Wang Li
Medtronic, Inc., Minneapolis, Minnesota, USA.
Am J Cardiol. 2007 May 21;99(10A):3G-10G. doi: 10.1016/j.amjcard.2007.02.009. Epub 2007 Mar 9.
The primary objective of the first-generation implantable cardiac pacemakers was to provide critical heart rate support, but these devices did not have any diagnostic capabilities. In the intervening decades, the number, type, and complexity of implantable devices has greatly expanded. Today, implantable devices not only provide heart rate support but they also provide protection from sudden cardiac death with implantable cardioverter defibrillators (ICDs) and reduce symptoms and increase survival with cardiac resynchronization therapy (CRT). Furthermore, information on physiologic variables has been collected in patients with implanted devices for the purpose of providing sophisticated closed-loop optimization of their pacing and defibrillation algorithms. Thoracic fluid status monitoring via intrathoracic impedance is the newest device-based diagnostic capability. For those patients with heart failure who are already targeted to receive an ICD or CRT with defibrillator implant, the ability to monitor fluid status can provide additional insight into the difficult problem of evaluating and managing these patients. This article reviews the basics of measuring intrathoracic impedance via OptiVol fluid status monitoring (Medtronic, Inc., Minneapolis, MN), as well as clinical results regarding the utility of evaluating OptiVol intrathoracic impedance data trends.
第一代植入式心脏起搏器的主要目标是提供关键的心率支持，但这些设备没有任何诊断功能。在随后的几十年里，植入式设备的数量、类型和复杂性有了极大的扩展。如今，植入式设备不仅能提供心率支持，还能通过植入式心脏复律除颤器（ICD）预防心脏性猝死，并通过心脏再同步治疗（CRT）减轻症状、提高生存率。此外，为了对起搏和除颤算法进行复杂的闭环优化，已收集了植入设备患者的生理变量信息。通过胸腔内阻抗监测胸腔液体状态是最新的基于设备的诊断功能。对于那些已被确定要接受ICD或带除颤器植入的CRT治疗的心力衰竭患者，监测液体状态的能力可以为评估和管理这些患者这一难题提供更多见解。本文回顾了通过OptiVol液体状态监测（美敦力公司，明尼阿波利斯，明尼苏达州）测量胸腔内阻抗的基础知识，以及评估OptiVol胸腔内阻抗数据趋势效用的临床结果。
