Comparison of autotriggered memory loop recorders versus standard loop recorders versus 24-hour Holter monitors for arrhythmia detection

SE-ResNet-ViT Hybrid Model for Noise Classification in Adhesive Patch-type Wearable Electrocardiographs

In purpose of screening arrhythmia, wearable adhesive patch-type electrocardiographs that can measure electrocardiogram continuously for 14 days have been replacing the 24-hour Holter monitor. The reason for that is the patch-type electrocardiograph being smaller and lighter than the Holter monitor, making it more convenient for patients to coexist with in their daily lives. However, this type of electrocardiograph generates a lot of noise signals due to movements during various physical activities and extended wear time.While analyzing electrocardiograms automatically using software, noise signals make the analysis difficult and they may be misclassified as arrhythmia signals. These misclassified signals require a lot of effort and time from clinical technicians to reclassify them as noise. To resolve this problem, this study hypothesized that a deep learning algorithm could be used to screen noise signals. We used 7,467 noise signals and 15,638 ECG signals collected from arrhythmia patients and healthy people. The signals were divided into 10 seconds segments and labeled by cardiologists. We split the data into training and test datasets, ensuring no patient overlap.A hybrid noise classification model, Squeeze and Excitation - Residual Network - Vision Transformer (SE-ResNet-ViT) was developed using the training and validation datasets with an 8:2 ratio. We evaluated the performance of the model using a test dataset. The best F1 score was 0.964. The proposed model can effectively screen for noise signals and potentially reducing the time and effort required by clinical technicians.

Use of a smartphone electrocardiogram to diagnose arrhythmias during exercise in athletes: a case series

Background

While athletes are generally very fit, intense exercise can increase the risk of atrial fibrillation. Moreover, other arrhythmias such as atrial flutter or supraventricular tachycardia can cause distressing, exercise-related symptoms. Given symptoms are infrequent and may occur during intense exertion, traditional monitoring devices are often impractical to use during exercise. Smartphone electrocardiograms (ECGs) such as the Alivecor Kardia device may be the portable and reliable tool required to help identify arrhythmias in this challenging population. This case series highlights the use of such devices in aiding the diagnosis of arrhythmias in the setting of exercise-related symptoms in athletes.

Case summary

The six cases in this series included one elite non-endurance athlete, two elite cricketers, one amateur middle-distance runner, and two semi-elite ultra-endurance runners, with an age range of 16-48 years. An accurate diagnosis of an arrhythmia was obtained in five cases (atrial fibrillation/flutter and supraventricular tachycardias) using the smartphone ECG, which helped guide definitive treatment. No arrhythmia was identified in the final case despite using the device during multiple symptomatic events.

Discussion

The smartphone ECG was able to accurately detect arrhythmias and provide a diagnosis in cases where traditional monitoring had not. The utility of detecting no arrhythmia during symptoms in one case was also highlighted, providing the athlete with the confidence to continue exercising. This reassurance and confidence across all cases is perhaps the most valuable aspect of this device, where clinicians and athletes can be more certain of reaching a diagnosis and undertaking appropriate management.

Remote and Wearable ECG Devices with Diagnostic Abilities in Adults: A State-of-the-Science Scoping Review

The electrocardiogram (ECG) records the electrical activity in the heart in real-time, providing an important opportunity to detecting various cardiac pathologies. The 12-lead ECG currently serves as the "standard" ECG acquisition technique for diagnostic purposes for many cardiac pathologies other than arrhythmias. However, the technical aspects of acquiring a 12-lead ECG are not easy and its usage is currently restricted to trained medical personnel, limiting the scope of its usefulness. Remote and wearable ECG devices have attempted to bridge this gap by enabling patients to take their own ECG using a simplified method at the expense of a reduced number of leads, usually a single-lead ECG. In this review article, we summarize the studies which investigate the use of remote ECG devices and their clinical utility in diagnosing cardiac pathologies. Eligible studies discussed FDA-cleared, commercially available devices that were validated on an adult population. We summarize technical logistics of signal quality and device reliability, dimensional and functional features, and diagnostic value. In summary, our synthesis shows that reduced-set ECG wearables have huge potential for long-term monitoring, particularly if paired with real-time notification techniques. Such capabilities make them primarily useful for abnormal rhythm detection and there is sufficient evidence that a remote ECG device can be more superior to traditional 12-lead ECG in diagnosing specific arrhythmias such as atrial fibrillation. However, this review identifies important challenges faced by this technology, highlighting the limited availability of clinical research examining their usefulness.

Enhanced detection of cardiac arrhythmias utilizing 14-day continuous ECG patch monitoring

BACKGROUND

To evaluate the performance of a single‑lead, 14-day continuous electrocardiogram (ECG) patch for the detection of arrhythmias compared to conventional 24-h monitoring.

METHODS

This prospective clinical trial enrolled patients suspected of arrhythmias but not diagnosed by 12‑lead ECGs. Each patient underwent a 24-h Holter and 14-day ECG patch simultaneously. Seven types of arrhythmias were classified: supraventricular tachycardia (SVT, repetitive atrial beats >4 beats), irregular SVT without P wave (>4 beats), AF/AFL (irregular SVT without P wave ≥30 s), pause ≥3 s, atrioventricular block (AVB; Mobitz type II, third-degree, two to one or high degree AVB), ventricular tachycardia (VT), and polymorphic VT.

RESULTS

A total of 158 patients were recruited (mean wear time:12.3 ± 3.2 days). The overall arrhythmia detection rate was higher with 14-day ECG patches (59.5%) compared to 24-h Holter (19.0%, P < 0.001). Up to 87.2% of arrhythmias recorded with 14-day ECG patches were not associated with symptoms. The 14-day ECG patch was associated with higher detection rates compared to the 24-h Holter in patients with SVT (52.5% versus 15.8%, P < 0.001), irregular SVT without P wave (12.7% versus 4.4%, P = 0.002), AF/AFL (9.5% versus 3.8%, P = 0.042), and critical arrhythmias (pause ≥3 s, AVB, VT, polymorphic VT) (16.5% versus 2.5%, P < 0.001). The 14-day ECG patch detected more than 2 types of arrhythmias in 5.1% of patients. No serious adverse events in patients wearing the 14-day ECG patch were reported.

CONCLUSIONS

The 14-day ECG patch outperformed 24-h Holter to detect overall, asymptomatic, critical and multiple arrhythmias. It is safe and has the potential to identify individuals with hidden arrhythmias, especially those with critical arrhythmias.

Cardiac Ambulatory Monitoring: New Wireless Device Validated Against Conventional Holter Monitoring in a Case Series

Background: Cardiac arrhythmias are very common but underdiagnosed due to their transient and asymptomatic nature. An optimization of arrhythmia detection would permit to better treat patients and could substantially reduce morbidity and mortality. The SmartCardia ScaAI wireless patch is a novel CE IIa approved, single-lead electrocardiographic (ECG) ambulatory monitor designed for cardiac arrhythmias detection.

Hypothesis: The accuracy of the new SmartCardia wireless patch to detect arrhythmias is comparable to the conventional Holter monitoring.

Methods: Patients referred for a suspicion of arrhythmia between February and March 2020 were included in the trial. Simultaneous ambulatory ECG were recorded using a conventional 24-h Holter and the SmartCardia. The primary endpoint was the detection of cardiac arrhythmias over the total wear time of the devices, defined as premature atrial contraction (PAC), supraventricular tachycardia ≥3 beats, premature ventricular contraction (PVC), and ventricular tachycardia ≥3 beats. Conduction abnormalities, pause ≥2 s and atrioventricular block (AVB), were also tracked. McNemar's test was used to compare the matched pairs of data from both devices.

Results: A total of 40 patients were included in the trial. Over the total wear time, there was no significant difference between the devices for ventricular and supraventricular arrhythmias detection. Pauses and AVB were equally identified by the two devices in three patients.

Conclusion: Over the total wear time, the SmartCardia device showed an accuracy to detect arrhythmia similar to the 24-h Holter monitoring: single-lead, adhesive-patch monitoring might become an interesting alternative to the conventional Holter monitoring.

Detection of Previously Unrecognized (Subclinical) Atrial Fibrillation

Atrial fibrillation (AF) has been associated with increased morbidity and mortality, even when symptoms are absent and the arrhythmia is unrecognized (e.g., subclinical AF [SCAF]). Despite substantial evidence demonstrating an association between AF and adverse outcomes, the role of mass screening for previously unrecognized SCAF, such that its individual and population risks may be reduced by prophylactic therapy, remains uncertain. Many AF screening strategies exist, from pulse palpation and single-use devices to implanted cardiac monitors; however, existing guidelines are insufficient in specifying who to screen and for how long. In general, higher age, more (and more severe) comorbidities, and longer monitoring periods are associated with greater detection of SCAF. Herein we review the significance of previously unrecognized SCAF and current status of SCAF detection methods. We then propose a clinical approach to help clinicians incorporate AF screening into their practice. In conclusion, we report that SCAF may not be rare, that inserted cardiac monitors have the highest yield of SCAF detection, that clinical concern regarding SCAF is appropriate, but that evidence for therapy mandates is still being collected.

When Is Syncope Arrhythmic?

Cardiac arrhythmia is a common cause of syncope. The prompt identification of arrhythmic syncope has diagnostic and prognostic implications. In this article, an approach to identifying and managing arrhythmic syncope is discussed, including key findings from the history, physical examination, electrocardiogram, role of risk stratification, use of supplemental investigations, and treatment.

Contemporary Yield of 24-hour Holter Monitoring: Role of Inter-Atrial Block Recognition

BACKGROUND

The diagnostic yield of 24-hour ECG Holter monitoring (24H) is currently overcome by alternative ECG monitoring techniquesand it needs to be optimized. The recognition of inter-atrial block (IAB) has emerged as a reliable indicator of patients at risk of atrial fibrillation relapses, and its role enhancing the yield of 24H is yet to be determined. We hypothesized that a presumably low yield of 24H may be ameliorated by means of incorporating the assessment for IAB.

METHODS

We retrospectively analyzed 1017 consecutive 24H registers performed in a Multidisciplinary Integrated Health Care Institution, in which a restrictive definition of diagnostic 24H findings was used. A univariate and multivariate regression analysis served to determine the variables associated with a higher 24H's yield, including the requesting medical specialty, type of indication and a number of clinical, echocardiographic and ECG variables, including IAB.

RESULTS

The mean age of our population was 62 ± 17 years (55% males). The majority of 24H were indicated from the Cardiology department (48%). The overall yield was 12.8%, higher for the assessment of the integrity of the electrical conduction system (26.1%) and poorer for the assessment of syncope (3.2%) and cryptogenic stroke (4.6%). The variables associated with higher diagnostic performance were indication from Cardiology (p < 0.001), IAB (p = 0.004), structural heart disease (p = 0.008) and chronic renal failure (p = 0.009). Patients ≤ 50 years old only retrieved a 7% yield. In the multivariate analysis, indication from Cardiology and IAB remained significant predictors of higher 24H's yield. In a secondary analysis including echocardiographic data, only identification of IAB remained statistically significant.

CONCLUSIONS

The recognition of IAB and the type of indication are major determinants of a higher 24H's diagnostic yield and may help to optimize the selection of candidates.

The quality of ECG data acquisition, and diagnostic performance of a novel adhesive patch for ambulatory cardiac rhythm monitoring in arrhythmia detection

BACKGROUND

Short and long ambulatory electrocardiographic monitoring with different systems is a widely used method to detect cardiac arrhythmias. In this study, we aimed to evaluate the effectiveness of a novel monitoring device on cardiac arrhythmia detection.

METHODS

We used two different protocols to evaluate device performance. For the first one, 36 healthy subjects were enrolled. The standard 12‑lead, 24-h Holter monitoring and the novel single lead electrocardiogram (ECG) Patch Monitor (EPM) device (BeyondCare®, Rooti Labs Ltd., Taipei, Taiwan) were simultaneously applied to all subjects for 24 h. The quality of ECG data acquisition of novel system was compared to that of standard Holter. The second phase included 73 patients that were referred from our outpatient arrhythmia clinic for evaluation of their symptoms relevant to the cardiac arrhythmias. Advanced algorithms, statistical methods (cross-correlation method, Pearson's correlation coefficient, Bland-Altman plots) were used to process and verify the acquired data.

RESULTS

The overall average beat per minute correlation between BeyondCare® and standard 12‑lead Holter was found 98% in 33 healthy subjects. The mean percentage of invalid measurements in BeyondCare® was 1.6% while the Holter's was 1.7%. In the second protocol of the study, prospective data from 67 patients who were referred for evaluation of their symptoms relevant to cardiac arrhythmias, showed that the mean BeyondCare® wear time was 4.7 ± 0.5 days out of five total days per protocol. The mean analyzable wear time was 93.6%. The water-resistant design enabled 73.5% of the participants to take a shower. 7.3% of participants had minor skin irritations related to the electrodes. Among the patients with detected arrhythmia (40.2% of all patients), 29.6% had their first arrhythmia after the initial two days period. A clinically significant pause was detected in one patient, ventricular tachycardia was detected in four patients, and supraventricular tachycardia was detected in 15 patients. Paroxysmal atrial fibrillation was identified in seven patients. Three of them had their first episodes after the second day of monitoring.

CONCLUSION

BeyondCare® Patch was well-tolerated and allowed prolonged time periods for continuous ECG monitoring, may result in an improvement in clinical accuracy and detection of arrhythmias by cloud-based artificial intelligence operating system.

Clinical impact of a novel ambulatory rhythm monitor in children

Traditional ambulatory rhythm monitoring in children can have limitations, including cumbersome leads and limited monitoring duration. The ZioTM patch ambulatory monitor is a small, adhesive, single-channel rhythm monitor that can be worn up to 2 weeks. In this study, we present a retrospective cross-sectional analysis of the ZioTM monitor's impact in clinical practice. Patients aged 0-18 years were included in the study. A total of 373 studies were reviewed in 332 patients. In all, 28.4% had structural heart disease, and 16.9% had a prior surgical, catheterisation, or electrophysiology procedure. The most common indication for monitoring was tachypalpitations (41%); 93.5% of these patients had their symptoms captured during the study window. The median duration of monitoring was 5 days. Overall, 5.1% of ZioTM monitoring identified arrhythmias requiring new intervention or increased medical management; 4.0% identified arrhythmias requiring increased clinical surveillance. The remainder had either normal-variant rhythm or minor rhythm findings requiring no change in management. For patients with tachypalpitations and no structural heart disease, 13.2% had pathological arrhythmias, but 72.9% had normal-variant rhythm during symptoms, allowing discharge from cardiology care. Notably, for patients with findings requiring intervention or increased surveillance, 56% had findings first identified beyond 24 hours, and only 62% were patient-triggered findings. Seven studies (1.9%) were associated with complications or patient intolerance. The ZioTM is a well-tolerated device that may improve what traditional Holter and event monitoring would detect in paediatric cardiology patients. This study shows a positive clinical impact on the management of patients within a paediatric cardiology practice.

When Silence Isn't Golden: The Case of "Silent" Atrial Fibrillation

Silent atrial fibrillation (AF) is common. In some patients, it is the only manifestation of AF, while in others, the AF may be symptomatic or both symptomatic and asymptomatic. Regardless, however, to date, the significance, detection, and management considerations for silent AF have been incompletely elucidated. This current study aimed to review, for both the current clinician and investigator, considerations and attitudes and the ongoing studies, respectively, with respect to silent AF. The methods used were a literature review and personal trial and clinical experience; the frequency of silent AF, concerns regarding silent AF, methods to detect silent AF, and prospective trials focused on the detection and management of silent AF were considered. The results of the literature search indicated that recently conducted relevant trials, such as PREDATE AF, ASSERT-II, and REVEAL AF, have shown that silent AF is frequent in patients with risk markers for AF and stroke in whom no prior AF history is present, and in whom no pacemaker or implantable cardioverter-defibrillator implantations have been previously performed. Furthermore, the GLORIA-AF Registry has reported the observance of more permanent AF and more prior strokes in asymptomatic patients. Ongoing trials such as ARTESiA and NOAH-AFNET 6 are expected to clarify the benefits and risks of oral anticoagulation in patients with silent AF. At present, when silent AF is detected in patients with stroke risk markers, most practitioners initiate an anticoagulation regimen.

Ambulatory electrocardiogram monitoring devices for evaluating transient loss of consciousness or other related symptoms

Capturing electrocardiograms (ECGs) during spontaneous events is the most powerful available tool to identify or exclude an arrhythmic cause of symptoms, and often can elucidate the definite diagnosis for different conditions, such as transient loss of consciousness (T-LOC), lightheadedness, or palpitations. Current ambulatory ECG monitoring technologies include 24-hour Holter, wearable event recorder, external loop recorder (ELR), and insertable cardiac monitoring (ICM). Of them, Holter ECG is most frequently used in daily practice in Japan, while ELR and ICM are less frequently used. However, the appropriate monitor choice should be based on the expected frequency of symptoms. Frequent events may be adequately detected by Holter ECG, but less frequent symptoms are more effectively assessed by longer-term monitoring (i.e., ELR or ICM). In this report, based on our clinical experience, we review the usefulness of ambulatory ECG monitoring devices, especially of ELR, for evaluating T-LOC and other potentially arrhythmia-related symptoms. Specifically, we focus on the use of ELR and ICM for evaluating Japanese patients with T-LOC.

2017 ISHNE-HRS expert consensus statement on ambulatory ECG and external cardiac monitoring/telemetry

Ambulatory ECG (AECG) is very commonly employed in a variety of clinical contexts to detect cardiac arrhythmias and/or arrhythmia patterns which are not readily obtained from the standard ECG. Accurate and timely characterization of arrhythmias is crucial to direct therapies that can have an important impact on diagnosis, prognosis or patient symptom status. The rhythm information derived from the large variety of AECG recording systems can often lead to appropriate and patient-specific medical and interventional management. The details in this document provide background and framework from which to apply AECG techniques in clinical practice, as well as clinical research.

The Use of Statins in the Treatment and Prevention of Atrial Fibrillation

The hydroxy-methyl-glutaryl-CoA reductase inhibitors (statins) are used extensively in the treatment of hyperlipidemia and in the primary and secondary prevention of cardiovascular and cerebrovascular diseases. Statins have also been demonstrated to confer secondary pleiotropic benefits in a variety of other disease processes, including a potential advantage in treating and preventing atrial fibrillation. These effects are primarily due to the up-regulation of endothelial nitric oxide synthase activity and a decrease in nicotinamide adenine dinucleotide phosphate oxidase production, which leads to downstream effects that improve the electromechanical function of atrial and myocardial tissue. The following serves as a focused and updated review of the published clinical data regarding the pleiotropic effects of statins in atrial fibrillation.

Incidence and timing of potentially high-risk arrhythmias detected through long term continuous ambulatory electrocardiographic monitoring

Background

Ambulatory electrocardiographic (ECG) monitoring is the standard to screen for high-risk arrhythmias. We evaluated the clinical utility of a novel, leadless electrode, single-patient-use ECG monitor that stores up to 14 days of a continuous recording to measure the burden and timing of potentially high-risk arrhythmias.

Methods

We examined data from 122,815 long term continuous ambulatory monitors (iRhythm ZIO® Service, San Francisco) prescribed from 2011 to 2013 and categorized potentially high-risk arrhythmias into two types: (1) ventricular arrhythmias including non-sustained and sustained ventricular tachycardia and (2) bradyarrhythmias including sinus pauses >3 s, atrial fibrillation pauses >5 s, and high-grade heart block (Mobitz Type II or third-degree heart block).

Results

Of 122,815 ZIO® recordings, median wear time was 9.9 (IQR 6.8–13.8) days and median analyzable time was 9.1 (IQR 6.4–13.1) days. There were 22,443 (18.3 %) with at least one episode of non-sustained ventricular tachycardia (NSVT), 238 (0.2 %) with sustained VT, 1766 (1.4 %) with a sinus pause >3 s (SP), 520 (0.4 %) with a pause during atrial fibrillation >5 s (AFP), and 1486 (1.2 %) with high-grade heart block (HGHB). Median time to first arrhythmia was 74 h (IQR 26–149 h) for NSVT, 22 h (IQR 5–73 h) for sustained VT, 22 h (IQR 7–64 h) for SP, 31 h (IQR 11–82 h) for AFP, and 40 h (SD 10–118 h) for HGHB.

Conclusions

A significant percentage of potentially high-risk arrhythmias are not identified within 48-h of ambulatory ECG monitoring. Longer-term continuous ambulatory ECG monitoring provides incremental detection of these potentially clinically relevant arrhythmic events.

Emerging role of digital technology and remote monitoring in the care of cardiac patients

Current available mobile health technologies make possible earlier diagnosis and long-term monitoring of patients with cardiovascular diseases. Remote monitoring of patients with implantable devices and chronic diseases has resulted in better outcomes reducing health care costs and hospital admissions. New care models, which shift point of care to the outpatient setting and the patient's home, necessitate innovations in technology.

Comparing 14-day adhesive patch with 24-h Holter monitoring

Barrett PM, Komatireddy R, Haaser S et al. Comparison of 24-hour Holter monitoring with 14-day novel adhesive patch electrocardiographic monitoring. Am. J. Med. 127(1), 95.e11–95.e17 (2014). The investigation of cardiac arrhythmias in the outpatient ambulatory setting has traditionally been initiated with the Holter monitor. Using the continuous recording over 24 or 48 h, the Holter monitor permits the detection of baseline rhythm, dysrhythmia and conduction abnormalities, including heart block and changes in the ST segment that may indicate myocardial ischemia. However, apart from the bulkiness and inconvenience of the device itself, the lack of extended monitoring results in a diagnostic yield of typically less than 20%. In this study by Barrett et al., 146 patients referred for the evaluation of cardiac arrhythmia were prospectively enrolled to wear both the 24-h Holter monitor and 14-day adhesive patch monitor (Zio Patch) simultaneously. The primary outcome was the detection of any one of six arrhythmias: supraventricular tachycardia, atrial fibrillation/flutter, pause >3 s, atrioventricular block, ventricular tachycardia, or polymorphic ventricular tachycardia/fibrillation. The adhesive patch monitor detected more arrhythmia events compared with the Holter monitor over the total wear time (96 vs. 61 events; p < 0.001), although the Holter monitor detected more events during the initial 24-h monitoring period (61 vs. 52 events; p = 0.013). Novel, single-lead, intermediate-duration, user-friendly adhesive patch monitoring devices, such as the Zio Patch, represent the changing face of ambulatory ECG monitoring. However, the loss of quality, automated rhythm analysis and inability to detect myocardial ischemia continue to remain important issues that will need to be addressed prior to the implementation of these new devices.

Incidence and risk factors for new-onset atrial fibrillation among patients with end-stage renal disease undergoing renal replacement therapy

Atrial fibrillation (AF) is prevalent in end-stage renal disease (ESRD) patients and negatively impacts patient outcomes. We explored the incidence and risk factors for new-onset AF among patients with ESRD undergoing renal replacement therapy, without a prior history of AF, retrieved from Taiwan's National Health Insurance Research Database (NHIRD). For each of 134,901 patients with ESRD, one age- and gender-matched control and one similarly matched patient with chronic kidney disease (CKD), a total of 404,703 patients, were selected from the NHIRD. The study endpoint was the occurrence of new-onset AF and patients were followed an average of 5.1 years. The incidence rates of AF were 12.1, 7.3, and 5.0 per 1000 person-years for ESRD, CKD, and control patients, respectively. Among patients with ESRD, age, hypertension, heart failure, coronary artery disease, peripheral arterial occlusive disease, and chronic obstructive pulmonary disease were significant risk factors for new-onset AF. Thus, patients with ESRD had a significantly higher risk of new-onset AF. The presence of multiple risk factors was associated with a higher possibility of AF occurrence.

Cryptogenic Stroke And Role Of Loop Recorder

Ischemic stroke is an important cause of morbidity and mortality when untreated. Identifying atrial fibrillation is important because atrial fibrillation ischemic related strokes are associated with an increased risk of disability and death compared with strokes of other etiologies and tend to recur without anticoagulation. However, atrial fibrillation detection can be difficult when it is asymptomatic and paroxistic and may be the underlying cause of some cryptogenic strokes or strokes of unknown origin. In this review, the different methods of cardiac monitoring to detect atrial fibrillation in patients with cryptogenic stroke are summarized, with a focus on loop recorder monitoring.

Role of extended external auto-triggered loop recorder monitoring for atrial fibrillation

BACKGROUND

Clinical outcomes after atrial fibrillation (AF) ablation are evaluated using standard 24-h Holter monitoring, and the large spontaneous variability of AF episodes and incidence of silent AF are major limitations. Further, symptoms generally decrease after AF ablation. METHODS AND RESULTS: Newly developed extended external auto-trigger loop recorders (ELR) were used for 14-day consecutive monitoring to detect atrial tachyarrhythmia (ATa). Continuous tracings were stored for the initial 24h. Among 500 examinations after AF ablation in 342 patients, 40 ATa episodes were manually detected in 25 patients during the initial 24h. All episodes including 27 asymptomatic episodes (67.5%) were successfully identified using ELR. Recurrent ATa after AF ablation were detected in 83 patients, and a median monitoring duration of 4.0 days (IQR, 1.0-7.75 days) was required to detect the first episode of recurrence. The sensitivity of 24-h monitoring in detecting arrhythmia recurrence was 27.7% relative to the 14-day monitoring. The diagnostic yield gradually improved with longer monitoring duration regardless of the period after the ablation procedure. Longer follow-up, however, was required to obtain similar diagnostic yield >1 year after as compared to <1 year after the procedure.

CONCLUSIONS

Twenty-four-hour monitoring detected a part of the ATa recurrences after ablation procedures. Extended ELR enabled arrhythmia monitoring for longer, with higher diagnostic yield of recurrence, regardless of patient symptoms.

Recurrence of atrial fibrillation within three months after pulmonary vein isolation for patients with paroxysmal atrial fibrillation: Analysis using external loop recorder with auto-trigger function

BACKGROUND

Pulmonary vein isolation (PVI) via catheter ablation has been shown to be a highly effective treatment option for patients with symptomatic paroxysmal atrial fibrillation (AF). The recurrence of AF within 3 months after PVI is not considered to be the result of ablation procedure failure, because early recurrence of AF is not always associated with late recurrence. We examined the usefulness of an external loop recorder with an auto-trigger function (ELR-AUTO) for the detection of atrial fibrillation following PVI to characterize early recurrence and to determine the implications of AF occurrence within 3 months after PVI.

METHODS

Fifty-three consecutive symptomatic patients with paroxysmal AF (age 61.6±12.6 years, 77% male) who underwent PVI and were fitted with ELR-AUTO for 7±2.0 days within 3 months after PVI were enrolled in this study.

RESULTS

Of the 33 (62.2%) patients who did not have AF recurrence within 3 months after PVI, only 1 patient experienced AF recurrence at 12 months. Seven (35%) of the 20 patients who experienced AF within 3 months of PVI experienced symptomatic AF recurrence at 12 months. The sensitivity, specificity, positive predictive value, and negative predictive value of early AF recurrence for late recurrence were 87.5%, 71.1%, 35.0%, and 96.9%, respectively.

CONCLUSIONS

AF recurrence measured by ELR-AUTO within 3 months after PVI can predict the late recurrence of AF. Freedom from AF in the first 3 months following ablation significantly predicts long-term AF freedom. ELR-AUTO is useful for the detection of symptomatic and asymptomatic AF.

Cardiac monitoring in patients with syncope: making that elusive diagnosis

Elucidating the cause of syncope is often a diagnostic challenge. At present, there is a myriad of ambulatory cardiac monitoring modalities available for recording cardiac rhythm during spontaneous symptoms. We provide a comprehensive review of these devices and discuss strategies on how to reach the elusive diagnosis based on current evidencebased recommendations.

Minimally invasive approach to the child with palpitations

Palpitations are a common reason for referral to a pediatric cardiologist. Although generally benign, palpitations are a significant cause for concern in the individual and their family. Similarly, palpitations may be the initial presentation of significant heart disease, resulting in heightened concern in the referring physician. Although emphasis is usually placed on excluding arrhythmia as the cause for palpitations, there are a variety of noncardiac causes for palpitations. The patient history and physical examination are the key components of the evaluation and guide subsequent investigations. In many cases, an immediate diagnosis cannot be made and additional testing may be required; this often includes further monitoring for episodes, cardiac imaging and ambulatory monitoring. Current technologies for ambulatory monitoring during symptoms include Holter monitoring and a variety of patient-activated event recorders, including implantable loop recorders. Each presents its own unique advantages and disadvantages to aid diagnosis in the management of a child with palpitations. The primary focus for the clinician is to determine whether the etiology is benign in nature or whether there is underlying heart disease that may carry a more serious prognosis.

Comparison of 24-hour Holter monitoring with 14-day novel adhesive patch electrocardiographic monitoring

BACKGROUND

Cardiac arrhythmias are remarkably common and routinely go undiagnosed because they are often transient and asymptomatic. Effective diagnosis and treatment can substantially reduce the morbidity and mortality associated with cardiac arrhythmias. The Zio Patch (iRhythm Technologies, Inc, San Francisco, Calif) is a novel, single-lead electrocardiographic (ECG), lightweight, Food and Drug Administration-cleared, continuously recording ambulatory adhesive patch monitor suitable for detecting cardiac arrhythmias in patients referred for ambulatory ECG monitoring.

METHODS

A total of 146 patients referred for evaluation of cardiac arrhythmia underwent simultaneous ambulatory ECG recording with a conventional 24-hour Holter monitor and a 14-day adhesive patch monitor. The primary outcome of the study was to compare the detection arrhythmia events over total wear time for both devices. Arrhythmia events were defined as detection of any 1 of 6 arrhythmias, including supraventricular tachycardia, atrial fibrillation/flutter, pause greater than 3 seconds, atrioventricular block, ventricular tachycardia, or polymorphic ventricular tachycardia/ventricular fibrillation. McNemar's tests were used to compare the matched pairs of data from the Holter and the adhesive patch monitor.

RESULTS

Over the total wear time of both devices, the adhesive patch monitor detected 96 arrhythmia events compared with 61 arrhythmia events by the Holter monitor (P < .001).

CONCLUSIONS

Over the total wear time of both devices, the adhesive patch monitor detected more events than the Holter monitor. Prolonged duration monitoring for detection of arrhythmia events using single-lead, less-obtrusive, adhesive-patch monitoring platforms could replace conventional Holter monitoring in patients referred for ambulatory ECG monitoring.

Benefits of monitoring patients with mobile cardiac telemetry (MCT) compared with the Event or Holter monitors

INTRODUCTION

This research is meant to establish if a patient monitored with mobile cardiac telemetry (MCT) sees different outcomes regarding diagnostic yield of arrhythmia, therapeutic management through the use of antiarrhythmic drugs, and cardiovascular costs incurred in the hospital setting when compared with more traditional monitoring devices, such as the Holter or the Event monitor.

MATERIALS AND METHODS

We conducted a retrospective analysis spanning 57 months of claims data from January 2007 to September 2011 pertaining to 200,000+ patients, of whom 14,000 used MCT only, 54,000 an Event monitor only, and 163,000 a Holter monitor only. Those claims came from the Truven database, an employer database that counts 2.8 million cardiovascular patients from an insured population of about 10 million members. We employed a pair-wise pre/post test-control methodology, and ensured that control patients were similar to test patients along the following dimensions: age, geographic location, type of cardiovascular diagnosis both in the inpatient and outpatient settings, and the cardiovascular drug class the patient uses.

RESULTS

First, the diagnostic yield of patients monitored with MCT is 61%, that is significantly higher than that of patients that use the Event monitor (23%) or the Holter monitor (24%). Second, patients naive to antiarrhythmic drugs initiate drug therapy after monitoring at the following rates: 61% for patients that use MCT compared with 39% for patients that use the Event and 43% for patients that use the Holter. Third, there are very significant inpatient cardiovascular savings (in the tens of thousands of dollars) for patients that undergo ablation, coronary artery bypass graft (CABG) and valve septa. Savings are more modest but nonetheless significant when it comes to the heart/pericardium procedure.

CONCLUSION

Given the superior outcome of MCT regarding both patient care and hospital savings, hospitals only stand to gain by enforcing protocols that favor the MCT system over the Event or the Holter monitor.

Diagnostic utility of a novel leadless arrhythmia monitoring device

Although extending the duration of ambulatory electrocardiographic monitoring beyond 24 to 48 hours can improve the detection of arrhythmias, lead-based (Holter) monitors might be limited by patient compliance and other factors. We, therefore, evaluated compliance, analyzable signal time, interval to arrhythmia detection, and diagnostic yield of the Zio Patch, a novel leadless, electrocardiographic monitoring device in 26,751 consecutive patients. The mean wear time was 7.6 ± 3.6 days, and the median analyzable time was 99% of the total wear time. Among the patients with detected arrhythmias (60.3% of all patients), 29.9% had their first arrhythmia and 51.1% had their first symptom-triggered arrhythmia occur after the initial 48-hour period. Compared with the first 48 hours of monitoring, the overall diagnostic yield was greater when data from the entire Zio Patch wear duration were included for any arrhythmia (62.2% vs 43.9%, p <0.0001) and for any symptomatic arrhythmia (9.7% vs 4.4%, p <0.0001). For paroxysmal atrial fibrillation (AF), the mean interval to the first detection of AF was inversely proportional to the total AF burden, with an increasing proportion occurring after 48 hours (11.2%, 10.5%, 20.8%, and 38.0% for an AF burden of 51% to 75%, 26% to 50%, 1% to 25%, and <1%, respectively). In conclusion, extended monitoring with the Zio Patch for ≤14 days is feasible, with high patient compliance, a high analyzable signal time, and an incremental diagnostic yield beyond 48 hours for all arrhythmia types. These findings could have significant implications for device selection, monitoring duration, and care pathways for arrhythmia evaluation and AF surveillance.

Screening for atrial fibrillation with baseline and intermittent ECG recording in an out-of-hospital population

BACKGROUND

the objective of this study is to investigate the detection rate of undiagnosed atrial fibrillation (AF) with short intermittent ECG recordings during four weeks among out-of-hospital patients, having at least one additional risk factor (CHADS2) for stroke.

METHOD

DESIGN

Cross-sectional study.

SETTING

Eight family practice centres and two hospital-based out-patient clinics in Sweden.

SUBJECTS

989 out-of-hospital patients, without known AF, having one or more risk factors associated with stroke (CHADS2).

INTERVENTIONS

All individuals were asked to perform 10-second handheld ECG recordings during 28 days, twice daily and when having palpitations.

MAIN OUTCOME MEASURES

Episodes of AF on handheld ECG recordings were defined as irregular supraventricular extrasystoles in series with a duration of 10 seconds.

RESULTS

928 patients completed registration. AF was found in 35 of 928 patients; 3.8% (95% confidence interval [CI] 2.7-5.2). These 35 patients had a mean age of 70.7 years (SD ± 7.7; range 53-85) and a median CHADS2 of 2 (range 1-4).

CONCLUSIONS

Intermittent handheld ECG recording over a four week period had a detection rate of 3.8% newly diagnosed AF, in a population of 928 out-of-hospital patients having at least one additional risk factor for stroke. Intermittent handheld ECG registration is a feasible method to detect AF in patients with an increased risk of stroke in whom oral anticoagulation (OAC) treatment is indicated.