External loop recorders: determinants of diagnostic yield in patients with syncope

Objectives

The purpose of the current study was to determine the optimal duration of external loop recorder (ELR) monitoring in patients with presyncope or syncope and to identify factors that predict failure to activate the device effectively.

Design

A multivariate analysis was performed using data from the Comparison Of Loop Recorders Against Holter in Patients with Syncope (COLAPS) trial, a prospective study comparing diagnostic utility of ELRs and Holter monitors for assessment of syncope.

Methods

Patients with failure to effectively activate ELRs were compared to those who were successful. This analysis was performed separately for failure of test transmission and for failure to successfully record and transmit data from symptomatic episodes. Patient characteristics were compared among the groups to determine risk factors for device failure.

Results

Among 78 patients who received ELRs, a test transmission was successfully performed by 84.5% of patients. Twenty-one percent of diagnoses were made within 48 hours, 50% at 15 days, and 90% at 33 days. Patients performing a successful test transmission were more familiar with technology, with ability to use a bank automatic teller machine being a significant independent predictor. Patients with a successful test transmission were, in turn, significantly more likely to record and transmit data from symptomatic episodes. Patients living alone were much less likely to use the loop recorder effectively. The presence of factors that may influence motivation to reach a diagnosis (degree of worry/fear of symptoms and impact on daily life) were associated with successful use of the device in a univariate analysis.

Conclusion

ELRs should be worn for at least 30 days to maximize their diagnostic yield. Patients who are unfamiliar with technology, live alone, or have low motivation to reach a diagnosis have a lower diagnostic yield from ELRs for assessment of syncope.     

置入式Holter诊断不明原因晕厥的应用研究

目的探讨置入式Holter(ILR)在诊断不明原因晕厥和指导治疗中的临床价值。方法入选2002年10月至2005年5月求治的不明原因晕厥患者10例,男性4例,女性6例,平均年龄(41±22)岁。有2次以上晕厥或近似晕厥史平均为(4.5±1.4)次/例,经常规检查未能明确晕厥原因。均选用Medtronic公司RevealPlus(9526型ILR。结果10例患者平均随访(17.8±6.6)个月,ILR有效监测时间平均(15.3±3.6)个月,监测期内6例患者再发晕厥或近似晕厥24次。7例患者手动触发19段心电图,ILR自动触发记录460段心电图,共记录211段心电图为心律失常事件。根据症状-心律相关性,7例患者明确为心律失常性晕厥,1例患者明确为非心律失常性晕厥;2例仍不能明确晕厥原因。提示ILR诊断晕厥的效率为80%。10例依据ILR监测结果得到相应治疗,晕厥发作减少或消失。结论ILR用于诊断不明原因晕厥和先兆晕厥安全、高效、长程,可证实或排除患者的部分晕厥或近似晕厥系心律失常所致;具有微创、简单、监测期长、信息量大等优点,可作为现有晕厥诊断方法的重要补充。加强患者的依从性和动态优化工作参数,将进一步提高ILR的诊断价值。     

Implantable loop recorders in the investigation of unexplained syncope: a state of the art review

Since its introduction 15 years ago, the implantable loop recorder (ILR) has become the investigative tool of choice in recurrent unexplained syncope following negative initial investigations. This is based on very few randomised controlled clinical trials and modestly sized observational studies. Further controlled data are required to inform clinical practice with attention focused on empowering ILR-guided diagnosis, establishing the optimal timing of ILR use in syncope and embracing new technological advancements.     

Additional diagnostic value of very prolonged observation by implantable loop recorder in patients with unexplained syncope

Long‐Term Observation with ILR . Introduction : In the literature, the average diagnostic yield of the implantable loop recorder (ILR) is reported to be 35% over an observation period generally less than 18 months. The aim of this study was to evaluate the diagnostic value of ILR during very prolonged observation. Methods and Results: Consecutive patients who had received one or more (in the case of battery exhaustion before diagnosis) ILR (Reveal/plus/DX, Medtronic Inc.) from 2001 to 2010 were included. The diagnostic ECG was classified according to the ISSUE classification. We analyzed 157 patients (87 males, 69 ± 14 years): 70 of these were followed up for ≥18 months. The estimated cumulative diagnostic rates were 30%, 43%, 52%, and 80% at 1, 2, 3, and 4 years, respectively; 26% of diagnoses were made after 18 months. The diagnostic yield was independent of structural heart disease, bundle branch block, number of syncopes, age, and gender; the median time to diagnosis of ISSUE type 1 patients was shorter than that of the others (4 [2;10] vs. 16 [6;23] months; P = 0.003). During the observation period, 3 patients (1.9%) died and none suffered arrhythmic death. Conclusions: Prolonging observation up to 4 years increased the diagnostic value of ILR in syncopal patients and was safe. A quarter of patients diagnosed needed more than 18 months of follow‐up. As consequence, when a strategy of prolonging monitoring is chosen, monitoring should be maintained even for several years until diagnosis is established. (J Cardiovasc Electrophysiol, Vol. 23, pp. 67‐71, January 2012)     

The clinical impact of implantable loop recorders in patients with syncope.

AIMS: Implantable loop recorders (ILR) provide an opportunity to record ECG data from a spontaneous syncopal event. We conducted a randomized study to investigate the impact of the Reveal Plus ILR on an unselected population of patients with recurrent syncope. Initial follow-up (at least 6 months) did not demonstrate a reduction in syncopal events or an improvement in quality of life. We report the planned extension of follow-up to 18 months. METHODS AND RESULTS: All patients presenting acutely with recurrent unexplained syncope over a 16-month period, following a basic clinical work-up, were randomized to receive the ILR or conventional investigation and management. A total of 421 patients presented, 201 were eligible, median age 74, (IQ range 61-81) 54% female, with median syncopes 3 (IQ range 2-6). Median follow-up 17 months (IQ range 9-23). 42 (43%) of ILR patients and 8 (6%) of conventional patients received an ECG diagnosis (hazard ratio 6.53, 95% CI 3.73-11.4, P<0.001). Time to second syncope was significantly longer for ILR patients, although of borderline significance (P=0.04). A greater variety of diagnoses and treatments were seen in ILR patients. ILR patients had fewer post-randomization investigations and fewer days in hospital; however, cost savings were not statistically significant. There was improved quality of life in the ILR group (visual analogue scales, P=0.03) for general wellbeing. Overall mortality was 12% with no difference between the two groups. CONCLUSION: Investigation by the ILR significantly increases the diagnostic rate and ECG directed treatments in a typical unselected syncopal population. Long-term follow-up has demonstrated a significant subsequent reduction in syncopal events with improved quality of life.     

Use of implantable loop recorders in the diagnosis and management of syncope.

BACKGROUND: Syncope is a common, disabling symptom. The most useful data for diagnosing and managing syncope is the recording of physical parameters such as the ECG and blood pressure during a spontaneous event. Implantable loop recorders (ILR) provide an opportunity to record ECG data from a spontaneous event. The purpose of the Eastbourne Syncope Assessment Study (EaSyAS) was to investigate the impact of ILRs on an unselected population of syncopal patients presenting acutely to our institution. METHODS: All patients presenting acutely with recurrent, unexplained syncope over a 16-month period, were randomised after a basic clinical workup to receive the Reveal Plus ILR or conventional investigation. All patients were followed up for at least 6 months (mean 276+/-134 days) following randomisation. The primary outcome measure was time to ECG diagnosis. RESULTS: Four hundred twenty-one patients presented, 201 were eligible, median age 74 years (interquartile range 61-81 years), 54% female, with a median of three previous syncopes (IQ range 2-6). Thirty-three percent of ILR patients and 4% of conventional patients had an ECG diagnosis (hazard ratio 8.93, 95% CI 3.17-25.2, p < or = 0.0001). Introduction of ECG-directed therapy was quicker for ILR patients (hazard ratio 7.9, 95% CI 2.8-22.3, p < 0.0001). ILR patients had fewer post-randomisation investigations and fewer hospital days, resulting in a saving of costs, 406 UK pounds versus 1210 UK pounds (mean difference 809 UK pounds, 95% CI 123-2730 UK pounds). There was no difference in the number of subsequent syncopal episodes, mortality, or quality of life. CONCLUSIONS: LR significantly increased the rate of diagnosis in an unselected Western population with recurrent syncope. There was a significant decrease in the rates of hospitalisation and investigation in patients receiving an ILR.     

Use of the implantable loop recorder in patients with unexplained syncope

Syncope is a complex clinical syndrome with multiple etiologies that can be very difficult to diagnose. The major obstacles to diagnosis are the periodic and unpredictable nature of events and the high spontaneous remission rate. Conventional testing is often unproductive in patients when initial non-invasive testing is negative, particularly when a paroxysmal ar-rhythmia is suspected. Holter monitoring is often employed initially, with limited utility. Holter monitoring provides a rhythm profile, but rarely achieves the gold standard of a symptom rhythm correlation. The external loop re-corder extends the period of monitoring, enhancing the diagnostic yield to as high as 60% in patients with symptoms likely to recur during a month of device use. Finally, implantable loop recorders further extend the ability to monitor cardiac patients, enhancing the diagnostic yield to as high as 85% in difficult to diagnose syncope. Several recent studies suggest that prolonged monitoring with an implantable loop recorder has a role in patients with syncope and conduction disturbances, negative tilt testing, unexplained seizures and may be superior to conventional testing with tilt and electrophysiologic studies in select patients.     

Digital implantable loop recorders in the investigation of syncope in children: Benefits and limitations

BACKGROUND: Conventional diagnostic methods for detecting arrhythmogenic causes of syncope in children are poor. Digital implantable loop recorders are of proven value in adults. OBJECTIVES: The purpose of this study was to evaluate digital implantable loop recorders in the investigation of syncope in children. METHODS: We reviewed the clinical and technical records of 18 consecutive patients (6 female and 12 male; age 相似文献   

Initial experience with an implantable loop recorder in patients with unexplained syncope

Patients with recurrent syncope undiagnosed after extensive noninvasive and invasive testing pose a diagnostic and therapeutic dilemma. Holter monitoring is non-diagnostic in 90% of cases. Recent developments in loop recorder technology permit longterm ECG monitoring in patients with recurrent unexplained syncope. The implantable loop recorder monitors a single lead electrogram continuously using 2 sensing electrodes on the device shell. The device was implanted in 20 patients (11 male, 9 female) with the history of recurrent syncope. During a mean follow-up of 12+/-6 months after device implantation, 11 patients (55%) experienced syncope (8 pts) or presyncope (3 pts). In the remaining 9 patients, no syncope occurred. In all 11 patients with syncope or presyncope during follow-up, loop recording definitively determined whether an arrhythmia was the cause of symptoms or not. Diagnosis included bradycardia in one patient, tachycardia in two patients, in one patient two rhythm disturbances were revealed: frequent ventricular premature beats with bigemini and atrial flutter. Two patients had a neurocardiogenic syncope. Syncope was nonarrhythmic in 5 patients. An implantable loop recorder is useful for establishing the diagnosis if symptoms are recurrent but too infrequent for conventional monitoring techniques.     

植入型心电事件记录仪在不明原因晕厥中的应用价值:单中心经验

目的探讨植入型心电事件记录仪(ILR)在不明原因晕厥患者中的应用价值,并筛选可能的心律失常源性晕厥预测因素。方法连续入选2013年1月至2018年10月在大连医科大学附属第一医院诊断为不明原因晕厥,且植入ILR的患者37例,年龄(59±19)岁,男24例。植入后进行常规随访,每3~6个月进行1次随访,主要随访内容:症状、程控事件、是否发生晕厥。如患者发生晕厥,通知回院就诊,接受程控和心电学检查,分析晕厥病因及心律失常类型和相关危险因素。结果共22例(59.46%,22/37)患者记录到晕厥事件,其中9例为窦性心动过缓或窦性停搏,6例为三度或高度房室传导阻滞,1例为室性心动过速,2例为室上性心动过速,4例为心房颤动(房颤)伴RR长间歇(>2 s),在植入后(187.73±177.12)d发生晕厥事件。1例患者记录到房颤伴RR长间歇,但未发生晕厥。16例患者植入永久起搏器,1例患者植入心律转复除颤器,2例患者行导管消融治疗。对性别、年龄、合并基础疾病、植入前晕厥次数、心电信息等进行分析发现,动态心电图中存在RR长间歇(>2 s)是预测晕厥发作的影响因素。结论植入ILR可使不明原因晕厥患者获得明确诊断并接受相应治疗,ILR是明确晕厥病因的有效手段之一。动态心电图中存在RR长间歇(>2 s)是心律失常原因晕厥的重要预测因素。     

The diagnostic value of ATP testing in patients with unexplained syncope.

A minority of patients with unexplained syncope has an increased susceptibility to adenosine triphosphate (ATP) injection. In these 'hypersensitive' patients, owing to its powerful cardiac and hypotensive effects, endogenous adenosine released under physiological and pathological conditions could trigger bradycardia and/or hypotension and cause syncope. This hypothesis still needs to be proven. However, there is some evidence that the ATP test identifies a group of patients with otherwise unexplained syncope with definite clinical features, absence of structural heart disease and benign prognosis. The mechanism of syncope is heterogeneous; indeed, in cases of electrocardiographic documentation of spontaneous syncope, either a long ventricular pause (mainly due to paroxysmal atrioventricular (AV) block) or no rhythm variations or even tachycardia were documented. ATP-positive patients have clinical features and mechanisms of syncope which are different from tilt-positive patients. Owing to its low positive predictive value, the ATP test is of little value in selecting treatment. A favourable outcome suggests a strategy of postponing treatment, in particular pacemaker therapy, until a definite diagnosis can be made by documenting a spontaneous syncopal relapse.     

Comparison of automatic and patient-activated arrhythmia recordings by implantable loop recorders in the evaluation of syncope

The implantable loop recorder (ILR) has become an important tool for evaluating patients with recurrent syncope. Second generation ILRs have the ability to record events either automatically (auto activated) or by manual activation (patient activated). In an attempt to evaluate the relative utility of the auto-activation feature, this study stratified ILR events based on a grading system designed to classify detected arrhythmias in terms of the likelihood that they provide a diagnostic basis for syncope. Data from 50 patients (27 men, mean age 64 +/- 22 years) who underwent ILR implantation for investigation of recurrent syncope were assessed. The arrhythmia syncope grading system used 5 levels, ranging from grade 0 (rhythm recorded during syncope) to grade IV (rhythm unlikely to provide a diagnostic basis for syncope). Thirty-six patients (72%) demonstrated > or =1 auto-activated or patient-activated recording during a follow-up of 14.3 +/- 7.9 months. Of the total of 529 recordings, 223 (194 after auto activation [86.9%]) from 30 patients showed a rhythm abnormality. Auto activation was more effective for documenting arrhythmias that were recorded during syncope or those with highest probability of providing a syncope diagnosis (grade 0 or I arrhythmias: auto activated, 19 patients, patient activated, 3 patients). Times from ILR implantation to first grade 0 and grade I arrhythmias were 13.4 and 7.8 months, respectively. The ILR auto-activation feature proved effective in providing a high probability basis for syncope (196 arrhythmia recordings [87.1%] in 27 patients) and enhanced the diagnostic effectiveness of the device compared with patient activation alone (29 arrhythmia recordings [12.9%] in 6 patients).