Cost implications of testing strategy in patients with syncope: randomized assessment of syncope trial

An Investigation of Metabolic Risk Factors and Gut Microbiota in Unexplained Syncope

BACKGROUND

The pathogenesis of many syncopal episodes remains unexplained. Intestinal dysbiosis could be involved in the pathophysiological mechanisms of syncope due to its connection with the central nervous system via the microbiota-gut-brain axis. This pilot study aimed to explore the specific cardiometabolic risk factors and gut microbiota in unexplained syncope (US), compared to other types of syncope, to assess their similarity or verify their different origins.

METHODS

We studied 86 participants with syncope, who were divided into four groups: an orthostatic syncope group (OH, n = 24), a neuromediated syncope group (NMS, n = 26), a cardiological syncope group (CS, n = 9), and an unexplained syncope group (US, n = 27). We evaluated the anthropometric, clinical, and metabolic characteristics of the four groups; the α- and β-diversity; and the differences in the abundance of the microbial taxa.

RESULTS

The US group had a lower incidence of systolic hypertension at the first visit and a lower frequency of patients with nocturnal hypertension than the CS group. Compared to the OH and NMS groups, the US group had a higher incidence of carotid plaques and greater carotid intima-media thickness, respectively. The microbiota differed significantly between the US and CS groups, but not between the US group and the OH or NMS group.

CONCLUSIONS

We observed significant differences in the gut microbiota between CS and US. Future studies are necessary to evaluate the involvement of the gut microbiota in the complex pathogenesis of syncope and whether its analysis could support the interpretation of the pathophysiological mechasnisms underlying some episodes classifiable as US.

A comparison of Atrial Fibrillation Detection Strategies After Ischemic Stroke-A Retrospective Study

Objective of this retrospective study was to determine if long-term continuous cardiac monitoring with Implantable loop recorder (ILR) in patients with Cryptogenic strokes or TIA is superior at detecting Atrial Fibrillation (AF) than 30-day Event Monitor (EM) and 48-hour Holter Monitor (HM). Furthermore, we aimed to deduce if uncovering AF leads to lower risk of future ischemic strokes, or reduction in mortality. In 20%-30% cases, the cause of stroke remained unexplained after diagnostic workup which has led to coining of the term, Cryptogenic Stroke (CS). Undiagnosed AF is a prime suspect in CS, but guidelines do not recommend initiation of anticoagulation unless AF has formally been detected. IRB approved retrospective study included patients with at least 1 episode of ischemic stroke or TIA without identifiable cause and was monitored with either HM, EM or ILR to diagnose any undiscovered AF. All patients (n = 531) had at least 1 year, and up to 3 years, of follow-up after device placement. Chi-Squared analysis and Multivariable logistic regression demonstrated no statistically significant difference among 3 devices for detection of AF within 1 month of index stroke but a significant difference in AF detection was observed at 6, 12 and 24 months. Cox proportional hazard model showed device type had no significant impact on secondary outcomes: Subsequent ischemic stroke or TIA, Initiation of anticoagulation, Mortality and Incidence of major bleeding. Despite the superiority of AF detection by ILR, it is not superior to HM or EM in lowering the risk of subsequent stroke or TIA, or in reducing mortality.

Diagnostic usefulness of implantable loop recorder in patients with unexplained syncope or palpitation

Background

In a substantial proportion of patients with syncope, the exact cause is not identified because of the difficulty to document electrocardiograms correlated with the events during a syncope episode. Thus, an implantable loop recorder (ILR) was introduced for diagnosing hidden arrhythmia; however, its clinical use remains limited. Therefore, we conducted a retrospective analysis to assess the diagnostic value of the ILR in patients with unexplained syncope or palpitations.

Methods

All patients who had undergone ILR implantation from May 2016 to January 2020, were studied retrospectively. We analyzed their electrocardiogram stored in the device.

Results

Among the 70 patients (mean age ± SD; 50.2 ± 20.3 years, 27 men) with unknown causes of syncope or palpitation, during two years follow-up, arrhythmia was detected in 26 patients (37.1%). Nineteen (73.1%) patients underwent permanent pacemaker implantation due to symptomatic bradycardia or atrioventricular block. All arrhythmias were detected within 6 days to 39 months after loop recorder implantation. Thirteen patients (50%) showed sick sinus syndrome (eight long pauses and five tachycardia-bradycardia syndromes). Eleven patients (42.3%) had paroxysmal atrioventricular block. Two patients who underwent permanent pacemaker implantation showed a positive tilt-table test. Three patients underwent radiofrequency catheter ablation for paroxysmal supraventricular tachycardia and atrial fibrillation. The mean duration for the detection of first sign (arrhythmia or palpitations) was 7.5 months, and the time from the detection of arrhythmia to ablation or device implantation was 3.4 months.

Conclusion

ILR monitoring detected a substantial number of significant bradycardias in patients with unexplained syncope and palpitations, suggesting that it is an effective diagnostic method that can shorten the time required to identify the cause of arrhythmias.

Clinical predictors of cardiac syncope in patients with unexplained syncope after the implantation of an insertable cardiac monitor

Syncope prognosis is related to both its etiology and comorbidities, with cardiac syncope (CS) having higher risks for mortality and cardiovascular events than syncope of non-cardiac causes. Although a novel insertable cardiac monitor (ICM) is an effective diagnostic tool for unexplained syncope, decision regarding ICM implantation with a high pre-test likelihood of CS should contribute to economic cost reduction and avoidance of unnecessary complications. This study aimed to investigate clinical factors associated with CS after ICM implantation in patients with unexplained syncope. This retrospective observational study included 31 consecutive patients with ICM implantation for syncope between September 2016 and August 2021. The initial examinations for syncope included a detailed history, physical examination, blood tests, 12-lead electrocardiograms, and transthoracic echocardiography. Of the 31 patients, 13 (41.9%) experienced recurrent CS during follow-up (676 ± 469 days). Among several clinical factors, syncope-related minor injuries (p = 0.017) and higher brain natriuretic peptide (BNP; p = 0.043) levels were significantly associated with CS. Moreover, multivariable analysis showed that both syncope-related minor injuries (odds ratio, 11.2; 95% confidence interval, 1.4-88.4; p = 0.022) and BNP higher than 64.0 pg/mL (odds ratio, 7.0; 95% confidence interval, 1.1-44.2; p = 0.038) were independent predictors of CS after ICM implantation. In conclusion, a history of minor injury secondary to syncope and higher BNP levels were independent CS predictors in patients receiving ICM for syncope. These results emphasized the utility of ICM implantation early in the diagnostic journey of patients presenting with CS predictors requiring specific treatments.

Subcutaneouscardiac Rhythm Monitors: A Comprehensive Review

Subcutaneous loop recorders (SCRMs) are subcutaneous electronic devices which have revolutionized the field of arrhythmia detection. They have become increasingly appealing due to advances such as miniaturization of device, longer battery life, bluetooth capabilities and relatively simple implantation technique without the need for complex surgical suites. They can be implanted in the office, patient bedside without the need to go to the operating room. One of the most common indications for their implantation is detection of atrial fibrillation (AF) after a cryptogenic stroke. They have also been utilized for assessing the success of rhythm control strategies such post pulmonary venous isolation. More recently studies have assessed the utility of SCRMs for detecting silent AF in at risk populations such as patients with sleep apnea or those on hemodialysis. In this paper, we review the evolution of SCRMs, the clinical studies assessing their value for different indications, their role incurrent clinical practice and future avenues in the era of smart wearable devices like apple watch etc.

R-wave amplitude changes with posture and physical activity over time in an insertable cardiac monitor

Background

Insertable cardiac monitors (ICMs) are accepted tools in cardiac arrhythmia management. Consistent R-wave amplitude (RWA) is essential for optimal detection.

Objectives

Assess RWAs with posture/activities at insertion and at 30 days.

Methods

Participants (n = 90) with Confirm Rx™ ICM had RWAs measured in different postures (supine, right-side [RS], left-side [LS], sitting, and standing) and defined physical activities (including isometric push [IPUSH] and pull) at 2 time points. ICMs were inserted in 45° to sternum and parasternal orientations.

Results

There were significant reductions at insertion with RS, LS, sitting, or standing vs supine (reference position) (all P < .05). At 30 days, significant changes only occurred with LS and sitting (P < .05). Sex had an effect on RWAs, with females having significant variability at insertion (supine vs RS, LS, sitting, standing, and IPUSH; all P < .05). Males showed large RWA interpatient variabilities but minimal differences between positions vs supine. At 30 days, RS, LS, and sitting positions remained significant for females (P < .05), while in males RWAs were higher than at insertion for most postures and activities. The orientation 45° to sternum had consistently higher RWAs vs parasternal orientation at both time points (P < .0001). In females, ICM orientation had no significant effect on RWAs; however, in males the 45° to sternum produced higher RWAs. ICM movement from the insertion site showed no correlation with RWA changes.

Conclusion

The mean RWAs were higher at 30 days with less interparticipant and interpostural variability; males had higher RWAs compared to females; 45° to sternum orientation had higher RWAs; and ICM migration from the insertion site did not affect RWAs.

Clinical Significance of the Head-Up Tilt Test in Improving Prognosis in Patients with Possible Neurally Mediated Syncope

Simple Summary

Several diseases can cause syncope, which is commonly known as fainting; however, syncope triggered by a reflex mechanism, also termed neurally mediated syncope (NMS), is one of the most common forms. While NMS is considered a benign disease, it can cause critical clinical events, such as severe trauma due to syncope. The head-up tilt test (HUTT) is one of the modalities for the diagnosis of NMS. The clinical significance of HUTT in the prognosis of NMS, such as recurrence rate of syncope and mortality, are still to be elucidated. This research aimed to clarify the value of HUTT for the diagnosis of NMS, and to investigate the prognosis of patients with NMS by analyzing the data of 101 patients with syncope and their close long-term (four years at the longest) follow-up. Furthermore, as insertable cardiac monitors (ICMs) are considered effective in patients with syncope, this study also aimed to evaluate the usefulness of ICM in patients with negative HUTT results. Finally, our research contributes to the improvement of the clinical management for patients with syncope.

Abstract

Syncope is commonly encountered in daily clinical practice. Depending on its etiology (benign or life-threatening conditions or environmental triggers), syncope can be neurally mediated (reflex), cardiac, or orthostatic. Furthermore, neurologic disease can cause symptoms that mimic syncope. However, there is limited research on neurally mediated syncope (NMS), which is considered a benign disorder, and close follow-ups are rarely performed. NMS can cause serious clinical events, including severe trauma and car accidents. The head-up tilt test (HUTT) is the gold standard for diagnosing NMS; however, its clinical significance remains unknown, and its relevance to NMS prognosis requires further research. This retrospective study aimed to assess the clinical significance of the HUTT for NMS. We reviewed the charts of 101 patients who underwent HUTT at Tokai University Hospital in Japan between January 2016 and March 2019. During the HUTT, 72 patients (69.2%) experienced syncope. Patients were followed up for 886.1 ± 457.7 days (interquartile range: 518–1293 days). The syncope recurrence rate was 16.9%; however, no significant difference was observed between the two groups (HUTT positive vs. negative) (13.8% vs. 18.1%, p = 0.772). Four of 29 (13.9%) and two of 72 (2.8%) patients in the negative and positive HUTT groups, respectively, experienced cardiac events (p = 0.019). Negative HUTT results may assist in anticipating unexpected clinical events within a few years. A negative HUTT result may allow us to reconsider the NMS diagnosis based on clinical information. Close outpatient follow-up of patients with negative HUTT results is warranted.

Diagnostic value of implantable loop recorders in patients with unexplained syncope or palpitations

Background

The implantable loop recorder (ILR) is a small cardiac rhythm‐monitoring device. Our aim was to determine ILR diagnostic value in patients with unexplained syncope, presyncope, or palpitations suggesting cardiac arrhythmias.

Methods

This has been a retrospective, observational, single‐center study. We included 181 patients in whom ILR was implanted at the Clinical Center of Serbia between January 2006 and July 2019. An event was marked as diagnostic if it led to a diagnosis and ILR was considered diagnostic if it verified or excluded an arrhythmia as the cause of syncope or palpitations.

Results

The mean age was 51.8 ± 17.8 years and 94 (51.9%) were male. The mean follow‐up period was 20.2 ± 15.8 months. ILR was diagnostic in 98 patients (54.1%). There was no significant difference in diagnostic value of ILR in regard to the baseline patients’ characteristics. The mean time to occurrence of the diagnostic event was 11.1 ± 9.6 months. The time to occurrence of a diagnostic event did not differ significantly between patients who underwent basic as compared to extended diagnostics before ILR implantation.

Conclusions

ILR was able to achieve an etiological diagnosis in 54.1% of patients with unexplained syncope, presyncope, or palpitations suggesting cardiac arrhythmias. In a subgroup of patients with recurrent palpitations, ILR was significantly less diagnostic than in patients with syncope or presyncope. ILR should be implanted beforehand in syncope evaluation process.

[Implantable loop recorders for prolonged heart-rhythm monitoring in patients with cryptogenic stroke]

OBJECTIVE

The timely diagnosis of atrial fibrillation (AF) in patients with cardiac embolism with implantable loop recorders (ILR).

MATERIAL AND METHODS

Twenty-nine patients, hospitalized within 6 months after stroke (n=19) or transient ischemic attack (n=10), were included in the study. ILR were implanted in all cases. The mean time of follow-up was one year.

RESULTS

Five hundred and thirteen transmissions were detected during the whole follow-up period. Symptomatic episodes were recorded in 165 cases. Such episodes as bradycardia, asystole, AF, atrial tachycardia and ventricular tachycardia were recorded in 98 cases out of 348 planned transmissions. All transmissions were analyzed by an operator. However, 70 cases were false-positive because of ILR over-sensing. In total, arrhythmias were detected in 5 patients, including sick sinus syndrome (1), supraventricular tachycardia (1), ventricular tachycardia (1) and atrial fibrillation (3). Anticoagulant therapy was started immediately after the diagnosis of AF.

CONCLUSION

Loop recording monitoring is an effective strategy in patients with cardiac embolism for timely diagnosis and further treatment of arrhythmia.

Burden of recurrent syncope and injuries and the usefulness of implantable cardiac monitors: insights from a nationwide longitudinal cohort analysis

Aim: The study assesses the burden and costs of recurring unexplained syncope and injuries and the effectiveness of implantable loop recorders. Methods: The English national hospital database (Hospital Episode Statistics) was retrospectively analyzed. Results: 12,002 patients were identified with repeated syncope hospitalizations. 25% of patients were hospitalized at least once again for syncope, 9% of the patients were hospitalized at least once for an injury, causing substantial costs. In the second analysis: 10,902 patients implanted with an implantable cardiac monitor were tracked. By year 3, hospitalizations due to syncope had dropped by 60% versus pre-implantable cardiac monitor (ICM) levels. Conclusion: This study shows a high rate of recurrent syncope admissions and a parallel burden of hospitalizations for injuries. Use of an ICM appears to reduce syncope hospitalizations.

A nurse-led implantable loop recorder service is safe and cost effective

INTRODUCTION

Implantable loop recorders (ILR) are predominantly implanted by cardiologists in the catheter laboratory. We developed a nurse-delivered service for the implantation of LINQ (Medtronic; Minnesota) ILRs in the outpatient setting. This study compared the safety and cost-effectiveness of the introduction of this nurse-delivered ILR service with contemporaneous physician-led procedures.

METHODS

Consecutive patients undergoing an ILR at our institution between 1st July 2016 and 4th June 2018 were included. Data were prospectively entered into a computerized database, which was retrospectively analyzed.

RESULTS

A total of 475 patients underwent ILR implantation, 271 (57%) of these were implanted by physicians in the catheter laboratory and 204 (43%) by nurses in the outpatient setting. Six complications occurred in physician-implants and two in nurse-implants (P = .3). Procedural time for physician-implants (13.4 ± 8.0 minutes) and nurse-implants (14.2 ± 10.1 minutes) were comparable (P = .98). The procedural cost was estimated as £576.02 for physician-implants against £279.95 with nurse-implants, equating to a 57.3% cost reduction. In our center, the total cost of ILR implantation in the catheter laboratory by physicians was £10 513.13 p.a. vs £6661.55 p.a. with a nurse-delivered model. When overheads for running, cleaning, and maintaining were accounted for, we estimated a saving of £68 685.75 was performed by moving to a nurse-delivered model for ILR implants. Over 133 catheter laboratory and implanting physician hours were saved and utilized for other more complex procedures.

CONCLUSION

ILR implantation in the outpatient setting by suitably trained nurses is safe and leads to significant financial savings.

Recommendations on the use of innovative medical technologies in cardiology and cardiac surgery and solutions leading to increased availability for Polish patients

There is a great need for innovative technologies that will improve the health and quality of life (QoL) of Polish patients with cardiac problems. It is important that the safety and effectiveness of the technology are confirmed by scientific evidence on which guidelines and clinical recommendations are based. Scientific evidence for medical devices is also increasingly important for decision-making in finance approval from public funds. New technologies in cardiology and cardiac surgery contribute to improved patient QoL, increased treatment effectiveness and facilitated diagnosis. Hence, it is necessary to increase accessibility to such technologies, primarily through the development of clinical recommendations, and education of medical personnel in conjunction with public funding. The aim of this publication is to present the recommendations of leading experts in the field of cardiology and cardiosurgery, supported by clinical research results, regarding the use of the cited innovative medical technologies and solutions leading to their increased availability for Polish patients.

Use of a Pediatric Syncope Unit Improves Diagnosis and Lowers Costs: A Hospital-Based Experience

OBJECTIVES

To assess the effect of a dedicated pediatric syncope unit on the diagnostic and therapeutic management of children with suspected syncope. We also evaluated the effectiveness of the pediatric syncope unit model in decreasing unnecessary tests and hospitalizations, minimizing social costs, and improving diagnostic yield.

STUDY DESIGN

This single-center cohort observational, prospective study enrolled 2278 consecutive children referred to Bambino Gesù Children's Hospital from 2012 to 2017. Characteristics of the study population, number and type of admission examinations, and diagnostic findings before the pediatric syncope unit was implemented (2012-2013) and after the pediatric syncope unit was implemented (2014-2015 and 2016-2017) were compared.

RESULTS

The proportion of undefined syncope, number of unnecessary diagnostic tests performed, and number of hospital stay days decreased significantly (P < .0001), with an overall decrease in costs. A multivariable logistic regression analysis, adjusted for confounding variables (age, sex, number of diagnostic tests), the period after pediatric syncope unit (2016-2017) resulted as the best independent predictor of effectiveness for a defined diagnosis of syncope (P < .0001).

CONCLUSIONS

Pediatric syncope unit organization with fast-tracking access more appropriate diagnostic tests is effective in terms of accuracy of diagnostic yield and reduction of costs.

A single center experience on the clinical utility evaluation of an insertable cardiac monitor

BACKGROUND

The evaluation of insertable cardiac monitor (ICM) has been largely on the device performance and safety with only limited studies on the clinical utility. The aim of this study was to evaluate the clinical utility of ICM in patients with a variety of clinical presentations.

METHODS

A single-center retrospective study on the clinical utility, as measured by both expected and unexpected clinical useful ICM findings and the initiation of therapeutic interventions, was conducted.

RESULTS

Ninety-five consecutive patients (median age 68 years) received ICM Reveal LINQ™ for clinical indications of unexplained syncope (53), cryptogenic stroke (19), unexplained infrequent palpitations (14) and AF management (9). During a median follow-up of 414 days, the causes for unexplained syncope were arrhythmia-related (11.3%), arrhythmia-unrelated (32%) and undetermined (56.6%). Atrial fibrillation in patients with cryptogenic stroke was detected in 31.6% (6/19). The clinical utility occurrence was 48.4% with the expected and incidental (unexpected) clinical utility of 41% and 7.4% patients respectively. Of these, therapeutic interventions based on ICM diagnoses were initiated in 18.9% (18/95) of patients.

CONCLUSIONS

ICM (Reveal LINQ™) offers substantial expected and unexpected clinical utility in patients with a variety of clinical presentations. The causes of nearly one third of patients receiving ICM for unexplained syncope were unrelated to cardiac arrhythmia. Nearly one fifth of patients with newly diagnosed arrhythmia from ICM received therapeutic interventions.

Ambulatory diagnostic ECG monitoring for syncope and collapse: An assessment of clinical practice in the United States

INTRODUCTION

Diagnostic ambulatory electrocardiogram (AECG) monitoring is widely used for evaluating syncope and collapse, and practice guidelines provide recommendations regarding optimal AECG device selection. However, whether physicians utilize AECGs in accordance with the pertinent guidelines is unclear. This study assessed utilization of AECG monitoring systems for syncope and collapse diagnosis by physicians in the United States.

METHODS AND RESULTS

A quantitative survey was undertaken of physicians comprising multiple specialties (emergency department, n = 35; primary care, n = 35; hospitalists, n = 30; neurologists, n = 30; nonimplanting, n = 34, and implanting-cardiologists, n = 35). Depending on specialty, respondents reported that neural-reflex and orthostatic causes accounted for 17-23%, cardiac causes for 12-20%, and "neurological causes" (specifically psychogenic pseudo-syncope/pseudo-seizures and acute cerebrovascular conditions) for 7-12% of their syncope/collapse cases. The choice of AECG technology varied by specialty. Thus, despite patients having daily symptoms, 25% of respondents chose an AECG technology other than a Holter-type monitor. Conversely, when monitoring for infrequent events (e.g., less than monthly), 12-18% indicated that they would choose a 24- to 48-hour Holter, 20-34% would choose either a conventional event recorder or a mobile cardiac telemetry system, and only 53-65% would select an insertable cardiac monitor.

CONCLUSIONS

In evaluation of syncope/collapse, most U.S. clinicians across specialties use AECGs appropriately, but in a substantial minority there remains discordance between choice of AECG technology and guideline-based recommendations.

A Population-Based Cohort Study Evaluating Outcomes and Costs for Syncope Presentations to the Emergency Department

OBJECTIVES

This study sought to examine outcomes and costs of patients with syncope admitted and discharged from the emergency department (ED).

BACKGROUND

ED visits for syncope are common, yet the impact on health care utilization is relatively unknown.

METHODS

A total of 51,831 consecutive patients presented to the ED with a primary diagnosis of syncope (International Classification of Diseases-9 code 780.2 and International Classification of Diseases-10 code R55) in Alberta, Canada from 2006 to 2014. Outcomes included 30-day syncope ED and hospital readmissions; 30-day and 1-year mortality; and annual inpatient, outpatient, physician, and drug costs, cumulative.

RESULTS

Of adults presenting to the ED, 6.6% were hospitalized and discharged with a primary diagnosis of syncope (Cohort 1), 8.7% were hospitalized and discharged with a primary diagnosis other than syncope (Cohort 2), and 84.7% were discharged home with a syncope diagnosis (Cohort 3). The 30-day ED revisits for syncope varied from 1.2% (Cohort 2) to 2.4% (Cohort 1) (p < 0.001), and readmission rates were <1% among cohorts. Short- and long-term mortality rates were highest for Cohort 2 and lowest for Cohort 3 (30-day mortality: Cohort 1 of 1.2%, Cohort 2 of 5.2%, Cohort 3 of 0.4%; p < 0.001) (1-year mortality: Cohort 1 of 9.2%, Cohort 2 of 17.7%, Cohort 3 of 3.0%; p < 0.001). Total cost of syncope presentations was $530.6 million (Cohort 1: $75.3 million; $29,519/patient, Cohort 2: $138.1 million; $42,042/patient, Cohort 3: $317.3 million; $9,963/patient; p<0.001).

CONCLUSIONS

Most patients with syncope presenting to the ED were discharged and had a favorable prognosis but overall costs were high compared with patients hospitalized. Further research is needed for cost-saving strategies across all cohorts.

Current rare indications and future directions for implantable loop recorders

The scope of application for implantable loop recorders has shifted away from the evaluation of unclear palpitations and syncope episodes to more complex conditions. This article focuses on rare indications of growing importance such as rhythm monitoring after ablation of atrial fibrillation or after cryptogenic stroke. Furthermore, forthcoming applications in various clinical settings are described, e. g., arrhythmia detection after myocardial infarction, after catheter-based valve interventions, in heart failure, and in cardiomyopathies. Enhancement of the capabilities of implantable loop recorders could broaden their fields of use.

Cost Analysis of Patients Referred for Inherited Heart Rhythm Disorder Evaluation

BACKGROUND

Inherited heart rhythm disorders (IHRDs) are complex and uncommon arrhythmogenic conditions that can lead to sudden unexpected death in seemingly healthy individuals. Multidisciplinary programs can assist in the diagnostic testing of potentially affected individuals and their family members.

METHODS

Patients evaluated in a specialized adult and pediatric IHRD clinic between April 2013 and February 2015 were characterized. The total costs per evaluation and diagnosis were calculated. Patients were divided according to referral indication (primary referral or family member).

RESULTS

A total of 618 patients were evaluated (age 36 ± 21 years; 52% male), of which 274 (44%) were primary referrals and 344 (56%) were family members referred for cascade screening. Overall, 47% had at least 1 follow-up visit. Patients had a median of 3 tests; primary referrals required more tests (4 vs 2; P < 0.01). The median cost per patient was $1340 CAD. Evaluation of the primary referrals was costlier than family members ($3096 vs $983; P < 0.01). A definite or probable diagnosis was determined in 464 patients (77%), with no difference according to patient type (P = 0.18). The total cost per diagnosis was $4021 in primary referrals compared with $1277 in family members (P < 0.01).

CONCLUSIONS

Clinical evaluation of patients with suspected IHRD results in a high diagnostic yield and costs aligned with other complex disorders involving multidisciplinary clinics. Evaluation costs are expectedly higher in primary referrals compared with targeted family screening.

Maintaining Accurate Long-Term Sensing Ability Despite Significant Size Reduction of Implantable Cardiac Monitors

BACKGROUND

The Reveal LINQ™ implantable cardiac monitor (ICM; Medtronic, Minneapolis, MN, USA) is obviously smaller than its precursor (the Reveal XT™), but little is known about its long-term safety. Here, we investigated the long-term R-wave sensing reliability of the Reveal LINQ™ ICM.

METHODS

We analyzed the sensing quality of the Reveal LINQ™ ICM over time between March 2014 and January 2015.

RESULTS

A total of 30 patients underwent Reveal LINQ™ implantation. The main reason for implantation was unexplained syncope (60%). We evaluated a total of 305.8 patient-months (median, 10.7 months) of R-wave sensing quality. A comparison of baseline and follow-up R-wave sensing values revealed no difference (0.401 mV ± 0.244 mV vs 0.447 mV ± 0.323 mV; P = 0.225).

CONCLUSIONS

The consistent detection of events is an important safety feature of an ICM and linked to secure R-wave sensing. Despite the noticeable size reduction, the Reveal LINQ™ ICM retains reliable sensing quality over time.

[Implantable loop recorders in the diagnosis of syncope]

In syncope patients, it is essential to make the right diagnosis with respect to underlying etiology. Cardiac (arrhythmic and structural) syncopal episodes carry untoward prognostic implication compared with reflex syncope. While rhythm-symptom correlation of a spontaneous syncopal episode is key to making the correct diagnosis, in case of unclear syncope the early implantation of a loop recorder leads to faster, more efficacious, and more cost-effective diagnosis. This review article summarizes the current data regarding diagnostic accuracy and clinical role of implantable loop recorders. It outlines the superiority of loop recorders in the management of unclear syncope according to present knowledge.

An Engineering Perspective of External Cardiac Loop Recorder: A Systematic Review

External cardiac loop recorder (ELR) is a kind of ECG monitoring system that records cardiac activities of a subject continuously for a long time. When the heart palpitations are not the frequent and nonspecific character, it is difficult to diagnose the disease. In such a case, ELR is used for long-term monitoring of heart signal of the patient. But the cost of ELR is very high. Therefore, it is not prominently available in developing countries like India. Since the design of ELR includes the ECG electrodes, instrumentation amplifier, analog to digital converter, and signal processing unit, a comparative review of each part of the ELR is presented in this paper in order to design a cost effective, low power, and compact kind of ELR. This review will also give different choices available for selecting and designing each part of the ELR system. Finally, the review will suggest the better choice for designing a cost effective external cardiac loop recorder that helps to make it available even for rural people in India.

The Evaluation of Syncope in a Predominantly Black Population: Focus on Neuroimaging

Background:

Current guidelines do not support the routine use of computed tomography (CT) scan of the head in the diagnostic workup of syncope. There is a lack of research to support whether these guidelines apply to the Black population.

Aims:

This study aims to evaluate the yield of neuroimaging in the evaluation of Syncope in a predominantly Black patient population and to test whether current guidelines based on studies conducted in other populations hold true in this group.

Material and Methods:

A retrospective review of records of 151 patients admitted to a University Hospital with Syncope from 2011 to 2014 was performed. Data collected include CT head, magnetic resonance imaging of the brain, magnetic resonance angiogram, electroencephalogram, and orthostatic vital signs. Demographic data, admitting service, and comorbid conditions were identified. Syncope was classified as cardiogenic, orthostatic, vasovagal, situational, or undetermined. Statistical analysis was performed to determine which diagnostic tools were useful in identifying the potential causes of syncope. Data analysis was conducted using the Statistical Analysis System software 9.3 (SAS Institute, Cary, NC) and Statistical Analysis and Graphics (NCSS 9.0.7, Kaysville, UT).

Results:

One hundred and twenty eight (84.8%) of the patients were Black. The average age was 56.62 ± 18.78 standard deviation and 68.2% (103) were female. One hundred and fourteen patients (75.5%) had a CT brain. Five out of 114 patients had an acute abnormality on CT (4.4%). Only 1 of these 5 patients had an abnormality that was related to syncope. CT brain (P = 0.978) was not found to be predictive of underlying etiology of syncope despite high frequency of use.

Conclusions:

CT head was not useful in determining the etiology of syncope in a predominantly Black population. Current guidelines and studies conducted in other populations have detected similar findings.

Management of Postural Tachycardia Syndrome, Inappropriate Sinus Tachycardia and Vasovagal Syncope

Postural tachycardia syndrome (POTS), inappropriate sinus tachycardia (IST) and vasovagal syncope (VVS) are relatively common clinical syndromes that are seen by physicians in several disciplines. They are often not well recognised and are poorly understood by physicians, are associated with significant morbidity and cause significant frustration for both patients and their physicians. The 2015 Heart Rhythm Society Expert Consensus Statement on the Diagnosis and Treatment of Postural Tachycardia Syndrome, Inappropriate Sinus Tachycardia and Vasovagal Syncope provides physicians with an introduction to these disorders and initial recommendations on their investigation and treatment. Here we summarise the consensus statement to help physicians in the management of patients with these frequently distressing problems.

Implantable loop recorder versus conventional diagnostic workup for unexplained recurrent syncope

BACKGROUND

The most recent syncope guideline recommends that implantable loop recorders (ILRs) are implanted in the early phase of evaluation of people with recurrent syncope of uncertain origin in the absence of high-risk criteria, and in high-risk patients after a negative evaluation. Observational and case-control studies have shown that loop recorders lead to earlier diagnosis and reduce the rate of unexplained syncopes, justifying their use in clinical practice. However, only randomised clinical trials with an emphasis on a primary outcome of specific ILR-guided diagnosis and therapy, rather than simply electrocardiogram (ECG) diagnosis, might change clinical practice.

OBJECTIVES

To assess the incidence of mortality, quality of life, adverse events and costs of ILRs versus conventional diagnostic workup in people with unexplained syncope.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 3, 2015), MEDLINE, EMBASE, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) Search Portal in April 2015. No language restriction was applied.

SELECTION CRITERIA

We included all randomised controlled trials of adult participants (i.e. ≥ 18 years old) with a diagnosis of unexplained syncope comparing ILR with standard diagnostic workup.

DATA COLLECTION AND ANALYSIS

Two independent review authors screened titles and abstracts of all potential studies we identified as a result of the literature search, extracted study characteristics and outcome data from included studies and assessed risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. We contacted authors of trials for missing data. We analysed dichotomous data (all-cause mortality and aetiologic diagnosis) as risk ratios (RR) with 95% confidence intervals (CI). We used the Chi(2) test to assess statistical heterogeneity (with P < 0.1) and the I² statistic to measure heterogeneity among the trials. We created a 'Summary of findings' table using the five GRADE considerations (study limitations, consistency of effect, imprecision, indirectness and publication bias) to assess the quality of a body of evidence as it relates to the studies which contribute data to the meta-analyses for the prespecified outcomes.

MAIN RESULTS

We included four trials involving a total of 579 participants. With the limitation that only two studies reported data on mortality and none of them had considered death as a primary endpoint, the meta-analysis showed no evidence of a difference in the risk of long-term mortality between participants who received ILR and those who were managed conventionally at follow-up (RR 0.97, 95% CI 0.41 to 2.30; participants = 255; studies = 2; very low quality evidence) with no evidence of heterogeneity. No data on short term mortality were available. Two studies reported data on adverse events after ILR implant. Due to the lack of data on adverse events in one of the studies' arms, a formal meta-analysis was not performed for this outcome.Data from two trials seemed to show no difference in quality of life, although this finding was not supported by a formal analysis due to the differences in both the scores used and the way the data were reported. Data from two studies seemed to show a trend towards a reduction in syncope relapses after diagnosis in participants implanted with ILR. Cost analyses from two studies showed higher overall mean costs in the ILR group, if the costs incurred by the ILR implant were counted. The mean cost per diagnosis and the mean cost per arrhythmic diagnosis were lower for participants randomised to ILR implant.Participants who underwent ILR implantation experienced higher rates of diagnosis (RR (in favour of ILR) 0.61, 95% CI 0.54 to 0.68; participants = 579; studies = 4; moderate quality evidence), as compared to participants in the standard assessment group, with no evidence of heterogeneity.

AUTHORS' CONCLUSIONS

Our systematic review shows that there is no evidence that an ILR-based diagnostic strategy reduces long-term mortality as compared to a standard diagnostic assessment (very low quality evidence). No data were available for short-term all-cause mortality. Moderate quality evidence shows that an ILR-based diagnostic strategy increases the rate of aetiologic diagnosis as compared to a standard diagnostic pathway. No conclusive data were available on the other end-points analysed.Further trials evaluating the effect of ILRs in the diagnostic strategy of people with recurrent unexplained syncope are warranted. Future research should focus on the assessment of the ability of ILRs to change clinically relevant outcomes, such as quality of life, syncope relapse and costs.

Implantable Loop Recorder – A Good Opportunity to Diagnose Unexplained Syncope

Implantable loop recorder (ILR) is a method in cardiology, which is used for the diagnosis of unexplained syncope in patients who were not treated successfully using standard methods. Implantable loop recorder is a diagnostic device that is surgically implanted under the skin of the chest area. This device does not have the endovenous implantation of electrodes; instead, electrodes are attached to the machine housing. The device records the heart rhythm continuously, up to 14 months, and stores data outside the activator whenever symptoms appear, or by the automatic activation of the predefined program for bradycardia, asystole, and tachycardia. The aim of this paper was to describe the method for the detection of cardiac syncope with the use of implantable loop recorder.

Insertable cardiac monitors in the diagnosis of syncope and the detection of atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Insertable or implantable cardiac monitors (ICMs) continuously monitor the heart rhythm and record irregularities over 3 years, enabling the diagnosis of infrequent rhythm abnormalities associated with syncope and stroke. The enhanced recognition capabilities of recent ICM models are able to accurately detect atrial fibrillation (AF) and have led to new applications of ICMs for the detection and monitoring of AF.

METHODS AND RESULTS

Based on a systematic literature search, two indications were identified for ICMs for which considerable evidence, including randomized studies, exists: diagnosing the underlying cardiac cause of unexplained recurrent syncope and detecting AF in patients after cryptogenic stroke (CS). Three randomized controlled trials (RCTs) were identified that compared the effectiveness of ICMs in diagnosing patients with unexplained syncope (n = 556) to standard of care. A meta-analysis was conducted in order to generate an overall effect size and confidence interval of the diagnostic yield of ICMs versus conventional monitoring. In the indication CS, one RCT and five observational studies were included in order to assess the performance of ICMs in diagnosing patients with AF (n = 1129). Based on these studies, there is strong evidence that ICMs provide a higher diagnostic yield for detecting arrhythmias in patients with unexplained syncope and for detection of AF in patients after CS compared to conventional monitoring.

CONCLUSIONS

Prolonged monitoring with ICMs is an effective tool for diagnosing the underlying cardiac cause of unexplained syncope and for detecting AF in patients with CS. In all RCTs, ICMs have a superior diagnostic yield compared to conventional monitoring.

Safety Profile of a Miniaturized Insertable Cardiac Monitor: Results from Two Prospective Trials

BACKGROUND

Insertable cardiac monitors (ICMs) are used to continuously monitor the patient's electrocardiogram. In response to patient activation or based on automated device algorithms, arrhythmia episodes are stored and automatically transmitted daily to the clinician. Thus, ICMs can be used to diagnose arrhythmias in at-risk patients and in those with symptoms potentially attributable to arrhythmias. The ICM described in this report has undergone a dramatic change in size and method of insertion.

METHODS

To evaluate the safety profile of the ICM procedure, we analyzed procedure-related adverse events (AEs) from two separate trials: A controlled, nonrandomized multicenter study (Reveal LINQ(TM) Usability study) and a multicenter registry (Reveal LINQ(TM) Registry) evaluating real-world experience. For the Registry we reported all procedure-related AEs upon occurrence, whereas for the Usability study, we reported events occurring during the first month of follow-up.

RESULTS

The Usability study enrolled 151 patients (age 56.6 ± 12.1 years; male 67%) at 16 centers; during follow-up, an infection was observed in 1.3% patients and a procedure-related serious AE (SAE) in 0.7% patients. The Registry enrolled 122 patients (age 61.0 ± 17.8 years; male 47%) at seven centers; during follow-up, an infection was observed in 1.6% patients and a procedure-related SAE in 1.6% patients.

CONCLUSIONS

The cumulative experience from a controlled clinical trial and a "real-world" registry demonstrate that the new ICM can be inserted with very low incidence of AEs.

Syncope: the emergency department and beyond

Syncope is a common problem encountered by both emergency and internal medicine physicians. This review focuses on not only the assessment, risk stratification and management of the syncope patient, but also the latest thinking on diagnostic testing including more novel tools such as biomarkers and ambulatory patch monitor recording.

The Role of the Syncope Management Unit

Syncope is a common symptom, experienced by 15% of persons less than 18 years old and up to 23% of elderly nursing home residents, so it is important to consider optimizing strategies for the management of these patients. The strategy selected will inevitably differ from place to place. However, an organized structure offers more cost-effective care. This article discusses possible health care delivery models for syncope management and reviews the current status of the organization of syncope care, to show the value of a multidisciplinary approach to the organized management of patients with syncope.

Value of Ambulatory Electrocardiographic Monitoring in Syncope

Implantable loop recorders (ILRs) continuously monitor electrocardiographic signals and perform real-time analysis of heart rhythm for up to 36 months. ILRs are used to evaluate transitory loss of consciousness from possible arrhythmic origin, particularly unexplained syncope, and to evaluate difficult cases of epilepsy and unexplained falls, although current indications for their application in these areas are less clearly defined. This article analyzes the current indications for ILRs according the European Society of Cardiology guidelines on the management of syncope and the European Heart Rhythm Association guidelines on the use of implantable and external electrocardiogram loop recorders, and their limitations.

[Role of implantable loop recorder in the clinical diagnosis of syncope: results of the introduction of an effective diagnostic tool]

INTRODUCTION

Extension of electrocardiographic monitoring via loop recorder implantation may increase the diagnostic yield of syncope work-up.

AIM

In this retrospective observational study, the authors wanted to evaluate the diagnostic performance of implantable loop recorder in the everyday clinical practice.

METHOD

The authors analyzed the electronically stored data of all patients who underwent loop recorder implantation between 2005 and 2014 in their cardiology department because of recurrent syncope of undetermined origin.

RESULTS

There were 52 loop recorder implantations within the study period. During the 167 (± 136) days of monitoring, 36 (69.2%) diagnostic events occurred. In two-thirds of events, (46.2% of all monitored patients) a specific arrhythmia diagnosis was reached, allowing definitive treatment in these cases. In this selected population, there was no correlation between age, presence of known high-risk predictors, or accompanying trauma, and the mechanism of syncope.

CONCLUSIONS

The high diagnostic rate of implantable loop recorder in the everyday clinical practice is in accordance with the findings in prospective clinical studies. This observation supports the early application of loop recorder in the diagnostic algorithm of syncope.

Single center experience in Japanese patients with syncope

BACKGROUND AND PURPOSE

The present diagnostic method and features of syncope in Japan are unclear. Implantable loop recorder (ILR) and head-up tilt tests have recently become available for diagnosing syncope. The examination method and rates of diagnosing syncope may vary. This study aimed to clarify the present diagnostic method and features of syncope in a single Japanese medical center.

METHODS AND RESULTS

We retrospectively reviewed the medical records of consecutive patients who were seen at our hospital from January 1, 2009, to December 31, 2012. A total of 547 patients (328 men, 60.4±21.5 years) with syncope were seen at our hospital. Reflex syncope was diagnosed in 29.1% of the cases, orthostatic hypotension in 11.7%, cardiac syncope in 34.0%, and unexplained syncope in 23.9% by initial and early evaluations. The number of patients with situational syncope and orthostatic hypotension that could be diagnosed in the initial evaluation of the first examination was significantly greater than that in subsequent evaluations. Forty-three percent of the unexplained syncope patients received an ILR. The consent rate for ILR implantations in the unexplained syncope patients with a suspected arrhythmia nature was 53.1%. The cumulative ILR diagnostic rates were 47% and 65% at 1 and 2 years after the ILR implantation, respectively. The estimated ILR diagnostic rates were significantly greater than that for conventional test without using an ILR. When patients with unexplained syncope could be diagnosed, the recurrent symptoms were greatly reduced.

CONCLUSIONS

Syncope is induced by various causes in Japan. It is important that we understand the characteristics of each syncope cause. The consent rate for implanting an ILR in appropriate unexplained syncope patients is low. We need to educate these patients about the importance of making a diagnosis of syncope.