Uppal Abhimanyu, Kathuria Sanjeev, Shah Bhushan, Trehan Vijay
Department of Cardiology, GB Pant Institute of Post Graduate Education and Research, MAMC, JLN Road, New Delhi 110002, India.
Eur Heart J Case Rep. 2021 Dec 7;5(12):ytab491. doi: 10.1093/ehjcr/ytab491. eCollection 2021 Dec.
Riata implantable cardioverter-defibrillator (ICD) leads are prone to a unique type of mechanical lead failure causing conductor externalization (CE) which may be complicated by a delayed-onset electrical lead failure (ELF).
A 60-year-old male with symptomatic, severe ischaemic cardiomyopathy, and atrial fibrillation following a prior anterior wall myocardial infarction received a dual-chamber ICD with 7F-RiataST ventricular lead as a primary prevention strategy against sudden cardiac death in 2008. In 2017, a pulse generator replacement was performed for elective replacement indicator status. At that time, CE was noted in the ventricular lead but the electrical lead parameters were normal, hence lead replacement was decided against and the patient was closely followed up thereafter. Four years later, the patient presented with multiple ICD shocks within 48 h. Implantable cardioverter-defibrillator interrogation showed noise on the ventricular electrogram (EGM) channel that was detected as ventricular fibrillation (VF) episodes, triggering inappropriate ICD therapy (five ICD detected VF events within 24 h triggering three antitachycardia pacing therapies and one shock). Lead impedance and R-wave amplitude were within normal range in supine position but dramatically worsened in sitting posture. A new ventricular lead was implanted and the old lead abandoned. The patient has not experienced any device therapy in the follow-up period.
An electrically inert CE of Riata ICD leads needs close follow-up because an ELF may occur even after several years. A careful analysis of EGMs including postural changes in lead parameters can aid in detection and better characterization of underlying electrical dysfunction following CE.
Riata植入式心脏复律除颤器（ICD）导线易于出现一种独特类型的机械性导线故障，导致导线导体外露（CE），这可能并发迟发性电气性导线故障（ELF）。
一名60岁男性，有症状性严重缺血性心肌病，既往前壁心肌梗死后出现心房颤动，于2008年接受了带有7F-RiataST心室导线的双腔ICD，作为预防心脏性猝死的一级预防策略。2017年，因择期更换指征状态进行了脉冲发生器更换。当时，在心室导线上发现了CE，但电气导线参数正常，因此决定不更换导线，此后对患者进行密切随访。四年后，患者在48小时内出现多次ICD电击。植入式心脏复律除颤器问询显示心室电图（EGM）通道上有噪声，被检测为室颤（VF）发作，触发了不适当的ICD治疗（24小时内ICD检测到5次VF事件，触发了3次抗心动过速起搏治疗和1次电击）。仰卧位时导线阻抗和R波振幅在正常范围内，但坐位时显著恶化。植入了一根新的心室导线，并废弃了旧导线。在随访期间，患者未经历任何器械治疗。
Riata ICD导线的电惰性CE需要密切随访，因为即使几年后也可能发生ELF。仔细分析EGM，包括导线参数的体位变化，有助于检测和更好地表征CE后潜在的电功能障碍。
