地诊断 ALVC 患者是合理的。
