Use Of Implantable Loop Recorders Research Articles

Initial experience with a virtual atrial fibrillation clinic after pulmonary vein isolation

Abstract Introduction To detect recurrent atrial fibrillation (AF), a variety of methods are used, ranging from incidental electrocardiogram to rhythm monitoring with implantable loop recorders (ILRs). In clinical practice, routine use of ILRs is not feasible due to cost. Repeated (week)-Holters cause a considerable burden, both on patients and hospitals, and moreover are inadequate for detecting recurrent AF. Purpose To investigate whether remote monitoring (RM) is feasible in patients with AF after pulmonary vein isolation. Methods We set up a virtual AF clinic. Patients were equipped with a photopletysmography (PPG) application and asked to perform a recording when symptomatic. Recordings uploaded to the Hospital Electronic Patient Dossier and monitored by dedicated eNurses. The number of hospital contacts, hospital visits, electrocardiograms and Holter recordings were noted. Patient satisfaction and quality of life was measured by (validated) questionnaires. Comparisons were made with a historic control group from Jan-March 2019 with a traditional follow up of outpatient visits, electrocardiograms and Holters. Results 157 patients were studied, 78 in the RM group and 79 in the control group. Mean age was 63 ± 10 years, 64% male. AF was paroxysmal in 68% of patients. Follow-up was 1 year and completed in all patients. In the RM group, patients performed 16±29 recordings/year. AF was detected in 37 (47%) patients on RM. While more planned remote contacts were performed in the RM group, significantly less planned and unplanned outpatient clinic visits, AF-related hospital admissions, and Holters took place. Patients report a high satisfaction with this form of remote monitoring. Conclusions A virtual AF clinic is feasible. When asked to record when symptomatic, patients perform few measurements. Compared to patients with a traditional follow-up, patients on PPG-based RM need fewer hospital visits and admissions, and undergo fewer Holters. Patient satisfaction with RM is high.

Arrhythmia detection using an implantable loop recorder after a negative electrophysiology study in Brugada syndrome: Observations from a multicenter international registry

BackgroundRisk stratification in Brugada syndrome (BrS) remains controversial. In this respect, the role of the electrophysiology study (EPS) has been a subject of debate. In some centers, it is common practice to use an implantable loop recorder (ILR) after a negative EPS to help in risk stratification. However, the diagnostic value of this approach has never been specifically addressed. ObjectiveThe aim of this study was to describe the baseline characteristics and the main findings of a diagnostic workup strategy with an ILR after a negative EPS in BrS. MethodsWe conducted a retrospective international registry including patients with BrS and negative EPS (ie, noninducible ventricular tachycardia or ventricular fibrillation) before ILR monitoring. ResultsThe study included 65 patients from 8 referral hospitals in The Netherlands, Spain, and the United Kingdom (mean age, 39 ± 16 years; 72% male). The main indication for ILR monitoring was unexplained syncope/presyncope (66.2%). During a median follow-up of 39.0 months (Q1 25.0–Q3 47.6 months), 18 patients (27.7%) experienced 21 arrhythmic events (AEs). None of the patients died during follow-up. Bradyarrhythmias were the most common finding (47.6%), followed by atrial tachyarrhythmias (38.1%). Only 3 patients presented with ventricular arrhythmias. AEs were considered incidental in 12 patients (66.7%). In 11 patients (61.1%), AEs led to specific changes in treatment. ConclusionThe use of ILR after a negative EPS in BrS is a safe strategy that reflected the high negative predictive value of EPS for ventricular arrhythmia in this syndrome. In addition, it allowed the detection of AEs in a significant proportion of patients, with therapeutic implications in most of them.

Implantable loop recorder monitoring in inherited cardiomyopathies: yield of clinically relevant arrhythmias

Abstract Background Implantable loop recorders (ILRs) are a minimally invasive tool for the diagnosis of arrhythmias in patients with unexplained syncope or asymptomatic arrhythmias. Their use in patients with inherited arrhythmia syndromes has been recommended in the recent 2022 ESC Guidelines (1). However, the clinical utility of ILRs in patients with inherited cardiomyopathies remains unexplored. Purpose The purpose of this study was to evaluate the yield of ILR monitoring in detecting clinically relevant events in a single cohort of patients with inherited cardiomyopathies. Methods We prospectively collected demographic, clinical, and follow-up data from patients with inherited cardiomyopathies (Arrhythmogenic Cardiomyopathy, ACM; Hypertrophic Cardiomyopathy, HCM; Dilated Cardiomyopathy, DCM; Left Ventricular Non-Compaction, LVNC) who were implanted with an ILR and were followed with telemedicine. The primary endpoint was a clinically significant event recorded with the ILR that required an update to an implantable cardioverter defibrillator (ICD). Results The study cohort included 53 consecutive patients (55% males; mean age at ILR implantation 35±14 years) with inherited cardiomyopathies: 33/53 (62%) with ACM, 9/53 (17%) with HCM, 7/53 (13%) LVNC, 4/33 (8%) DCM. None of the patients implanted had previously experienced life-threatening arrhythmias. During a median follow-up of 2.6 years (IQR 1.4-3.7 years) after ILR implantation, clinically relevant arrhythmic events were documented in 9/53 (17%) of patients. Specifically, sustained or non-sustained ventricular tachycardia episodes were detected in 8 patients (5 with ACM, 2 with LVNC, 1 with LMNA-related DCM), whereas one patient with HCM showed symptomatic pauses > 3 seconds due to sick sinus syndrome. In all cases, the detection of such episodes led to the upgrade to ICD implantation. Conclusions ILR monitoring of patients with inherited cardiomyopathies identified clinically relevant events in almost one-fifth of patients, suggesting that the use of ILR may substantially improve the management of these patients. Figure 1. Representative example of clinically actionable event detected by implantable loop recorder (ILR) in a patient with inherited cardiomyopathy. The patient, a 19-year-old male with a definitive diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) and a pathogenic PKP2 truncating variant, presented with palpitations and vertigo during physical exertion one year after the implantation of an ILR. ILR monitoring documented a rapid tachycardia with a mean frequency of 250 bpm lasting 3 minutes, prompting an indication for an implantable cardioverter defibrillator (ICD).Figure 1.

Abstract 15925: Comparative Mortality, Safety, and Cost Among Stroke Patients Who Received Implantable Loop Records Compared to Continuous External Cardiac Monitors

Background: Implantable loop recorders (ILR) are increasingly used to screen for atrial fibrillation (AF) among patients with stroke, but real-world outcomes are lacking. Goal: To determine comparative effectiveness, safety, and costs of ILR compared with continuous external monitors (CEM) and Holter monitors in a real-world setting of patients with stroke. Methods: This retrospective cohort analysis used the Optum Labs Data Warehouse, which contains longitudinal, de-identified administrative claims. The cohort included patients with recent stroke who received cardiac monitoring from 1/1/2016 - 6/30/2021, comparing those with ILR to those with CEM (>48 hours to 30 days) or Holter (≤48 hours). Eligibility criteria included: ischemic stroke during 6 month baseline; continuous enrollment with medical and pharmacy coverage; no evidence of pacemaker, implantable cardioverter-defibrillator, AF, left atrial appendage ablation, or oral anticoagulants. The primary outcome was 12-month all-cause mortality, secondary outcomes included new diagnosis of AF + initiation of anticoagulants, hemorrhagic stroke, and total and device-related costs. Final analyses were adjusted for CHA 2 DS 2 -VASc score. Results: Among 48,801 individuals, 18.9% received ILR, 59.5% CEM, and 21.6% Holter. Groups had similar demographics and comorbidities (Table). Compared to those with CEM, the ILR group had higher odds of a new diagnosis of AF plus initiation of anticoagulants (OR 2.27; (95% CI 2.09, 2.48)), and hemorrhagic stroke (OR of 1.60 (95% CI 1.34, 1.93)). There was no difference in mortality. Unadjusted direct medical cost of monitoring was substantially higher in the ILR group ($13,975) compared to CEM ($449) and Holter ($149). Conclusions: Although the use of ILRs was associated with increased detection and treatment for AF, there was no impact on all-cause mortality. ILR was associated with increased hemorrhagic stroke and higher costs.

Identification of acute ST-elevation myocardial infarction via remote implantable loop recorder monitor

The indications for the use of implantable loop recorders include the evaluation of unexplained palpitations and syncope, embolic stroke of undetermined source, dizziness and lightheadedness presumed to be due to arrhythmogenic etiology, and for atrial fibrillation to guide antiarrhythmic drug therapy or catheter ablation efficacy. Long-term monitoring is especially beneficial if symptoms occur sporadically or are asymptomatic in nature. This is the first case to our knowledge of an acute ST-elevation myocardial infarction which was identified from remote monitoring of an implantable loop recorder through a device clinic.

Detection of atrial fibrillation using an implantable loop recorder in patients with previous cryptogenic stroke: the SPIDER-AF registry (Stroke Prevention by Increasing DEtection Rates of Atrial Fibrillation).

The use of implantable loop recorder (ILR) to detect atrial fibrillation (AF) in patients with a history of cryptogenic stroke (CS) has seldom been investigated in "real-world" settings. This study aimed to present the results of the Stroke Prevention by Increasing DEtection Rates of Atrial Fibrillation (SPIDER-AF) registry. SPIDER is a multicentric, observational registry, including 35 facilities all over Germany. It enrolled outpatients without AF history and with CS before ILR implantation. We included 500 patients (mean age 63.1 ± 12.7years), 304 (60.8%) were males, with previous stroke (72.6%) and TIA (27.4%). After inclusion, all were followed for at least 12months. AF was detected in 133(26.8%), 25.3% of patients with previous stroke and 29.9% with TIA (p = 0.30). AF was detected after a median of 121.5days (IQR 40.5-223.0). AF was primarily paroxysmal (95.7% after stroke, 100% after TIA). In 19.5% (n = 26) anticoagulation was not administered after AF detection. Mean CHA2DS2-VASc score (OR 1.22; CI 1.01-1.49; p = 0.037) and age > 70years (OR 0.41; CI 0.19-0.88; p = 0.0020) correlated with AF. Repeat cerebrovascular events at follow-up (28; 5.6%) correlated with AF (OR = 2.17; CI 1.00-4.72; p = 0.049). AF (p = 0.91) and recurrent events (p = 0.43) occurred similarly in females and males. In the context of cryptogenic strokes ILRs are a valuable tool for early detection of AF. In a real-world scenario, the anticoagulation therapy remains inadequate despite diagnosed AF in a relevant subset of patients requiring optimization of patient management.

Rationale and design of the NEO-NORMAL-AF study examination of the usefulness of implantable loop recorder for arrhythmia detection including atrial fibrillation in heart failure with non-reduced ejection fraction cases: a pilot study

IntroductionThe incidence of arrhythmia in heart failure with non-reduced ejection fraction (HFnon-rEF) in patients who have a history of hospitalisation is unclear. The aim of this study is to investigate...

The Role of Implantable Loop Recorder in Patients with Cryptogenic Stroke

Objective: The objective of this study was to provide data on implantable loop recorder (ILR)-based atrial fibrillation (AF) rates, recurrent stroke rates, and predictors of AF in patients with cryptogenic stroke (CS) after 1, 6, 12, 24, and 36 months of follow-up. Methods: We searched MEDLINE/PubMed, Cochrane Central Register of Controlled Trials, EMBASE, Web of Science, and reference lists of retrieved reports, which were published by April 30, 2023, which was the date of our last search. We utilized random-effects meta-analysis for detection rates, and meta-regression analysis, t-test (for normally distributed variables), and Mann-Whitney (for skewed variables) for predictor factors. Results: Thirteen studies were analyzed, which included data from 3,377 patients with CS or embolic stroke of undetermined source. The ILR-based AF rates in patients with CS were 4.73% (95% confidence interval [CI] 3.91–5.71) at 1 month, 13.45% (95% CI 12.19–14.81) at 6 months, 17.5% (95% CI 16.25–18.82) at 12 months, 20.69% (95% CI 19–22.49) at 24 months, and 25.98% (95% CI 23.21–28.58) at 36 months. Age and CHA2DS2-VASc score were positively associated with AF detection. Specifically, the mean difference of age and CHA2DS2-VASc score in the group with AF versus the group without AF was 7.47 (95% CI 4.58–10.36, P < 0.001) and 0.75 (95% CI 0.22–1.28, P = 0.01), respectively. Finally, AF detection was positively associated with recurrent strokes with an estimated risk ratio of 1.27 (95% CI 0.69–2.31). Conclusions: There is a correlation between AF detection rate and ILR monitoring duration. One out of eight patients was diagnosed with AF after 6 months of follow-up and about one quarter after 3 years. Our results demonstrate the critical use of ILRs, especially in older patients, and in patients with high CHA2DS2-VASc scores.

Role of the implantable loop recorder in clinical practice: insights on indications, diagnostic yield and therapeutic implications from a single, high volume, tertiary care centre experience

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Besides the established class I indication for the evaluation of patients with recurrent syncope of uncertain origin, implantable loop recorders (ILRs) have been increasingly used for other diagnostic purposes (e.g. detection of atrial fibrillation (AF) following cryptogenic stroke). Purpose To describe the main indications to ILR and to investigate procedural parameters, outcomes and diagnostic yield of ILR in a single, high-volume tertiary care centre. Methods All patients undergoing ILR implantation between November 2007 and April 2022 were consecutively enrolled in this study. Clinical characteristics of patients, procedural data and outcomes were collected. The indications to ILR implantation were divided into four categories: 1) AF detection in patients with recent cryptogenic stroke or peripheral thromboembolism [CRYSP], 2) recurrent syncope of uncertain origin [RSUO], 3) monitoring of ventricular arrhythmic events [VAE] in patients with predisposing cardiomyopathy/channelopathy, 4) monitoring of AF burden or relapse [AFB]. The main endpoint of the study was the diagnostic yield (number of definitive diagnoses made) and the time to diagnosis following ILR implantation. The occurrence of acute or subacute complications was used as a secondary safety endpoint. Results Overall, 1442 patients underwent ILR implantation (mean age 65 years, 43% female). The two main indications to ILR were AF detection following CRYSP and RSUO (42% and 34% of all implantations respectively, table 1). The commonest site of implantation was the left parasternal position (902 patients, 63%), median procedural time was 20 minutes (IQR 15-25). During a median follow-up of 397 days (134-1094), infections requiring ILR extraction or pocket revision occurred in 13 patients (0.9%). A definitive diagnosis was achieved in 500 (35%) patients after a median time of 206 days (IQR 60-533) [table 1 shows details and action taken following diagnosis for each indication subgroup]. At multivariable analysis, age and PR interval duration were significantly associated with the need for PM/ICD implantation among patients receiving ILR for RSUO whilst age was associated with AF detection among those with CRYSP (table 2). Conclusions In this cohort of patients use of ILR was associated with a good diagnostic yield regardless of the initial indication, triggered timely therapeutic actions and was overall safe.

PO-03-083 REAL-WORLD PERFORMANCE AND AGREEMENT RATES WITH HEALTHCARE PROFESSIONALS OF A NOVEL AI ALGORITHM RECLASSIFYING ILR EPISODES

The use of implantable Loop Recorders (ILRs) is increasing rapidly but generates a high workload, challenging timely adjudication of transmissions. This burden is aggravated by excessive false positive alerts. A novel artificial intelligence (AI)-based algorithm has been developed to reclassify ILR episodes aiming to decrease false positive rate by 80% while maintaining 99% sensitivity. To evaluate the performance of the algorithm in real-life conditions. 2,269 Medtronic Reveal LINQ ILR patients were enrolled from European medical centers from June to October 202. Using a cloud based remote monitoring platform, all episodes detected as “Abnormal” by ILRs were re-diagnosed by the AI algorithm. Healthcare professionals (HCPs) monitoring their patients on this platform could review the diagnosis indicated by the algorithm but, if necessary, attribute a new diagnosis to any episode. The positive predictive value (PPV) and negative predictive value (NPV) of the algorithm detecting “Abnormal” episodes were evaluated by comparing AI algorithm classification with healthcare professionals’ diagnoses, excluding uncertain diagnoses (artifact, lead noise, atrial and ventricular monitoring). Among 27,158 “Abnormal” LINQ episodes analyzed by the AI algorithm and checked by HCPs, 12,065 (44.4%) were diagnosed as “Normal Rhythm” by the algorithm. HCPs submitted a “certain” diagnosis on 2,683 of these episodes, among which 2,657 were “Normal Rhythm”, resulting in a NPV of 99.0%. The other 15,093 (55,6%) “Abnormal” diagnoses were confirmed by the AI algorithm. HCPs submitted a certain diagnosis on 2,351 of these episodes, among which 1,832 were “Abnormal”, resulting in a PPV of 77.9%. In this real-world study, the AI algorithm re-diagnosed 43.1% of LINQ detected episodes as “Normal Rhythm”. In addition, the AI algorithm showed good agreement rates with the HCPs reviewing the same episodes, with a 99.0% NPV and a 78.2% PPV.

A NOVEL AI ALGORITHM APPLIED TO ILR TRANSMISSIONS: PERFORMANCE AND AGREEMENT RATES WITH HEALTHCARE PROFESSIONALS

BackgroundThe use of implantable Loop Recorders (ILRs) is increasing rapidly but generates a high workload for timely adjudication of transmissions. This burden is aggravated by excessive false positive alerts. We developed a novel artificial intelligence (AI)-based algorithm to reclassify ILR episodes aiming to decrease False Positive rate by 80% while maintaining 99% sensitivity.ObjectiveTo evaluate the performance of the algorithm in real-life conditions.MethodsMedtronic Reveal LINQ ILR patients were enrolled from 40 European medical centers. Using a cloud based remote monitoring platform, all episodes detected as “Abnormal” by ILRs were re-diagnosed by the AI algorithm. Healthcare professionals (HCPs) monitoring their patients on this platform could review the diagnosis suggested by the algorithm and then attribute a new diagnosis to any episode. The positive predictive value (PPV) and negative predictive value (NPV) of the algorithm detecting “Abnormal” episodes were evaluated with healthcare professionals’ diagnoses, excluding uncertain diagnoses (artifact, lead noise, atrial and ventricular monitoring).ResultsAmong 10,296 “Abnormal” LINQ episodes analyzed by the AI algorithm and checked by HCPs, 4,442 (43.1%) were diagnosed as “Normal Rhythm” by the algorithm. HCPs submitted a certain diagnosis on 772 of these episodes, among which 750 were “Normal Rhythm”, resulting in a NPV of 97.1%. The other 5,854 (56.9%) “Abnormal” diagnoses were confirmed by the AI algorithm. HCPs submitted a certain diagnosis on 834 of these episodes, among which 773 were “Abnormal”, resulting in a PPV of 92.7%.Conclusion BackgroundThe use of implantable Loop Recorders (ILRs) is increasing rapidly but generates a high workload for timely adjudication of transmissions. This burden is aggravated by excessive false positive alerts. We developed a novel artificial intelligence (AI)-based algorithm to reclassify ILR episodes aiming to decrease False Positive rate by 80% while maintaining 99% sensitivity. The use of implantable Loop Recorders (ILRs) is increasing rapidly but generates a high workload for timely adjudication of transmissions. This burden is aggravated by excessive false positive alerts. We developed a novel artificial intelligence (AI)-based algorithm to reclassify ILR episodes aiming to decrease False Positive rate by 80% while maintaining 99% sensitivity. ObjectiveTo evaluate the performance of the algorithm in real-life conditions. To evaluate the performance of the algorithm in real-life conditions. MethodsMedtronic Reveal LINQ ILR patients were enrolled from 40 European medical centers. Using a cloud based remote monitoring platform, all episodes detected as “Abnormal” by ILRs were re-diagnosed by the AI algorithm. Healthcare professionals (HCPs) monitoring their patients on this platform could review the diagnosis suggested by the algorithm and then attribute a new diagnosis to any episode. The positive predictive value (PPV) and negative predictive value (NPV) of the algorithm detecting “Abnormal” episodes were evaluated with healthcare professionals’ diagnoses, excluding uncertain diagnoses (artifact, lead noise, atrial and ventricular monitoring). Medtronic Reveal LINQ ILR patients were enrolled from 40 European medical centers. Using a cloud based remote monitoring platform, all episodes detected as “Abnormal” by ILRs were re-diagnosed by the AI algorithm. Healthcare professionals (HCPs) monitoring their patients on this platform could review the diagnosis suggested by the algorithm and then attribute a new diagnosis to any episode. The positive predictive value (PPV) and negative predictive value (NPV) of the algorithm detecting “Abnormal” episodes were evaluated with healthcare professionals’ diagnoses, excluding uncertain diagnoses (artifact, lead noise, atrial and ventricular monitoring). ResultsAmong 10,296 “Abnormal” LINQ episodes analyzed by the AI algorithm and checked by HCPs, 4,442 (43.1%) were diagnosed as “Normal Rhythm” by the algorithm. HCPs submitted a certain diagnosis on 772 of these episodes, among which 750 were “Normal Rhythm”, resulting in a NPV of 97.1%. The other 5,854 (56.9%) “Abnormal” diagnoses were confirmed by the AI algorithm. HCPs submitted a certain diagnosis on 834 of these episodes, among which 773 were “Abnormal”, resulting in a PPV of 92.7%. Among 10,296 “Abnormal” LINQ episodes analyzed by the AI algorithm and checked by HCPs, 4,442 (43.1%) were diagnosed as “Normal Rhythm” by the algorithm. HCPs submitted a certain diagnosis on 772 of these episodes, among which 750 were “Normal Rhythm”, resulting in a NPV of 97.1%. The other 5,854 (56.9%) “Abnormal” diagnoses were confirmed by the AI algorithm. HCPs submitted a certain diagnosis on 834 of these episodes, among which 773 were “Abnormal”, resulting in a PPV of 92.7%. Conclusion

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

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

Het nut van implanteerbare looprecorders na een embolische beroerte van ongekende oorsprong

The use of implantable loop recorders after embolic stroke of undetermined source Unknown intermittent atrial fibrillation (AF) is a potential source of embolism in patients with embolic stroke of undetermined source (ESUS). Prolonged heart rhythm monitoring with implantable loop recorders (ILR) could increase the detection of AF. Patients with detected (subclinical) AF may benefit from a therapy with anticoagulants after ESUS. The authors of this article performed a retrospective analysis of patients who received an ILR after suspected ESUS at the University Hospitals of Leuven (Belgium) between April 2008 and March 2019. They describe the proportion of patients in whom AF was detected and studied the predictors of AF detection. With prolonged monitoring, the AF detection rate increased, mainly in the first 2 years after implantation. AF was detected in 28 out of 84 patients (33.3%) after a median follow-up of 8 months. Patients with AF were significantly older and tended to have more arterial hypertension. All patients with detected AF received oral anticoagulation. Although a 24-hour Holter monitoring and a week recorder were negative for AF detection, an ILR established (subclinical) AF in 1 out of 3 patients after ESUS.

Predictors for the detection of arrhythmia requiring pacemaker/ICD implantation-Results from a loop recorder study.

There are few large studies on which factors are associated with the occurrence of arrhythmias. Implantable loop recorders (ILR) are useful in detecting arrhythmia due to prolonged and continuous ECG monitoring. Therefore, the aim of this study is to identify and evaluate clinical characteristics and ECG parameters for predicting arrhythmias requiring pacemaker/ICD implantation by analyzing a study cohort with ILR. This bicentric study comprised a study cohort of 451 patients (mean age 64 ± 16 years, 209 women) receiving ILR implantation between 2011 and 2021. Patients were followed up on a 3 monthly outpatient interval. All arrhythmias with a pacemaker or ICD indication were considered clinically relevant. The primary study endpoint was the detection of clinically relevant arrhythmia. During a follow up of 678 ± 392 days, a clinically relevant arrhythmia was detected in 81 of 451 patients (18%). Multivariate analysis revealed five independent risk factors: coronary artery disease (HR 1.954, CI 1.077-3.546, p=.028), atrial fibrillation (HR 2.253, CI 1.201-4.228, p=.011), previous syncope (HR 6.404, CI 3.202-12.808, p<.001), right bundle branch block (HR 4.370, CI 2.215-8.621, p<.001) and left bundle branch block (HR 2.685, CI 1.116-6.461, p=.028). Our risk model, based on these independent predictors, divided the study cohort into patients with low (2%), intermediate (18%), medium (34%), and high (45%) risk for clinically relevant arrhythmia. By the use of ILR, a clinically relevant arrhythmia has been detected in almost one fifth of the study cohort. In addition, clinical and electrocardiographic parameters were shown to be suitable predictors of clinically relevant arrhythmia.

A Review of the Wide Range of Indications and Uses of Implantable Loop Recorders: A Review of the Literature

Implantable loop recorders (ILR) are devices that are implanted subcutaneously on the chest, which enables the continuous monitoring of arrhythmias for up to three years. These devices have an important role in helping to make a diagnosis and supporting decisions about the best patient management. There are currently three companies that produce ILRs. The Reveal DX and XT device is produced by Medtronic. The Confirm device is produced by Abbott. The Biomonitor III device is produced by Biotronik. The established indications for ILR include the management of transient loss of consciousness and the diagnosis of undocumented palpitations; however, they are also used for less established applications, including atrial fibrillation (AF) monitoring and risk stratification in patients with previous myocardial infarction or inherited cardiomyopathies. There is also diverse literature exploring the use of these devices in other populations, including patients with conditions such as congenital heart disease, amyloidosis, stroke, obstructive sleep apnea, renal transplant and patients who undergo procedures such as AF ablation and coronary artery bypass graft. In this review, we describe how the use of ILR has been applied in different settings, including patients with cardiac and non-cardiac conditions as well as post-cardiac procedures. We then discuss the potential issues related to using ILR in these other indications.

Paroxysmal atrial fibrillation as a predictor of pacemaker implantation in patients with unexplained syncope

BackgroundRecent studies using an implantable loop recorder (ILR) have reported on clinical predictors of pacemaker implantation in patients with unexplained syncope. However, atrial fibrillation (AF) was not included as a risk factor; this may be because the precise mechanism of AF (persistent or paroxysmal) has not been explicitly investigated. Thus, this study aimed to investigate the relationship between paroxysmal AF and cardiac syncope recurrence requiring pacemaker implantation in patients with an ILR owing to unexplained syncope. MethodsWe included consecutive patients who underwent ILR implantation for unexplained syncope between September 2010 and July 2020. ILR implantation was indicated for syncope that could not be explained even after comprehensive evaluation. ResultsOverall, 128 patients (72 men; mean age, 62.5 ± 21.1 years) underwent ILR evaluation. Paroxysmal AF was diagnosed before ILR implantation in 32 patients. Bradyarrhythmia with an indication for pacemaker implantation was detected in 33 patients. The number of syncopal episodes (≥ 3) in the previous 2 years, history of paroxysmal AF/asymptomatic sinus arrest, and bundle branch block were independent predictors of pacemaker implantation. Among patients with a history of paroxysmal AF, the PR interval was longer in those who required pacemaker implantation than in those who did not (194.8 vs 168.8 ms; p = 0.0356). ConclusionsParoxysmal AF is a significant predictor of recurrent syncope, leading to pacemaker implantation in patients with unexplained syncope. Careful history taking of paroxysmal AF is essential, and aggressive use of ILR is recommended to detect bradycardic events.

Role of subcutaneous implantable loop recorder for the diagnosis of arrhythmias in Brugada syndrome: A United Kingdom single-center experience.

Experience with implantable loop recorders (ILRs) in Brugada syndrome (BrS) is limited. The purpose of this study was to evaluate the indications and yield of ILR monitoring in a single-center BrS registry. Demographic, clinical and follow-up data of BrS patients with ILR were collected. Of 415 BrS patients recruited consecutively, 50 (12%) received an ILR (58% male). Mean age at ILR implantation was 44 ± 15 years. Thirty-one (62%) had experienced syncopal or presyncopal episodes, and 23 (46%) had palpitations. During median follow-up of 28 months (range 1-68), actionable events were detected in 11 subjects (22%); 7 had recurrences of syncope/presyncope, with 4 showing defects in sinus node function or atrioventricular conduction. New supraventricular tachyarrhythmias were recorded in 6 subjects; a run of fast nonsustained ventricular tachycardia was detected in 1 patient. Patients implanted with an ILR were less likely to show a spontaneous type 1 pattern or depolarization electrocardiographic (ECG) abnormalities compared to those receiving a primary prevention implantable-cardioverter defibrillator. Age at implantation, gender, Shanghai score, and ECG parameters did not differ betweensubjects with and those without actionable events. ILR-relatedcomplications occurred in 3 cases (6%). In a large cohort of BrS patients, continuous ILR monitoring yielded a diagnosis of tachy- or bradyarrhythmic episodes in 22% of cases. Recurrences of syncope were associated with bradyarrhythmic events. Use of ILR can be helpful in guiding the management of low-/intermediate-risk BrS patients and ascertaining the cause of unexplained syncope.

The utility of the implantable loop recorder in patients with a diagnosis or family history of long QT syndrome

Abstract Background There is limited published data on the use of implantable loop recorders (ILRs) in patients with long QT syndrome (LQTS). Purpose We sought to evaluate the utility of the ILR in patients who had a diagnosis of LQTS or who had a family history of LQTS. Methods We carried out a retrospective analysis of patients attending an Inherited Cardiac Conditions Clinic who had an active ILR and who had a diagnosis or family history of LQTS. Patient demographics, indications for ILR implantation and clinical outcomes were compiled. Results Nine patients with a diagnosis of LQTS and an active ILR were identified with an average age of 37 years. Genetic results were available for seven patients. Four patients had a confirmed pathogenic mutation (one KCNQ1 and three KCNH2), one patient had a variant of uncertain significance in SCN5A and two patients had negative genetic testing. Indications for implantation were syncope (n=4), recurrent altered consciousness episodes (n=1), assessment of occult arrhythmia or beta blocker complications (n=2), palpitations and dizziness (n=1) and nocturnal dyspnoea and palpitations (n=1). Mean follow-up was 706 days and average age at ILR implant was 35 years. The ILR for three patients was a second device, implanted after end of battery life of the initial ILR. ILR recordings led to a change in management in three patients: finding of paroxysmal atrial fibrillation (n=1), finding of nocturnal QTc of 511ms with a change in medications (n=1) and a pause leading to cessation of beta blocker (n=1). Eleven patients with a family history of LQTS and active ILR were identified. Nine patients were female, and the average age was 44.4 years. Genetic test results were available for five patients. Three patients had a pathogenic mutation in SCN5A, and two patients had negative genetic testing for common LQTS genes. Indications for implantation included syncope (n=5), lightheaded episodes (n=3) and risk assessment in gene carriers (n=3). The mean duration of ILR follow-up was 680 days and average age at ILR implant was 42.5 years. Five patients had no arrhythmia detected during ILR recording, two patients had supraventricular tachycardia identified, in two patients ILR data outruled a sinister cause for a symptomatic episode, one patient had documentation of SVT and brief NSVT which led to referral for electrophysiology study and one patient had no recurrence of symptoms and a second ILR was implanted. Conclusion ILRs were inserted in selected patients with a diagnosis of LQTS or in patients with a family history of LQTS or who were gene carriers. Rationale for ILR implantation included risk stratification, monitoring for occult arrhythmia and rhythm-symptom correlation in symptomatic patients. The ILR impacted management in almost 50% of patients and is considered an important tool in selected patients attending Inherited Cardiac Condition Clinics. Funding Acknowledgement Type of funding sources: None. Table 1

Unexplained falls in the elderly.

Falls are a geriatric syndrome affecting mortality, morbidity, and institutionalization. Falls are also the leading cause of unintentional injury and a common emergency department presentation. Physical and psychological issues may develop after falling, leading to increase in dependency and disability and their relative costs. The pathogenesis of falls is multi-factorial, being indeed the result of the interaction between increased individual susceptibility, high risk activities and environmental hazards. The patient should be evaluated for gait, standing balance, mobility, muscle weakness, cognitive status, osteoporosis risk, sensorial impairment, urinary incontinence, functional status, and for possible residential environmental hazards. It is also mandatory to obtain a full report of the circumstances and a careful therapeutic recognition. However not all falls are explainable. Indeed, retrograde amnesia and the frequent absence of a witness complicate history collection of falls in older adults. In this case, "the management of unexplained falls should be the same as that for unexplained syncope" as stated by the latest version of the European Society of Cardiology guidelines on syncope. In this context, the investigation of the cardiovascular autonomic nervous system and the use of implantable loop recorder have an increasing role. The present paper addresses the diagnostic approach to falls in older adults through a comprehensive multifactorial risk assessment and examines evidence and gaps on fall prevention strategies.

Usefulness of subcutaneous Implantable Loop Recorder in Brugada Syndrome. A single UK centre experience

Abstract Background Experience with implantable loop recorder (ILR) in Brugada Syndrome (BrS) is limited. Purpose We sought to evaluate the usefulness of continuous monitoring in BrS patients in a UK based Inherited Cardiac Conditions centre. Methods Subjects with BrS were consecutively recruited and demographic, clinical, device and follow-up data acquired. Results Of 452 subjects with BrS recruited in our centre, 41 (9%) received an ILR. Twenty-one (51%) were males. Twenty-four subjects (59%) had a high probability of BrS based on the Shanghai score. Mean age at implantation was 45.3±15.5 years. The indications for the implantation were: syncope or pre-syncope in 28 subjects (68%), palpitations in 12 (29%), family history of SADS in 1 case. Sixteen subjects presented with a spontaneous type 1 pattern, of whom 12 (75%) underwent an electrophysiological study for risk stratification which was negative. During a mean follow-up of 82±46 months (range 4.0–182), 5 new diagnoses of atrial fibrillation (AF) or supraventricular tachycardia were made; 3 subjects had symptomatic pathological pauses (in one case associated with fast AF) and underwent permanent pacemaker or ICD implantation; one subject experienced an asymptomatic episode of fast, non-sustained monomorphic ventricular tachycardia. In 2 cases the device was explanted prematurely due to site infection. Patients who received an ECG diagnosis following interrogation of the ILR were older (mean age 55±11 vs 43±16m p=0.04), although there were no differences in sex or Shanghai score. Conclusions In a large UK cohort of BrS patients, the use of ILR was low. However, continuous subcutaneous monitoring yielded a diagnosis of tachy- or brady-arrhythmic episodes in 22% of cases, and therefore can be helpful in guiding the management of low/intermediate risk BrS patients. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Robert Lancaster Memorial Fund