Kadhiresan Kadir, Carlson Gerrard
Department of Applied Research, Guidant Corporation, St.Paul, MN 55112, USA.
Stud Health Technol Inform. 2004;108:219-27.
Heart failure is a chronic disease with significant morbidity and mortality worldwide. Drugs such as ACE-inhibitors, beta-blockers and diuretics have helped control heart failure but the incidence of hospitalizations remains high. Rigorous continuous monitoring of patients and tailored therapy based on individual clinical and hemodynamic profile has been shown to limit the symptoms of heart failure. Self-monitoring or prescribed frequent in-clinic monitoring is logistically difficult and is fraught with patient non-compliance. Consequently, implantable sensors that can monitor patient's clinical status on a continuous basis are desirable. The disadvantage with an implantable sensor is obviously that the patient has to undergo an invasive procedure, which in itself has a certain risk, although minimal, associated with it. In addition, the risk of having an implantable device has to be weighed against the benefit of monitoring the patient on a continuous basis. The risk benefit question has been answered in part by the recent success of cardiac resynchronization therapy (CRT) in treating symptoms of heart failure. A recent study has performed a meta analysis on major heart failure trials conducted to date and concluded that CRT reduces mortality and morbidity. The CRT device is a specialized pacemaker with capabilities of continuous heart monitoring and embedded therapeutic decisions. A trend of heart rates offers significant insights into the progression of heart failure and patient status. In addition, using complex algorithms, several of the heart rate variability (HRV) parameters, identified in several studies for risk stratification and prognostication, can also be calculated. Furthermore, in recent devices based on heart rate intervals, autonomic balance (critical measure of progression of heart failure) can be estimated with sophisticated algorithms. Finally, technologies that can monitor patients' activity e.g. accelerometers, can be easily incorporated into the device. Such measures may be used to evaluate the efficacy of a new therapy or simply to provide patient status. Based on advances in technology, several patient clinical features can be monitored and trended over time. The measured metrics will help form a comprehensive and objective clinical profile of the patient that the physician can act upon. Prospective studies are needed to answer the efficacy of such diagnostic measures in management of heart failure.
心力衰竭是一种在全球范围内具有显著发病率和死亡率的慢性疾病。诸如血管紧张素转换酶抑制剂、β受体阻滞剂和利尿剂等药物有助于控制心力衰竭，但住院率仍然很高。对患者进行严格的持续监测并根据个体临床和血流动力学特征进行个性化治疗已被证明可以减轻心力衰竭的症状。自我监测或规定的频繁门诊监测在后勤方面存在困难，并且患者依从性差。因此，需要能够持续监测患者临床状态的植入式传感器。植入式传感器的缺点显然是患者必须接受侵入性手术，尽管风险极小，但该手术本身仍存在一定风险。此外，必须权衡植入式设备的风险与持续监测患者的益处。心脏再同步治疗（CRT）近期在治疗心力衰竭症状方面取得的成功部分回答了风险效益问题。最近的一项研究对迄今为止进行的主要心力衰竭试验进行了荟萃分析，得出结论认为CRT可降低死亡率和发病率。CRT设备是一种具有持续心脏监测能力和嵌入式治疗决策功能的特殊起搏器。心率趋势可为心力衰竭的进展和患者状态提供重要见解。此外，使用复杂算法，还可以计算出多项在多项研究中用于风险分层和预后评估的心率变异性（HRV）参数。此外，在基于心率间期的最新设备中，可以通过复杂算法估计自主神经平衡（心力衰竭进展的关键指标）。最后，能够监测患者活动的技术，如加速度计，可以很容易地集成到设备中。这些措施可用于评估新疗法的疗效或简单地提供患者状态。基于技术进步，可以监测多个患者临床特征并随时间进行趋势分析。所测量的指标将有助于形成医生可以据此采取行动的患者全面、客观的临床概况。需要进行前瞻性研究来回答此类诊断措施在心力衰竭管理中的疗效。
