Role of extended external loop recorders for the diagnosis of unexplained syncope, pre-syncope, and sustained palpitations

Caught in the Act: A Detailed Analysis of Cardiac Event Monitoring in a Cohort of Pediatric and ACHD Patients

BACKGROUND

Event monitors are being increasingly used in pediatric and adult congenital heart disease (ACHD) patients for arrhythmia evaluation. Data on their diagnostic yield are limited.

OBJECTIVES

To evaluate the diagnostic yield of event monitors, patient characteristics associated with critical events, and clinical response to events.

METHODS

We retrospectively assessed event monitors prescribed to patients at our institution's Heart Center from 2017 to 2020. Thirty-day event monitor tracings were reviewed by an electrophysiologist (EP) to identify critical events defined as supraventricular tachycardia (SVT, re-entrant, atrial tachycardia, atrial flutter, and atrial fibrillation), ventricular tachycardia (VT), atrioventricular block, and pauses greater than 3 s. Patient characteristics and treatment data were collected. Characteristics associated with events were assessed using multivariable logistic regression. Trends in monitor prescription over time, diagnostic yield, and clinical response to events were analyzed.

RESULTS

204/2330 (8.8%) event monitors had EP-confirmed critical events. Critical events included SVT (51.5%), VT (38.5%), atrioventricular block (4%), and pauses (6%). 129/198 (65%) patients with critical events underwent treatment. Event monitoring usage increased by 52% between 2017 and 2020 (p < 0.0001). Complex CHD (OR 2.1, 95% CI 1.3-3.4, p = 0.004), cardiomyopathy (OR 2.9, 95% CI 1.5-4.8, p < 0.001), and EP-ordered monitors (OR 1.6, 95% CI 1.2-2.1, p = 0.001) were more highly associated with critical events.

CONCLUSION

Event monitor use is common, and critical events were captured in 8.8% of patients. The majority of patients with critical events underwent treatment. Factors associated with critical events include EPs as ordering providers, complex CHD, and cardiomyopathy.

Diagnostic reliability of monitoring for premature atrial and ventricular complexes

AIMS

Short-term ambulatory electrocardiogram (ECG) monitoring is often used to assess premature atrial complex (PAC) and premature ventricular complex (PVC) frequency, but the diagnostic reliability is unknown. The objective of this study was to study the day-to-day variability of PAC and PVC frequency.

METHODS AND RESULTS

We used 14-day full-disclosure mobile cardiac telemetry recordings without atrial fibrillation in 8245 US patients aged 17-103 years to calculate the diagnostic reliability of shorter ambulatory ECG recordings compared with 14-day averages. Over 14 days, 1853 patients had ≥500 PACs/day, 410 patients had ≥5000 PACs/day, and 197 patients had ≥10 000 PACs/day; 1640 patients had ≥500 PVCs/day, 354 patients had ≥5000 PVCs/day, and 175 patients had ≥10 000 PVCs/day. After 3 days, the estimated daily PAC frequency differed by ≥50% from the 14-day mean in 25% of patients; for PVCs, the corresponding duration was 7 days. Ten days of monitoring were needed to estimate PAC and PVC frequency within ±20% of the overall 14-day frequency in 80% of patients. For daily PAC and PVC frequencies ≥10 000, single-day estimation had a specificity of 99.3% [95% confidence interval (CI) 99.1-99.5] at a sensitivity of 76.6 (95% CI 70.1-80.4%) for PACs and a 99.6% (95% CI 99.4-99.7%) specificity at 79.4 (95% CI 72.7-85.2) sensitivity for PVCs. After 7 days, the sensitivity increased to 88.8% (95% CI 83.6-92.9) for PACs and 86.9% (95% CI 80.9-91.5%) for PVCs.

CONCLUSION

While there is substantial daily variability across most PAC and PVC levels, findings of ≥10 000 PACs or PVCs are highly specific and do not need to be confirmed with longer recordings.

Serious outcomes among emergency department patients with presyncope: A systematic review

BACKGROUND

Syncope is transient loss of consciousness, and in presyncope, patients experience same prodromal symptoms without losing consciousness. While studies have extensively reported the risk of serious outcome among emergency department (ED) syncope, the outcome for patients with presyncope and their management are not well studied. We undertook a systematic review to assess the occurrence/identification of short-term (30-day) serious outcomes among ED patients with presyncope.

METHODS

ED studies that enrolled patients with presyncope and reported any short-term serious outcome were included. Studies that enrolled patients without presyncope (e.g., hypoglycemia, seizure, and stroke) were excluded. We restricted our study to only English publications and searched the MEDLINE, Embase, Scopus, and Web of Science from the inception date to July 2023. We used SIGN 50 tool for assessment of risk of bias.

RESULTS

In total, 1788 articles were screened by two reviewers and 32 articles were selected for full-text assessment. Five (four prospective and one retrospective) studies with 2741 presyncope patients were included. Four studies were from North America and the fifth one was from Europe. Included studies had weaknesses due to risk of bias, but all had acceptable quality. The prevalence of overall adverse outcome varied 4.4%-26.8% for all adults and 5.5%-18.7% among older patients; arrhythmia was the most prevalent (17.4% in one study), followed by anemia/hemorrhage as reported in different studies. Among older patients, myocardial infarction was the third most common serious outcome reported in one study.

CONCLUSIONS

The prevalence of short-term serious outcomes varies from 4% to 27% among ED patients with presyncope in our review, with arrhythmia being the most common serious outcome. Our review indicates that presyncope may carry a similar risk to syncope, and hence, the same level of caution should be exercised for ED presyncope management as syncope.

An overview of the electrocardiographic monitoring devices in sports cardiology: Between present and future

BACKGROUND

Athletes represent a mainly healthy population, which however could be considered at risk of major arrhythmic events, especially in case of undiagnosed cardiomyopathies. For this reason, the periodical sports medicine examination and the electrocardiography are essential tools in the cardiovascular screening, even though they do not always succeed in identifying rhythm disturbances, particularly when asymptomatic or rarely symptomatic.

HYPOTHESIS

Prolonged cardiac monitoring often enables clinicians to stratify the arrhythmic risk and reach the diagnosis. The technological progress of the last decades has produced an always-increasing number of heart rhythm monitoring devices, starting from the 24-hour electrocardiogram Holter monitoring and ending with the wide world of wearable devices.

METHODS

In the literature, the extreme utility of this equipment in the patients affected by cardiovascular diseases and in the general population is well established. On the contrary, athletes-based randomized trials or large-scale epidemiological studies targeting the frequency of cardiac symptoms and the use of cardiac monitoring are missing, while an ever-growing number of case series and small observational studies are flourishing in recent years.

RESULTS

The present review showcases the available electrocardiographic monitoring options, principally in the medical setting, listing their characteristics, their indications, their supporting evidence, and their general pros and cons.

CONCLUSIONS

The ultimate goal of this review is guiding physicians through the wide variety of heart rhythm monitoring options in the specific subfield of sports cardiology, when an arrhythmia is suspected in an athlete, to tailor the diagnostic process and favor the best diagnostic accuracy.

Diagnostic yield of ambulatory cardiac monitoring in pediatric patients with palpitations

Background

Palpitations are a frequent reason for referral to pediatric cardiology providers and diagnostic workup includes ambulatory cardiac monitoring. While common practice, the diagnostic yield is unknown in the pediatric population. The objective is to evaluate the diagnostic yield of 24-h Holter and extended ambulatory cardiac monitoring in pediatric patients with palpitations.

Methods and Results

All pediatric patients aged 10-18 years who had ambulatory cardiac monitoring (1-30 days) through the Pocket Electrocardiogram (PocketECG™) system (Medi-Lynx) between January 2016 and July 2020 were included. Patients with an International Classification of Diseases-10 diagnosis code of palpitations (R00.2) during enrollment were evaluated separately. Tachyarrhythmia diagnoses included atrial fibrillation (AF), nonsustained supraventricular tachycardia (nSVT), supraventricular tachycardia (SVT), nonsustained ventricular tachycardia (nVT), and ventricular tachycardia (VT). Age, heart rates, arrhythmia type, and symptomatic transmission data were collected and analyzed. A total of 2388 patients (mean age 11.6 years, 58% F) with the R00.2 code had ambulatory cardiac monitoring (28% 24-h Holter, 72% extended) performed during the study period and there were 6287 total patients (mean age 13.9 years, 54% F) that underwent ambulatory cardiac monitoring (42% 24-h Holter, 58% extended) during that time. Of 2388 patients, 321 (13%) were diagnosed with tachyarrhythmia: AF (9), nSVT (192), SVT (59), and nVT (61). In the overall cohort, 764 (12%) patients were diagnosed with tachyarrhythmia: AF (22), nSVT (478), SVT (85), nVT (177), and VT (2). Symptomatic transmissions with normal cardiac rhythm were common in the R00.2 (n = 1697, 71%) and overall (n = 3848, 61%) groups. No episodes of nSVT, SVT, nVT, or VT were associated with symptomatic transmissions.

Conclusion

Ambulatory cardiac monitors are an integral part of the diagnostic workup for pediatric palpitations patients and have demonstrated a high yield of combined positive arrhythmia diagnoses and symptomatic normal transmissions. Further prospective study of this population with the integration of clinical information is warranted.

Current Advancement in Diagnosing Atrial Fibrillation by Utilizing Wearable Devices and Artificial Intelligence: A Review Study

Atrial fibrillation (AF) is a common arrhythmia affecting 8–10% of the population older than 80 years old. The importance of early diagnosis of atrial fibrillation has been broadly recognized since arrhythmias significantly increase the risk of stroke, heart failure and tachycardia-induced cardiomyopathy with reduced cardiac function. However, the prevalence of atrial fibrillation is often underestimated due to the high frequency of clinically silent atrial fibrillation as well as paroxysmal atrial fibrillation, both of which are hard to catch by routine physical examination or 12-lead electrocardiogram (ECG). The development of wearable devices has provided a reliable way for healthcare providers to uncover undiagnosed atrial fibrillation in the population, especially those most at risk. Furthermore, with the advancement of artificial intelligence and machine learning, the technology is now able to utilize the database in assisting detection of arrhythmias from the data collected by the devices. In this review study, we compare the different wearable devices available on the market and review the current advancement in artificial intelligence in diagnosing atrial fibrillation. We believe that with the aid of the progressive development of technologies, the diagnosis of atrial fibrillation shall be made more effectively and accurately in the near future.

The Role of External Loop Recorders in Arrhythmia-Related Symptoms in Children: A Single Center Experience

In this study, we report our experience with the use of external loop recorders (ELRs), in terms of diagnostic efficiency according to symptoms and symptom-rhythm correlation in pediatric patients. We evaluated ELRs applied to 178 patients between April 2017 and November 2020 at our center. The mean age of 172 patients included in the study was 13.6 ± 3.8 years, and 69.8% were female. ELR indications were palpitations in 98 (56.9%) cases, chest pain and palpitations in 43 (25%) cases, presyncope/syncope in 28 (16.2%) cases, and pacemaker/ implantable cardioverter-defibrillator (ICD) problems in 3 (0.2%) cases. ELR recording times were 14.2 ± 9.7 days on average, ranging from 2 to 67 days. While the symptom-rhythm correlation was 29.1% in total, when the indications were evaluated one by one, this correlation was found to be 30.2% in palpitations, 34.7% in chest pain and palpitations, and 10.7% in presyncope/syncope. The total diagnostic efficiency was 68.1%. In the follow-up of ELR cases, a total of 139 (80.8%) patients received clinical follow-up without medication, 15 (8.8%) patients received medical treatment, and 18 (10.4%) patients underwent EPS. The cardiac ELR system is useful in detecting underlying arrhythmias. Demonstrating sinus tachycardia at the time of the symptom may be seen as negative finding, but while experiencing symptoms, it is diagnostically valuable and may help avoid further investigation with costly and invasive diagnostic procedures. For diagnostic efficiency and cost effectiveness, the optimal recording time is 2 weeks, but it should be extended to 4 weeks in cases such as of presyncope/syncope that cannot be explained with a 2-week ELR use.

Diagnostic Efficacy of a Single-Lead Ambulatory 14-Day ECG Monitor in Symptomatic Children

Background

The CardioSTAT is a single-lead ambulatory electrocardiography monitor that has been validated for use in adult patients. Recording is made through 2 electrodes positioned in a lead-I configuration, and the device allows monitoring for 2, 7, or 14 days. We sought to investigate the efficacy of this device in children with paroxysmal palpitations.

Methods

In phase I, the quality of tracings from simultaneous CardioSTAT recordings and D1-lead recordings of a standard 12-lead electrocardiography machine in 23 children were compared. Phase II was a prospective observational cohort study comparing arrhythmia detection using the CardioSTAT vs currently used devices (24-hour Holter monitor and the Cardiomemo loop recorder) in 52 children complaining of palpitations.

Results

In Phase I, all but 3 rhythm strips were correctly identified. The pacing spikes on 3 strips were not adequately identified by the observers for the CardioSTAT recording. In Phase II, symptomatic episodes were reported in 42%, 73%, and 100% of subjects during monitoring with the Holter, Cardiomemo, and CardioSTATdevices, respectively. An abnormal rhythm was detected in 13%, 23%, and 35% of subjects by the Holter, Cardiomemo, and CardioSTAT monitors, respectively. The underlying rhythm during symptomatic events was determined in 90% of cases with the CardioSTAT monitor, whereas it was determined in only 19% and 29% of cases using the Holter and Cardiomemo monitors, respectively.

Conclusions

The CardioSTAT monitor provided good-quality tracings and was superior to the 24-hour Holter monitor and the Cardiomemo loop recorder in determining the presence or absence of pathologic arrhythmia in the study cohort.

Managing athletes with palpitations of unknown origin with an external loop recorder: a cohort study

BACKGROUND

Palpitations in athletes are usually benign, but the presence of major cardiac arrhythmias should be ruled out despite the infrequent appraisal of symptoms. External loop recorders (ELR) are promising to identify arrhythmias in these circumstances, but experiences in athletes are lacking. We aimed to investigate the feasibility and diagnostic yield of an ELR in athletes with unexplained palpitations in a cohort study.

METHODS

122 consecutive subjects (61 athletes and 61 sedentary controls) with sporadic palpitations and inconclusive diagnosis were enrolled and equipped with an ELR. Findings were categorized as major and minor arrhythmic findings, non-arrhythmic findings or negative monitoring.

RESULTS

Long-term ELR monitoring was feasible in all subjects, with median duration of 12 (11; 15) days. Major arrhythmic events during palpitations were found in 9 (14.8%) athletes: 7 experienced sustained paroxysmal supraventricular tachycardia, and 2 had non sustained ventricular tachycardia. Minor arrhythmic events (premature supraventricular or ventricular beats) were observed in 13 athletes (21.3%). Non-arrhythmic findings (i.e., sinus rhythm or sinus tachycardia) were recorded in 28 athletes (45.9%), whereas 11 (18%) had negative monitoring. In the sedentary group, arrhythmic events were similar for types and frequency to athletes. The diagnostic yield of loop monitoring was 82.8% in the overall population and 82.0% in the athlete's group.

CONCLUSIONS

In the management of an athlete symptomatic with unexplained palpitations after 24-hour ECG monitoring and stress test, ELR is an efficient tool to identify major arrhythmic events, which can be present in up to 10% of symptomatic athletes during practice and competition.

Palpitation: Extended Electrocardiogram Monitoring: Which Tests to Use and When

Palpitation is common. It is often accompanied by dizziness, lightheadedness, near syncope, and even syncope. It may be difficult to confirm a diagnosis in patients with infrequent symptoms. Several tools are available to document arrhythmias in the workup of a patient with palpitation, including 24-hour Holter monitoring, 30-day external continuous monitoring, and implantable loop recorders. A number of private companies are now able to empower patients to monitor heart rates and even give accurate rhythm strips. This article reviews the current data on how to make the diagnosis and which tools to use in the primary care setting.

Ambulatory Arrhythmia Detection with ZIO® XT Patch in Pediatric Patients: A Comparison of Devices

Ambulatory electrocardiogram monitoring devices can be used for 24-72 h to detect arrhythmias. A new device, the ZIO® XT Patch has cardiac monitoring capabilities that can be utilized for up to 14 days. The purpose of this study is to describe duration of ZIO use by age, and to compare its time to arrhythmia detection with the Holter monitor in a pediatric population. A single-center, retrospective review of patients < 18 years of age who underwent clinical investigation with ZIO from October 2014 to February 2016 was performed. An age-matched cohort was utilized to compare ZIO to Holter monitor results. Demographic and diagnostic data, time to first arrhythmia, and arrhythmia burden were analyzed. A total of 406 ZIO were prescribed; median age 12.7 years and 50% male subjects. Median duration of ZIO monitoring significantly increased with age (p < 0.001). 499 Holter monitors were prescribed on a statistically different age group. Arrhythmia detection rates were similar between groups, 10% (n = 42) by ZIO and 9% (n = 45) by Holter (p = NS). The majority of arrhythmias (57%) detected by ZIO were after 24 h (p < 0.0001). All arrhythmias detected by Holter monitor occurred within 24 h (p < 0.0001), mean duration of wear was 24.1 h, range 0.5-48 h. The ZIO® XT Patch may be considered as an ambulatory ECG monitor to diagnose arrhythmia in pediatric patients of all ages. Increasing patient age resulted in increasing duration of ZIO monitoring. Majority of arrhythmias detected with ZIO were identified after 24 h, which would have been missed by other short-term monitors.

Indications for permanent pacing in dogs and cats

Pacemaker implantation is considered as a standard procedure for treatment of symptomatic bradycardia in both dogs and cats. Advanced second-degree and third-degree atrioventricular blocks, sick sinus syndrome, persistent atrial standstill, and vasovagal syncope are the most common rhythm disturbances that require pacing to either alleviate clinical signs or prolong survival. Most pacemakers are implanted transvenously, using endocardial leads, but rarely epicardial leads may be necessary. To decide whether a patient is a candidate for pacing, as well as which pacing modality should be used, the clinician must have a clear understanding of the etiology, the pathophysiology, and the natural history of the most common bradyarrhythmias, as well as what result can be achieved by pacing patients with different rhythm disturbances. The goal of this review was, therefore, to describe the indications for pacing by evaluating the available evidence in both human and veterinary medicine. We described the etiology of bradyarrhythmias, clinical signs and electrocardiographic abnormalities, and the choice of pacing modality, taking into account how different choices may have different physiological consequences to selected patients. It is expected that this review will assist veterinarians in recognizing arrhythmias that may require permanent pacing and the risk-benefit of each pacing modality and its impact on outcome.

A Systematic Review of Noninvasive Electrocardiogram Monitoring Devices for the Evaluation of Suspected Cardiovascular Syncope

The aims of this study were (1) to identify research publications studying noninvasive electrocardiogram (ECG) monitoring devices, (2) to define and categorize current technology in noninvasive ECG recording, and (3) to discuss desirable noninvasive recording features for personalized syncope evaluation to guide technological advancement and future studies. We performed a systematic review of the literature that assessed noninvasive ECG-monitoring devices, regardless of the reason for monitoring. We performed an Internet search and corresponded with syncope experts and companies to help identify further eligible products. We extracted information about included studies and device features. We found 173 relevant papers. The main reasons for ECG monitoring were atrial fibrillation (n = 45), coronary artery disease (n = 10), syncope (n = 8), palpitations (n = 8), other cardiac diseases (n = 67), and technological aspects of monitoring (n = 35). We identified 198 devices: 5 hospital telemetry devices, 12 patches, 46 event recorders, 70 Holter monitors, 23 external loop recorders, 20 mobile cardiac outpatient telemetries, and 22 multifunctional devices. The features of each device were very heterogeneous. There are a large number of ECG-monitoring devices with different features available in the market. Our findings may help clinicians select the appropriate device for their patients. Since there are only a few published articles analyzing their usefulness in syncope patients, further research might improve their use in this clinical setting.

Optimal duration and predictors of diagnostic utility of patient-activated ambulatory ECG monitoring

Objective

We studied the optimal duration of ambulatory event monitors for symptomatic patients and the predictors of detected events.

Methods

Patients with palpitations or dizziness received a patient-activated handheld event monitor which records 30 s single-lead ECG strips. Patients were monitored in an ambulatory setting for a range of 1-4 weeks and ECG strips interpreted by five independent electrophysiologists. Event pick-up rates and clinical covariates were analysed.

Results

Of 335 consecutive adults (age 50±16 years, 58% female) with palpitations (94%) and dizziness (25%) monitored, 286 patients (85%) reported events, and clinically significant events were detected in 86 (26%) patients. Of these 86 patients, 26% had ≥2 significant events, and 73% had events detected in the first 3 days. No significant events were detected after 12 days. The most common ECG abnormalities detected were premature ventricular ectopy (38%), premature atrial ectopy (37%) and atrial fibrillation (AF)/atrial flutter (34%). A history of AF (adjusted OR (AOR) 4.2, 95% CI 1.1 to 15.8), previous arrhythmia (AOR 2.8, 95% CI 2.3 to 5.9) and previous abnormal ambulatory monitoring (AOR 3.4, 95% CI 1.0 to 9.4) were associated with detection of clinically significant events. Patients older than 50 years were 82% more likely to have a clinically significant event (OR 1.8, 95% CI 1.3 to 3.6).

Conclusion

Patient-activated ambulatory event monitoring for 7 days may be sufficient in the diagnosis of symptomatic patients as significant events first detected beyond 10 days were rare. Patients with a history of AF, arrhythmia or previous abnormal ambulatory monitoring may require even shorter monitoring periods.

Portable out-of-hospital electrocardiography: A review of current technologies

Background

Availability of portable and home‐based electrocardiography (ECG) is an important medical innovation, which has a potential to transform medical care. We performed this review to understand the current state of out‐of‐hospital portable ECG technologies with respect to their scope, ease of use, data transmission capabilities, and diagnostic accuracy.

Methods

We conducted PubMed and Internet searches for “handheld” or “wearable” or “patch” electrocardiography devices to enlist available technologies. We also searched PubMed with names of individual devices to obtain additional citations. We classified available devices as a “single limb lead ECG recording devices” and chest‐lead “ECG recording devices.” If a device used more than three electrodes, it was defined as a conventional electrocardiography or Holter machine and was excluded from this review.

Results

We identified a total of 15 devices. Overall, only six of these devices (five single lead and one chest lead) featured in published medical literature as identified from PubMed search. A total of 13 citations were available for the single limb lead ECG recording devices and 6 citations for the chest‐lead ECG recording devices.

Conclusions

Despite the increase in number of such devices, published biomedical literature regarding their diagnostic accuracy, reproducibility, or utility is scant.

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.

Catheter Ablation: General Principles and Advances

Besides antiarrhythmic medication, there are now very good options for a potentially curative therapy by catheter ablation targeting the origin of the underlying arrhythmias in patients with complex congenital heart disease. Three-dimensional (3D) reconstruction of tomographic imaging (MRI or computed tomography) is helpful to understand the underlying cardiac anatomy, identify the most likely target chamber, and help with planning access. Use of the available 3D mapping systems (sequential or simultaneous acquisition) and (if available) more advanced navigation systems, such as remote magnetic navigation, can improve the acute and long-term outcomes of catheter ablation in congenital heart disease.

Neurological Complications of Cardiac Disease

This article focuses on the complex interactions between the cardiovascular and neurologic systems. Initially, we focus on neurological complications in children with congenital heart disease both secondary to the underlying cardiac disease and complications of interventions. We later discuss diagnosis and management of common syncope syndromes with emphasis on vasovagal syncope. We also review the diagnosis, classification, and management of children and adolescents with postural orthostatic tachycardia syndrome. Lastly, we discuss long QT syndrome and sudden unexpected death in epilepsy (SUDEP), reviewing advances in genetics and current knowledge of pathophysiology of these conditions. This article attempts to provide an overview of these disorders with focus on pathophysiology, advances in molecular genetics, and current medical interventions.

The role of the atrial electromechanical delay in predicting atrial fibrillation in beta-thalassemia major patients

BACKGROUND

Paroxysmal atrial tachyarrhythmias frequently occur in beta-thalassemia major (β-TM) patients. The aim of the current study was to evaluate the atrial electromechanical delay (AEMD) in a large β-TM population with normal cardiac function and its relationship to atrial fibrillation (AF) onset.

METHODS

Eighty β-TM patients (44 men, 36 women), with a mean age of 36.2 ± 11.1 years, and 80 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of AF during a 5-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 6 months. Intra-AEMD and inter-AEMD of both atria were measured through tissue Doppler echocardiography. P-wave dispersion (PD) was carefully measured using 12-lead electrocardiogram (ECG).

RESULTS

Compared to the healthy control group, the β-TM patients showed a statistically significant increase in inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD. Dividing the β-TM group into two subgroups (patients with or without AF), the inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD were significantly higher in the subgroup with AF compared to the subgroup without AF. There were significant good correlations of intra-left AEMD and inter-AEMD with PD. A cut-off value of 40.1 ms for intra-left AEMD had a sensitivity of 76.2% and a specificity of 97.5% in identifying β-TM patients with AF risk. A cut-off value of 44.8 ms for inter-AEMD had a sensitivity of 81.2% and a specificity of 98.7% in identifying this category of patients.

CONCLUSIONS

Our results showed that the echocardiographic atrial electromechanical delay indices (intra-left and inter-AEMD) and the PD were significantly increased in β-TM subjects with normal cardiac function. PD and AEMD represent non-invasive, inexpensive, useful, and simple parameters to assess the AF risk in β-TM patients.

Holter Monitoring and Loop Recorders: From Research to Clinical Practice

Holter monitors are tools of proven efficacy in diagnosing and monitoring cardiac arrhythmias. Despite the fact their use is widely prescribed by general practitioners, little is known about their evolving role in the management of patients with cryptogenic stroke, paroxysmal atrial fibrillation, unexplained recurrent syncope and risk stratification in implantable cardioverter defibrillator or pacemaker candidates. New Holter monitoring technologies and loop recorders allow prolonged monitoring of heart rhythm for periods from a few days to several months, making it possible to detect infrequent arrhythmias in patients of all ages. This review discusses the advances in this area of arrhythmology and how Holter monitors have improved the clinical management of patients with suspected cardiac rhythm diseases.

Evidence-based Recommendations for the Evaluation of Palpitations in the Primary Care Setting

Palpitations are a symptom of many cardiac and noncardiac conditions. The patient's history, physical examination, appropriately directed laboratory tests, and basic electrocardiogram are helpful in evaluating palpitations and may be essential to finding a diagnosis. There are many outpatient options for the evaluation of palpitations caused by a presumed cardiogenic cause. These evaluation tools include Holter monitor, event monitor, transtelephonic electrocardiographic monitor, treadmill exercise stress test, echocardiography, and electrophysiologic studies. Most patients can be evaluated as an outpatient, but there are reasons, such as hemodynamic compromise, that may require admission to an inpatient setting to complete the diagnostic workup.

External prolonged electrocardiogram monitoring in unexplained syncope and palpitations: results of the SYNARR-Flash study

AIMS

SYNARR-Flash study (Monitoring of SYNcopes and/or sustained palpitations of suspected ARRhythmic origin) is an international, multicentre, observational, prospective trial designed to evaluate the role of external 4-week electrocardiogram (ECG) monitoring in clinical work-up of unexplained syncope and/or sustained palpitations of suspected arrhythmic origin.

METHODS AND RESULTS

Consecutive patients were enrolled within 1 month after unexplained syncope or palpitations (index event) after being discharged from emergency room or hospitalization without a conclusive diagnosis. A 4-week ECG monitoring was obtained by external high-capacity loop recorder (SpiderFlash-T(®), Sorin) storing patient-activated and auto-triggered tracings. Diagnostic monitorings included (i) conclusive events with reoccurrence of syncope or palpitation with concomitant ECG recording (with/without arrhythmias) and (ii) events with asymptomatic predefined significant arrhythmias (sustained supraventricular or ventricular tachycardia, advanced atrio-ventricular block, sinus bradycardia <30 b.p.m., pauses >6 s). SYNARR-Flash study enrolled 395 patients (57.7% females, 56.9 ± 18.7 years, 28.1% with syncope, and 71.9% with palpitations) from 10 European centres. For syncope, the 4-week diagnostic yield was 24.5%, and predictors of diagnostic events were early start of recording (0-15 vs. >15 days after index event) (OR 6.2, 95% CI 1.3-29.6, P = 0.021) and previous history of supraventricular arrhythmias (OR 3.6, 95% CI 1.4-9.7, P = 0.018). For palpitations, the 4-week diagnostic yield was 71.6% and predictors of diagnostic events were history of recurrent palpitations (P < 0.001) and early start of recording (P = 0.001).

CONCLUSION

The 4-week external ECG monitoring can be considered as first-line tool in the diagnostic work-up of syncope and palpitation. Early recorder use, history of supraventricular arrhythmia, and frequent previous events increased the likelihood of diagnostic events during the 4-week external ECG monitoring.

Impact of Continuous Positive Airway Pressure Therapy on Atrial Electromechanical Delay in Obesity-Hypoventilation Syndrome Patients

BACKGROUND

Obesity-hypoventilation syndrome (OHS) is defined as daytime hypercapnia and hypoxemia in obese patients with sleep-disordered breathing. We evaluated the electrocardiographic P-wave duration and dispersion (PD) and echocardiographic noninvasive indicators of atrial conduction heterogeneity in OHS patients and the impact of CPAP on atrial conduction and atrial fibrillation incidence.

METHODS AND RESULTS

We enrolled 50 OHS patients and 50 sex- and age-matched obese subjects as control. Study population underwent cardiologic evaluation and polysomnography before enrollment, at 1- and 6-month follow-ups after CPAP therapy. The OHS group showed a significant increase in inter-atrial (35.2 ± 8 milliseconds vs. 20.1 ± 2.7 milliseconds, P < 0.0001), intra-left (30.5 ± 7.2 milliseconds vs. 16.5 ± 2 milliseconds, P < 0.0001), and intra-right atrial electromechanical delays (AEMD)(24.8 ± 10 milliseconds vs. 15 ± 2.6 milliseconds, P < 0.0001) as well as in Pmax (130 ± 7.4 milliseconds vs. 97 ± 7.2 milliseconds, P = 0.002) and PD (56.5 ± 8.5 milliseconds vs. 31 ± 7.2 milliseconds, P = 0.002) compared to the control group. Significant improvement was noted after 6 months of CPAP therapy in inter-atrial (35.2 ± 8 milliseconds vs. 24.5 ± 6.3 milliseconds, P < 0.0001), intra-left (30.5 ± 7.2 milliseconds vs. 20.6 ± 5 milliseconds, P = 0.003), and intra-right AEMD (24.8 ± 10 milliseconds vs. 17 ± 7.5 milliseconds, P < 0.0001), as well as in Pmax (130 ± 7.4 milliseconds vs. 95 ± 10 milliseconds, P < 0.0001) and in PD (56.5 ± 8.5 milliseconds vs. 32.5 ± 6 milliseconds, P < 0.0001) in the OHS group. External loop recorder monitoring detected paroxysmal AF in 19 OHS patients (38%) with significant reduction in paroxysmal AF episodes (12 ± 6 vs. 47 ± 12, P < 0.0001) after 6-month CPAP therapy.

CONCLUSION

Our findings showed a significant increase of electrocardiographic and echocardiographic indexes of atrial conduction heterogeneity in OHS patients. The CPAP therapy, having a positive impact on atrial conduction time, seems to reduce AF incidence in OHS patients.

Use of a Patient-Activated Event Recording System in Patients with Tachycardic Palpitations: How Long to Follow Up?

INTRODUCTION

Palpitations are a common symptom causing patients to consult a cardiologist, yet diagnosing a potential cardiac origin can be difficult. In patients with a nondiagnostic Holter-ECG, external loop-recorders are an additional tool to diagnose the clinical arrhythmia in these patients. The aim of our study was to evaluate the additional value of an external, patient-activated loop recorder and to determine the optimal time of follow up needed to achieve a symptom-rhythm correlation with the device.

METHODS AND RESULTS

A total of 1404 patients presented to our outpatient clinic between November 2011 and November 2014 for first time evaluation of symptomatic arrhythmias. Of a total of 91 patients were included (age 43.6±18.1; 69.2% female) in the study. All patients presented with tachycardic palpitations and a 48-hour Holter-ECG that did not detect relevant arrhythmias. All patients were given a "leadless" patient-activated event-recording system and regular follow-up visits were scheduled after 3, 6, and 12 months. Within a maximum follow-up time of 1 year, 72 patients (79.1%) recorded at least one ECG with the device. Of the recorded ECGs, 51% were recorded within the first week after the device was handed out. This figure rises to 80% and 93% after 1 and 2 months. The last recording was after 174 days.

CONCLUSION

For patients with tachycardic palpitations, the external "leadess" event recorders are effective in achieving a symptom-rhythm correlation. A follow up of 2 months will suffice to establish a diagnosis in a large majority of this patient group.

Use of event recorders and loop recorders in clinical practice: results of the European Heart Rhythm Association Survey

Several kinds of electrocardiogram monitoring systems are now available in the clinical practice. The aim of this European Heart Rhythm Association (EHRA) survey was to assess the use of different monitoring techniques in the evaluation of patients with unexplained syncope, palpitations, and in those with established diagnosis of atrial fibrillation. Forty-five centres in Europe answered the questionnaire and the majority (78%) were university hospitals. The answers showed a discrepancy between the recommended use of implantable loop recorders (ILRs) in patients with unexplained syncope and the use of this device in clinical practice. In most of the cases only a minority of patients (<20%) seemed to actually receive an ILR as a part of the diagnostic process in accordance to the current guidelines. Holter monitoring systems and external loop recorders seemed to be the preferred monitoring techniques both in patients with recurrent palpitations and in those with established diagnosis of atrial fibrillation.

Diagnostic yield of patch ambulatory electrocardiogram monitoring in children (from a national registry)

The diagnostic yield of continuous electrocardiographic (ECG) monitoring in children for periods longer than a Holter monitor is unclear. The aim of this study was to characterize diagnostic yield, arrhythmia type, and time to first arrhythmia using a clinical repository of national ambulatory ECG data in children. A cross-sectional study was performed in 3,209 consecutive children receiving a 14-day adhesive patch monitor (Zio Patch) for clinical indications from January 2011 to December 2013. Of the 3,209 children (56% female, mean age 12.5 ± 4.4 years, range 1 month to 17 years), 390 had arrhythmias detected, making the diagnostic yield 12.2%. Of these, 137 patients (4.3%) had arrhythmias deemed clinically significant to warrant urgent physician notification. The most frequent indications for monitoring were palpitations (n = 1,138 [35.5%]), syncope (n = 450 [14.0%]), unspecified tachycardia (n = 291 [9.1%]), supraventricular tachycardia (n = 264 [8.2%]), and chest pain (n = 261 [8.1%]). Arrhythmias were detected in 10.0% of patients with palpitations, 6.7% of patients with syncope, 14.8% of patients with tachycardia, 22.7% of patients with supraventricular tachycardia, and 6.5% of patients with chest pain. The mean times to first detected and first symptom-triggered arrhythmias were 2.7 ± 3.0 and 3.3 ± 3.3 days, respectively. Forty-four percent of first detected arrhythmias and 50.4% of the first symptom-triggered arrhythmias occurred beyond 48 hours of monitoring. In conclusion, the diagnostic yield of continuous ECG patch monitoring in children was substantial beyond 48 hours and should be considered in children who are candidates for longer term ECG 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.

Factors predicting an arrhythmogenic superior vena cava in atrial fibrillation ablation: insight into the mechanism

BACKGROUND

The superior vena cava (SVC) is an infrequent but important source of atrial fibrillation (AF), but is not always easy to identify.

OBJECTIVE

This study aimed to identify predictors of an arrhythmogenic SVC (a-SVC) in patients undergoing AF ablation.

METHODS

Eight hundred thirty-six consecutive patients undergoing AF ablation were analyzed. All patients underwent pulmonary vein antrum isolation during the index procedure. An a-SVC, defined as SVC-triggered AF and an SVC associated with the maintenance of AF, was evaluated by mapping catheters throughout the procedure.

RESULTS

An a-SVC was identified in 44 patients (5.3%) during a total of 1063 procedures. Patients with an a-SVC were younger, less obese, and had a smaller left atrial (LA) size and more paroxysmal AF than those without an a-SVC. The presence of structural heart disease and hypertension was lower, and the coexistence of spontaneous common atrial flutter (AFL) before or during the index procedure was higher in those with an a-SVC than in those without. A multiple logistic regression analysis revealed that the LA size (odds ratio 0.93; 95% confidence interval 0.88-0.99; P = .038) and coexistence of spontaneous common AFL (odds ratio 2.01; 95% confidence interval 1.00-4.02; P = .048) were independent predictors identifying an a-SVC. Although 19 patients (43.2%) required repeat procedures, 39 (88.6%) were free from any atrial tachyarrhythmias without antiarrhythmic drugs at a median of 16.5 months (25th-75th percentiles 9.0-27.0 months) after a mean of 1.5 ± 0.7 procedures.

CONCLUSION

A smaller LA size and coexistence of spontaneous common AFL were independent predictors of an a-SVC in the context of AF ablation.