Diagnostic yield of patient-activated loop recorders for detecting heart rhythm abnormalities in general practice: a randomised clinical trial

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 Accuracy of a Smartphone-Operated, Single-Lead Electrocardiography Device for Detection of Rhythm and Conduction Abnormalities in Primary Care

PURPOSE

To validate a smartphone-operated, single-lead electrocardiography (1L-ECG) device (AliveCor KardiaMobile) with an integrated algorithm for atrial fibrillation (AF) against 12-lead ECG (12L-ECG) in a primary care population.

METHODS

We recruited consecutive patients who underwent 12L-ECG for any nonacute indication. Patients held a smartphone with connected 1L-ECG while local personnel simultaneously performed 12L-ECG. All 1L-ECG recordings were assessed by blinded cardiologists as well as by the smartphone-integrated algorithm. The study cardiologists also assessed all 12L-recordings in random order as the reference standard. We determined the diagnostic accuracy of the 1L-ECG in detecting AF or atrial flutter (AFL) as well as any rhythm abnormality and any conduction abnormality with the simultaneously performed 12L-ECG as the reference standard.

RESULTS

We included 214 patients from 10 Dutch general practices. Mean ± SD age was 64.1 ± 14.7 years, and 53.7% of the patients were male. The 12L-ECG diagnosed AF/AFL, any rhythm abnormality, and any conduction abnormality in 23, 44, and 28 patients, respectively. The 1L-ECG as assessed by cardiologists had a sensitivity and specificity for AF/AFL of 100% (95% CI, 85.2%-100%) and 100% (95% CI, 98.1%-100%). The AF detection algorithm had a sensitivity and specificity of 87.0% (95% CI, 66.4%-97.2%) and 97.9% (95% CI, 94.7%-99.4%). The 1L-ECG as assessed by cardiologists had a sensitivity and specificity for any rhythm abnormality of 90.9% (95% CI, 78.3%-97.5%) and 93.5% (95% CI, 88.7%-96.7%) and for any conduction abnormality of 46.4% (95% CI, 27.5%-66.1%) and 100% (95% CI, 98.0%-100%).

CONCLUSIONS

In a primary care population, a smartphone-operated, 1L-ECG device showed excellent diagnostic accuracy for AF/AFL and good diagnostic accuracy for other rhythm abnormalities. The 1L-ECG device was less sensitive for conduction abnormalities.

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.

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.

Systematic screening for the detection of atrial fibrillation

BACKGROUND

Atrial fibrillation (AF), the most common arrhythmia in clinical practice, is a leading cause of morbidity and mortality. Screening for AF in asymptomatic patients has been proposed as a way of reducing the burden of the disease by detecting people who would benefit from prophylactic anticoagulation therapy before the onset of symptoms. However, for screening to be an effective intervention, it must improve the detection of AF and provide benefit for those detected earlier as a result of screening.

OBJECTIVES

This review aims to answer the following questions.Does systematic screening increase the detection of AF compared with routine practice? Which combination of screening population, strategy and test is most effective for detecting AF compared with routine practice? What safety issues and adverse events may be associated with individual screening programmes? How acceptable is the intervention to the target population? What costs are associated with systematic screening for AF?

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and EMBASE (Ovid) up to 11 November 2015. We searched other relevant research databases, trials registries and websites up to December 2015. We also searched reference lists of identified studies for potentially relevant studies, and we contacted corresponding authors for information about additional published or unpublished studies that may be relevant. We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials comparing screening for AF with routine practice in people 40 years of age and older were eligible. Two review authors (PM and CT) independently selected trials for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors (PM and CT) independently assessed risk of bias and extracted data. We used odds ratios (ORs) and 95% confidence intervals (CIs) to present results for the primary outcome, which is a dichotomous variable. As we identified only one study for inclusion, we performed no meta-analysis. We used the GRADE (Grades of Recommendation, Assessment, Development and Evaluation Working Group) method to assess the quality of the evidence and GRADEPro to create a 'Summary of findings' table.

MAIN RESULTS

One cluster-randomised controlled trial met the inclusion criteria for this review. This study compared systematic screening (by invitation to have an electrocardiogram (ECG)) and opportunistic screening (pulse palpation during a general practitioner (GP) consultation for any reason, followed by an ECG if pulse was irregular) versus routine practice (normal case finding on the basis of clinical presentation) in people 65 years of age or older.Results show that both systematic screening and opportunistic screening of people over 65 years of age are more effective than routine practice (OR 1.57, 95% CI 1.08 to 2.26; and OR 1.58, 95% CI 1.10 to 2.29, respectively; both moderate-quality evidence). We found no difference in the effectiveness of systematic screening and opportunistic screening (OR 0.99, 95% CI 0.72 to 1.37; low-quality evidence). A subgroup analysis found that systematic screening and opportunistic screening were more effective in men (OR 2.68, 95% CI 1.51 to 4.76; and OR 2.33, 95% CI 1.29 to 4.19, respectively) than in women (OR 0.98, 95% CI 0.59 to 1.62; and OR 1.2, 95% CI 0.74 to 1.93, respectively). No adverse events associated with screening were reported.The incremental cost per additional case detected by opportunistic screening was GBP 337, compared with GBP 1514 for systematic screening. All cost estimates were based on data from the single included trial, which was conducted in the UK between 2001 and 2003.

AUTHORS' CONCLUSIONS

Evidence suggests that systematic screening and opportunistic screening for AF increase the rate of detection of new cases compared with routine practice. Although these approaches have comparable effects on the overall AF diagnosis rate, the cost of systematic screening is significantly greater than the cost of opportunistic screening from the perspective of the health service provider. Few studies have investigated effects of screening in other health systems and in younger age groups; therefore, caution needs to be exercised in relation to transferability of these results beyond the setting and population in which the included study was conducted.Additional research is needed to examine the effectiveness of alternative screening strategies and to investigate the effects of the intervention on risk of stroke for screened versus non-screened populations.

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.

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.

Effectiveness of systematic screening for the detection of atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is a leading cause of morbidity and mortality. Screening for AF in asymptomatic patients has been proposed as a way of reducing the burden of the disease by detecting people who would benefit from prophylactic anticoagulation therapy prior to the onset of symptoms. However, for screening to be an effective intervention it must improve the detection of AF and provide benefit for those who are detected earlier as a result of screening.

OBJECTIVES

The primary objective of this review was to examine whether screening programmes increase the detection of new cases of AF compared to routine practice. The secondary objectives were to identify which combination of screening strategy and patient population is most effective, as well as assessing any safety issues associated with screening, its acceptability within the target population and the costs involved.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, MEDLINE (Ovid) and EMBASE (Ovid) up to March 2012. Other relevant research databases, trials registries and websites were searched up to June 2012. Reference lists of identified studies were also searched for potentially relevant studies and we contacted corresponding authors for information about additional published or unpublished studies that may be relevant. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials, controlled before and after studies and interrupted time series studies comparing screening for AF with routine practice in people aged 40 years and over were eligible. Two authors (PM, CT or MF) independently selected the trials for inclusion.

DATA COLLECTION AND ANALYSIS

Assessment of risk of bias and data extraction were performed independently by two authors (PM, CT). Odds ratios (OR) and 95% confidence intervals (CI) were used to present the results for the primary outcome, which is a dichotomous variable. Since only one included study was identified, no meta-analysis was performed.

MAIN RESULTS

One cluster randomised controlled trial met the inclusion criteria for this review. This study compared systematic screening (by invitation to have an electrocardiogram (ECG)) and opportunistic screening (pulse palpation during a general practitioner (GP) consultation for any reason followed by an ECG if pulse was irregular) to routine practice (normal case finding on the basis of clinical presentation) in people aged 65 years or older. The risk of bias in the included study was judged to be low.Both systematic and opportunistic screening of people over the age of 65 years are more effective than routine practice (OR 1.57, 95% CI 1.08 to 2.26 and OR 1.58, 95% CI 1.10 to 2.29, respectively). The number needed to screen in order to detect one additional case compared to routine practice was 172 (95% CI 94 to 927) for systematic screening and 167 (95% CI 92 to 806) for opportunistic screening. Both systematic and opportunistic screening were more effective in men (OR 2.68, 95% CI 1.51 to 4.76 and OR 2.33, 95% CI 1.29 to 4.19, respectively) than in women (OR 0.98, 95% CI 0.59 to 1.62 and OR 1.2, 95% CI 0.74 to 1.93, respectively). No data on the effectiveness of screening in different ethnic or socioeconomic groups were available. There were insufficient data to compare the effectiveness of screening programmes in different healthcare settings.Systematic screening was associated with a better overall uptake rate than opportunistic screening (53% versus 46%) except in the ≥ 75 years age group where uptake rates were similar (43% versus 42%). In both screening programmes men were more likely to participate than women (57% versus 50% in systematic screening, 49% versus 41% in opportunistic screening) and younger people (65 to 74 years) were more likely to participate than people aged 75 years and over (61% versus 43% systematic, 49% versus 42% opportunistic). No adverse events associated with screening were reported.The incremental cost per additional case detected by opportunistic screening was GBP 337, compared to GBP 1514 for systematic screening. All cost estimates were based on data from the single included trial, which was conducted in the UK between 2001 and 2003.

AUTHORS' CONCLUSIONS

Systematic and opportunistic screening for AF increase the rate of detection of new cases compared with routine practice. While both approaches have a comparable effect on the overall AF diagnosis rate, the cost of systematic screening is significantly more than that of opportunistic screening from the perspective of the health service provider. The lack of studies investigating the effect of screening in other health systems and younger age groups means that caution needs to be exercised in relation to the transferability of these results beyond the setting and population in which the included study was conducted.Additional research is needed to examine the effectiveness of alternative screening strategies and to investigate the effect of the intervention on the risk of stroke for screened versus non-screened populations.

Validation of the 3-lead tele-ECG versus the 12-lead tele-ECG and the conventional 12-lead ECG method in older people

We compared the diagnostic accuracy of 3-lead tele-ECGs to both 12-lead tele-ECGs and a conventional 12-lead ECG device (the gold standard). The subjects were older people (n = 107) with a mean age of 66 years. The overall agreement between two cardiologists on interpreting the 3-lead tele-ECG recordings was 97% (kappa = 0.96, P < 0.001) and it was 91% for the 12-lead tele-ECGs (kappa = 0.90, P < 0.001). We also found excellent agreement on the interpretation of the 3-lead tele-ECGs compared to the gold standard: 98% (kappa = 0.96, P < 0.001) and for the 12-lead tele-ECG compared to the gold standard: 98% (kappa = 0.96, P < 0.001). Bland-Altman plots showed that the apparent differences between the techniques were not clinically relevant. The use of a 3-lead tele-ECG device may be useful for reducing the delay in treating specific heart disease conditions, e.g. in older people affected by chronic heart disease who need frequent ECG monitoring.

How usual is usual care in pragmatic intervention studies in primary care? An overview of recent trials

BACKGROUND

Because pragmatic trials are performed to determine if an intervention can improve current practice, they often have a control group receiving 'usual care'. The behaviour of caregivers and patients in this control group should be influenced by the actions of researchers as little as possible. Guidelines for describing the composition and management of a usual care control group are lacking.

AIM

To explore the variety of approaches to the usual care concept in pragmatic trials, and evaluate the influence of the study design on the behaviour of caregivers and patients in a usual care control group.

DESIGN OF STUDY

Review of 73 pragmatic trials in primary care with a usual care control group published between January 2005 and December 2009 in the British Medical Journal, the British Journal of General Practice, and Family Practice. Outcome measures were: description of the factors influencing caregiver and patients in a usual care control group related to an individual randomised design versus cluster randomisation.

RESULTS

In total, 38 individually randomised trials and 35 cluster randomised trials were included. In most trials, caregivers had the freedom to treat control patients according to their own insight; in two studies, treatment options were restricted. Although possible influences on the behaviour of control caregivers and control patients were more often identified in individually randomised trials, these influences were also present in cluster randomised trials. The description of instructions and information provided to the control group was often insufficient, which made evaluation of the trials difficult.

CONCLUSION

Researchers in primary care medicine should carefully consider the design of a usual care control group, especially with regard to minimising the risk of study-induced behavioural change. It is recommended that an adequate description of the information is provided to control caregivers and control patients. A proposal is made for an extension to the CONSORT statement that requires authors to specify details of the usual care control group.

Efficacy of diagnostic tools for detecting cardiac arrhythmias: systematic literature search

BACKGROUND/OBJECTIVES

Symptoms suggestive of cardiac arrhythmias are a challenge to the diagnosis. Physical examination and a 12-lead ECG are of limited value, as rhythm disturbances are frequently of a paroxysmal nature. New technologies facilitate a more accurate diagnosis. The objective of this study was to review the medical literature in an effort to define a guide to rational diagnostic testing.

METHODS

Primary studies on the use of a diagnostic tool in the evaluation of palpitations were searched in MEDLINE, and EMBASE with an additional reference check.

RESULTS

TWO TYPES OF STUDIES WERE FOUND: descriptive and experimental studies, which compared the yield of two or more devices or diagnostic strategies. Holter monitors seemed to have less diagnostic yield (33 to 35%) than event recorders. Automatically triggered recorders detect more arrhythmias (72 to 80%) than patient-triggered devices (17 to 75%). Implantable devices are used for prolonged monitoring periods in patients with infrequent symptoms or unexplained syncope.

CONCLUSION

The choice of the device depends on the characteristics of the symptoms and the patient. Due to methodological shortcomings of the included studies no evidence-based diagnostic strategy can be proposed. (Neth Heart J 2010;18:543-51.).

Frequency of serious arrhythmias detected with ambulatory cardiac telemetry

Ambulatory cardiac telemetry has been shown to be effective in establishing diagnoses in patients with suspected arrhythmias. A critical component of ambulatory telemetry is the immediate transfer of rhythm information to a central monitoring station without requiring patient action. The frequency with which potentially life-threatening events are detected using ambulatory telemetry has not previously been evaluated in a large patient population. All patients (n = 26,438) who underwent monitoring from April to December 2008 at a single service provider formed the patient population of this study. Arrhythmic events noted in these patients were defined as those requiring physician notification and those that represented potentially life-threatening arrhythmias. Of the 26,438 patients included in the study, 5,459 (21%) had arrhythmic events meeting physician notification criteria during a mean monitoring period of 21 days. Of these, 262 patients (1%) had arrhythmic events that could potentially be classified as emergent. These included 120 patients with wide complex tachycardia > or = 15 beats at > or = 120 beats/min, 100 patients with pauses > or = 6 seconds, and 42 patients with sustained heart rates <30 beats/min. An additional 704 patients (3%) had narrow complex tachycardia > or = 180 beats/min at rest. In conclusion, approximately 1% of patients who underwent ambulatory telemetry for routine clinical indications experienced life-threatening arrhythmic events over a 3-week monitoring period. Ambulatory cardiac telemetry could be potentially lifesaving in this group of patients.

Continuous event recorders did not affect anxiety or quality of life in patients with palpitations

OBJECTIVES

Palpitations can generate feelings of anxiety and decrease quality of life (QoL) due to fear of a cardiac abnormality. Continuous event recorders (CERs) have proven to be successful in diagnosing causes of palpitations but may affect patient QoL and anxiety. The aim is to determine anxiety and health-related (HR)-QoL and evaluate the burden of carrying a CER in general practice populations.

STUDY DESIGN AND SETTING

Patients (n=244) participated in a randomized trial. One group (n=127) carried a CER during 4 weeks. One hundred and seventeen patients formed the usual care (UC) group. State-Trait Anxiety Inventory (STAI) and the Short Form-36 (SF-36) were administered at study inclusion, after 1, 6 months.

RESULTS

At baseline, patients reported greater anxiety and lower QoL than healthy populations. The CER group had three times more cardiac diagnoses than the UC group. No differences were found between CER group and UC group at 6 weeks. At 6 months, the UC group showed QoL improvement and less anxiety compared to the CER group. Type of diagnosis had influence, but did not fully explain these differences.

CONCLUSION

A CER does not negatively influence anxiety or QoL. Better outcomes in the UC group might be attributed to less cardiac diagnosis and more emphasis on psychological well-being.

Diagnosing atrial fibrillation in general practice

The combination of a clinical history, clinical signs, and an ECG will pick up most cases

The diagnosis of cardiac arrhythmias: a prospective multi-center randomized study comparing mobile cardiac outpatient telemetry versus standard loop event monitoring

INTRODUCTION

Ambulatory electrocardiographic monitoring systems are frequently used in the outpatient evaluation of symptoms suggestive of a cardiac arrhythmia; however, they have a low yield in the identification of clinically significant but infrequent, brief, and/or intermittently symptomatic arrhythmias. The purpose of this study was to compare the relative value of a mobile cardiac outpatient telemetry system (MCOT) with a patient-activated external looping event monitor (LOOP) for symptoms thought to be due to an arrhythmia.

METHODS AND RESULTS

The study was a 17-center prospective clinical trial with patients randomized to either LOOP or MCOT for up to 30 days. Subjects with symptoms of syncope, presyncope, or severe palpitations who had a nondiagnostic 24-hour Holter monitor were randomized. The primary endpoint was the confirmation or exclusion of a probable arrhythmic cause of their symptoms. A total of 266 patients who completed the monitoring period were analyzed. A diagnosis was made in 88% of MCOT subjects compared with 75% of LOOP subjects (P = 0.008). In a subgroup of patients presenting with syncope or presyncope, a diagnosis was made in 89% of MCOT subjects versus 69% of LOOP subjects (P = 0.008). MCOT was superior in confirming the diagnosis of clinical significant arrhythmias, detecting such events in 55 of 134 patients (41%) compared with 19 of 132 patients (15%) in the LOOP group (P < 0.001).

CONCLUSIONS

MCOT provided a significantly higher yield than standard cardiac loop recorders in patients with symptoms suggestive of a significant cardiac arrhythmia.