Tran Van Nam, Rotman Samuel, Carroz Patrice, Pruvot Etienne
Department of Heart and Vessel, Service of Cardiology, University Hospital of Lausanne (CHUV), Rue du Bugnon 46, CH-1011 Lausanne, Switzerland.
Department for Laboratory Medicine and Pathology, Service of Pathology, Hospital of Lausanne and University of Lausanne, Rue du Bugnon 21, 1011 Lausanne, Switzerland.
Eur Heart J Case Rep. 2020 Dec 2;4(6):1-7. doi: 10.1093/ehjcr/ytaa434. eCollection 2020 Dec.
We report an unusual case of non-sustained ventricular tachycardia (NSVT) from the epicardial part of the right ventricular outflow tract (RVOT).
A 37-year-old woman who underwent in 2006 an ablation for idiopathic ventricular premature beats (VPBs) from the RVOT presented with pre-syncopal NSVT in 2016. A cardiac workup showed no coronary disease, normal biventricular function, and no enhancement on cardiac magnetic resonance imaging. A metabolic positron emission tomography scan excluded inflammation. Biopsies revealed normal desmosomal proteins. An endocardial mapping revealed an area of low voltage potential (<0.5 mV) at the antero-septal aspect of the RVOT corresponding to the initial site of ablation from 2006. Activation mapping revealed poor prematurity and pace-mapping showed unsatisfactory morphologies in the RVOT, the left ventricle outflow tract and the right coronary cusp. An epicardial map revealed a low voltage area at the antero-septal aspect of the RVOT with fragmented potentials opposite to the endocardial scar. Pace-mapping demonstrated perfect match. An NSVT was induced and local electrocardiogram showed mid-diastolic potentials. Ablation was applied epicardially and endocardially without any complication. The patient was arrhythmia free at 4-year follow-up.
Cardiac workup allowed to exclude specific conditions such as arrhythmogenic cardiomyopathy, tetralogy of Fallot, sarcoidosis, or myocarditis as a cause for NSVT from the RVOT. The epi and endocardial map showed residual scar subsequent to the first ablation which served as substrate for the re-entrant NSVT. This is the first case which describes NSVT from the epicardial RVOT as a complication from a previous endocardial ablation for idiopathic VPB.
我们报告一例罕见的起源于右心室流出道（RVOT）心外膜部分的非持续性室性心动过速（NSVT）病例。
一名37岁女性，2006年因特发性室性早搏（VPB）接受了RVOT消融治疗，2016年出现晕厥前NSVT。心脏检查未发现冠状动脉疾病，双心室功能正常，心脏磁共振成像无强化表现。代谢性正电子发射断层扫描排除了炎症。活检显示桥粒蛋白正常。心内膜标测显示RVOT前间隔区域存在低电压电位（<0.5 mV），对应于2006年首次消融的起始部位。激动标测显示提前程度不佳，起搏标测显示RVOT、左心室流出道和右冠状动脉瓣叶的形态不理想。心外膜标测显示RVOT前间隔区域存在低电压区，与心内膜瘢痕相对应的部位有碎裂电位。起搏标测显示完全匹配。诱发了NSVT，局部心电图显示舒张中期电位。在心外膜和心内膜进行了消融，无任何并发症。患者在4年随访期间无心律失常发作。
心脏检查排除了诸如致心律失常性心肌病、法洛四联症、结节病或心肌炎等特定疾病作为RVOT NSVT的病因。心外膜和心内膜标测显示首次消融后存在残留瘢痕，这成为折返性NSVT的基质。这是首例将心外膜RVOT的NSVT描述为既往特发性VPB心内膜消融并发症的病例。
