Virk Sohaib A, Keren Arieh, John Roy M, Santageli Pasquale, Eslick Adam, Kumar Saurabh
Department of Cardiology, Westmead Hospital, Sydney, NSW, Australia.
Cardiology Department, Sir Charles Gardiner Hospital, Perth, WA, Australia.
Heart Lung Circ. 2019 Jan;28(1):134-145. doi: 10.1016/j.hlc.2018.10.006. Epub 2018 Oct 17.
Mapping of scar-related ventricular tachycardia (VT) in structural heart disease is fundamentally driven by identifying the critical isthmus of conduction that supports re-entry in and around myocardial scar. Mapping can be performed using activation and entrainment techniques during VT, or by substrate mapping performed in stable sinus or paced rhythm. Activation and entrainment mapping requires the patient to be in continuous VT, which may not be haemodynamically tolerated, or, if tolerated, may lead to adverse sequelae related to impaired end organ perfusion. Mechanical circulatory support (MCS) devices may facilitate haemodynamic stability and preserve end organ perfusion during sustained VT to permit mapping for long periods. Available options for haemodynamic support include an intra-aortic balloon pump (IABP), TandemHeart left atrial to femoral artery bypass system (CardiacAssist Inc., Pittsburgh, PA, USA), Impella left ventricle (LV) to aorta flow-assist system (Abiomed, Danvers, MA, USA), and extracorporeal membrane oxygenation (ECMO); the bypass and assist devices provide far better augmentation of cardiac output than IABP. MCS has potential key advantages including maintenance of vital organ perfusion, reduction of intra-cardiac filling pressures, reduction of LV volumes, wall stress, and myocardial consumption of oxygen, and improvement of coronary perfusion during prolonged periods of VT induction and/or mapping. Observational studies show MCS allows for longer duration of mapping, and increased likelihood of VT termination, without an increased risk of peri-procedural mortality or VT recurrence in follow-up, despite being used in a significantly sicker cohort of patients. However, MCS has increased risk of complications related to vascular access, bleeding, thromboembolic risk, mapping system interference, increase procedural complexity and increased cost. Acute haemodynamic decompensation occurs in ∼11% of patients undergoing VT ablation, and is associated with increased mortality. Prospectively identifying patients at risk of acute haemodynamic decompensation in the peri-procedural period may allow prophylactic MCS. Although observational studies of MCS in patients at high risk of haemodynamic decompensation are encouraging, its benefit needs to be proven in randomised trials. This review will summarise the indication for MCS, forms of MCS, procedural outcomes, complications and utility of MCS during VT ablation.
结构性心脏病中与瘢痕相关的室性心动过速（VT）的标测，其根本驱动因素是识别支持心肌瘢痕内及周围折返的关键传导峡部。标测可在室性心动过速期间使用激动和拖带技术进行，也可在稳定的窦性或起搏心律下进行基质标测。激动和拖带标测要求患者持续处于室性心动过速状态，这可能在血流动力学上无法耐受，或者，如果耐受，可能会导致与终末器官灌注受损相关的不良后果。机械循环支持（MCS）设备可在持续性室性心动过速期间促进血流动力学稳定并维持终末器官灌注，从而允许长时间进行标测。可用的血流动力学支持选项包括主动脉内球囊反搏（IABP）、TandemHeart左心房至股动脉旁路系统（美国宾夕法尼亚州匹兹堡市CardiacAssist公司）、Impella左心室（LV）至主动脉血流辅助系统（美国马萨诸塞州丹弗斯市Abiomed公司）以及体外膜肺氧合（ECMO）；旁路和辅助设备在心输出量增加方面比IABP提供更好的支持。MCS具有潜在的关键优势，包括维持重要器官灌注、降低心内充盈压、减少左心室容积、壁应力和心肌氧消耗，以及在长时间室性心动过速诱发和/或标测期间改善冠状动脉灌注。观察性研究表明，MCS可实现更长时间的标测，增加室性心动过速终止的可能性，尽管用于病情严重得多的患者队列，但随访期间围手术期死亡率或室性心动过速复发风险并未增加。然而，MCS与血管通路、出血、血栓栓塞风险、标测系统干扰、手术复杂性增加和成本增加相关的并发症风险增加。约11%接受室性心动过速消融的患者会发生急性血流动力学失代偿，且与死亡率增加相关。前瞻性识别围手术期有急性血流动力学失代偿风险的患者可能允许进行预防性MCS。尽管对血流动力学失代偿高风险患者进行MCS的观察性研究令人鼓舞，但其益处仍需在随机试验中得到证实。本综述将总结MCS在室性心动过速消融期间的适应证、MCS的形式、手术结果、并发症和效用。
