Simplified electrocardiogram sampling maintains high diagnostic capability for atrial fibrillation: implications for opportunistic atrial fibrillation screening in primary care. Performance of a New Leadless Implantable Cardiac Monitor in Detecting and Quantifying Atrial Fibrillation Results of the XPECT Trial EARLY: a pilot study on early diagnosis of atrial fibrillation in a primary healthcare centre. A randomised controlled trial and cost-effectiveness study of systematic screening (targeted and total population screening) versus routine practice for the detection of atrial fibrillation in people aged 65 and over. The SAFE study. Assessment of Remote Heart Rhythm Sampling Using the AliveCor Heart Monitor to Screen for Atrial Fibrillation: The REHEARSE-AF Study Long-term risk of recurrent atrial fibrillation as documented by an implantable monitoring device: implications for optimal patient care. Atrial fibrillation and paroxysmal atrial fibrillation detection in patients with acute ischemic stroke. Screening for atrial fibrillation in general practice: a national, cross-sectional study of an innovative technology.
AIMS Atrial fibrillation ( AF ) is a major cause of morbidity , mortality , and health re source consumption . However , as many patients with chronic AF are asymptomatic , rapid , accurate opportunistic screening is needed in primary care to detect AF . Conventional electrocardiogram ( ECG ) technology is too clumsy and time consuming for mass opportunistic screening , thus technology that allows easy , rapid , yet accurate AF screening is required . To address this requirement a prototype h and -held electrode assembly was developed . We hypothesized that a 6-lead frontal-plane ECG acquired from this apparatus in a seated , clothed patient would be as accurate at detecting AF as conventional 12-lead ECG in the undressed , supine patient ( the ' gold st and ard ' ) . METHODS AND RESULTS Electrocardiograms were obtained from 78 patients with AF and 79 with sinus rhythm ( SR ) . All had a  conventional 12-lead ECG  , a 6-lead ECG from conventionally positioned limb electrodes , a supine 6-lead recording using the prototype recorder placed on the lower thorax/upper abdomen , and a 6-lead prototype recording in the seated patient , the latter with loosened clothing only . Electrocardiograms were r and omly and blindly assessed by two cardiologists for ( i ) diagnosis of AF vs. SR and ( ii ) tracing quality ( subjectively assessed as good , adequate , or bad ) . Compared with conventional 12-lead ECG recordings , all ' new ' recording methods performed satisfactorily with sensitivities ≥90 % ( 90 - 99 % ) , specificities ≥94 % ( 94 - 100 % ) , positive predictive values ≥94 % ( 94 - 100 % ) , negative predictive values ≥90 % ( 90 - 99 % ) , and accuracies ≥93 % ( 93 - 99 % ) . Tracing quality was higher in conventional 12-lead recordings ( 71 and 80 % were assessed as good by the two observers ) compared with conventional 6-lead ( 57 and 59 % ) , supine prototype ( 41 and 31 % ) , and sitting prototype ( 39 and 19 % ) . CONCLUSIONS Despite inferior electrocardiographic quality a 6-lead frontal plane ECG acquired by a simple prototype h and -held electrode assembly allowed reliable differentiation of AF from SR compared with st and ard 12-lead ECG Background —Current methods for detecting atrial fibrillation ( AF ) have limited diagnostic yield . Continuous monitoring with automatic arrhythmia detection and classification may improve detection of symptomatic and asymptomatic AF and subsequent patient treatment . The study purpose was to quantify the performance of the first implantable leadless cardiac monitor ( ICM ) with dedicated AF detection capabilities . Methods and Results — Patients ( n=247 ) with an implanted ICM ( Reveal XT , Medtronic Inc , Minneapolis , Minn ) who were likely to present with paroxysmal AF were selected . A special Holter device stored 46 hours of subcutaneously recorded ECG , ICM markers , and 2 surface ECG leads . The ICM  automatic arrhythmia classification was compared with the core laboratory classification of the surface ECG . Of the 206 analyzable Holter recordings collected , 76 ( 37 % ) contained at least 1 episode of core laboratory classified AF . The sensitivity , specificity , positive predictive value , and negative predictive value for identifying patients with any AF were 96.1 % , 85.4 % , 79.3 % , and 97.4 % , respectively . The AF burden measured with the ICM was very well correlated with the reference value derived from the Holter ( Pearson coefficient=0.97 ) . The overall accuracy of the ICM for detecting AF was 98.5 % . Conclusions —In this ICM validation study , the dedicated AF detection algorithm reliably detected the presence or absence of AF and the AF burden was accurately quantified . The ICM is a promising new diagnostic and monitoring tool for the clinician to treat AF patients independently of symptoms . Long-term studies are needed to evaluate the clinical benefits of the technology . Clinical Trial Registration — clinical trials.gov Identifier NCT00680927 AIM Atrial fibrillation ( AF ) is associated with high morbidity and mortality . Early diagnosis is likely to improve therapy and prognosis . The study objective was to evaluate the usefulness of a programme for early diagnosis of AF in patients from an urban primary care centre . METHODS AND RESULTS Participants were recruited from a r and omized sample of patients not diagnosed with AF but having relevant risk factors : age ≥ 65 years , ischaemic and /or valvular heart disease , congestive heart failure , hypertension , and /or diabetes . Patients were r and omly assigned to the intervention group ( IG ) or control group ( CG ) . The intervention included ( i ) initial visit with clinical history , electrocardiogram , and instruction about pulse palpation and warning signs and ( ii ) electrocardiogram every 6 months during a 2-year follow-up . The main endpoint of the study was the proportion of new cases diagnosed at 6 months . Secondary endpoints were number of new AF diagnoses and complications associated with the arrhythmia in both groups . A total of 928 patients were included ( 463 IG and 465 CG ) . At 6 months , AF was diagnosed in 8 IG patients and 1 CG patient ( 1.7 vs. 0.2 % , respectively , P = 0.018 ) . After 2 years of follow-up , 11 IG patients and 6 CG patients had newly diagnosed AF ( 2.5 vs. 1.3 % , respectively , P = 0.132 ) . Time to first diagnosis of AF was shorter in IG patients [ median ( inter-quartile range ) : 7 ( 192 ) days vs. 227 ( 188.5 ) days in CG , P = 0.029 ] . CONCLUSION The simple screening proposed could be useful for the early detection of AF in primary care OBJECTIVES To determine the most cost-effective method of screening for  atrial fibrillation ( AF ) in the population aged 65 years and over , as well as its prevalence and incidence in this age group . Also to evaluate the relative cost-effectiveness of different methods of recording and interpreting the electrocardiogram ( ECG ) within a screening programme . DESIGN Multicentred r and omised controlled trial . Purpose fully selected general practice s were r and omly allocated to 25 intervention practice s and 25 control practice s. SETTING Fifty primary care centres across the West Midl and s , UK . PARTICIPANTS Patients aged 65 years and over . INTERVENTIONS GPs and practice nurses in the intervention practice s received education on the importance of AF detection and ECG interpretation . Patients in the intervention practice s were r and omly allocated to systematic ( n = 5000 ) or opportunistic screening ( n = 5000 ) . Prospect i ve identification of pre-existing risk factors for AF within the screened population enabled comparison between targeted screening of people at higher risk of AF and total population screening . MAIN OUTCOME MEASURES AF detection rates in systematic ally screened and opportunistically screened population s in the intervention practice s were compared with AF detection rate in 5000 patients in the control practice s. The screening period was 12 months . RESULTS Baseline prevalence of AF was 7.2 % , with a higher prevalence in males ( 7.8 % ) and patients aged 75 years and over ( 10.3 % ) . The control population demonstrated higher baseline prevalence ( 7.9 % ) than either the systematic ( 6.9 % ) or opportunistic ( 6.9 % ) intervention population . In the control population 47 new cases were detected ( incidence 1.04 % per year ) . In the opportunistic arm 243 patients without a baseline diagnosis of AF were found to have an irregular pulse , with 177 having an ECG , yielding 31 new cases ( incidence 0.69 % per year ) . A further 44 cases were detected outside the screening programme ( overall incidence 1.64 % per year ) . In the systematic arm 2357 patients had an ECG yielding 52 new cases ( incidence 1.1 % per year ) . Of these , 31 were detected by targeted screening and a further 21 by total population screening . A further 22 cases were detected outside the screening programme ( overall incidence 1.62 % per year ) . In terms of ECG interpretation , computerised decision support software ( CDSS ) gave a sensitivity of 87.3 % , a specificity of 99.1 % and a positive predictive value ( PPV ) of 89.5 % compared with the gold st and ard ( cardiologist reporting ) . GPs and practice nurses performed less well . The only difference in performance between intervention population s and controls was that practice nurses from the control arm performed less well than with intervention practice nurses on interpretation of limb-lead ( PPV 38.8 % versus 20.8 % ) and single-lead ( PPV 37.7 % versus 24.0 % ) ECGs . The within-trial economic evaluation results showed the lowest incremental cost to be for the opportunistic arm , with an incremental cost-effectiveness ratio of 337 pounds Sterling for each additional case detected compared to the control arm . Opportunistic screening dominated both more intensive screening strategies . Model-based analyses showed small differences in cost and quality -adjusted life-years for different methods and intensities of screening , but annual opportunistic screening result ed in the lowest number of ischaemic strokes and greatest proportion of cases of AF diagnosed . Probabilistic sensitivity results indicated that there was a probability of approximately 60 % that screening from the age of 65 years was cost-effective in both men and women . CONCLUSIONS The results of the study indicated that in terms of a screening programme for atrial fibrillation in patients 65 and over , the only strategy that improved on routine practice was opportunistic screening , model-based analyses indicated that there was a probability of approximately 60 % of annual opportunistic screening being cost effective . It is suggested that the following topics are worthy of further investigation : the effect of the implementation of a screening programme for AF on the uptake and maintenance of anticoagulation in patients aged 65 years and over ; an evaluation of the role of CDSS in the diagnosis of cardiac arrythmias ; the best method for routinely detecting paroxysmal AF ; ways of improving healthcare professionals ' performance in ECG interpretation ; development of a robust economic model to incorporate data on new therapeutic agents for use as thromboprophylactic agents for patients with AF , and an evaluation of the relative risk of stroke for patients with incident as opposed to prevalent AF Background : Asymptomatic atrial fibrillation ( AF ) is increasingly common in the aging population and implicated in many ischemic strokes . Earlier identification of AF with appropriate anticoagulation may decrease stroke morbidity and mortality . Methods : We conducted a r and omized controlled trial of AF screening using an AliveCor Kardia monitor attached to a WiFi-enabled iPod to obtain ECGs ( iECGs ) in ambulatory patients . Patients ≥65 years of age with a CHADS-VASc score ≥2 free from AF were r and omized to the iECG arm or routine care ( RC ) . iECG participants acquired iECGs twice weekly over 12 months ( plus additional iECGs if symptomatic ) onto a secure study server with overread by an automated AF detection algorithm and by a cardiac physiologist and /or consultant cardiologist . Time to diagnosis of AF was the primary outcome measure . The overall cost of the devices , ECG interpretation , and patient management were captured and used to generate the cost per AF diagnosis in iECG patients . Clinical events and patient attitudes/experience were also evaluated . Results : We studied 1001 patients ( 500 iECG , 501 RC ) who were 72.6±5.4 years of age ; 534 were female . Mean CHADS-VASc score was 3.0 ( heart failure , 1.4 % ; hypertension , 54 % ; diabetes mellitus , 30 % ; prior stroke/transient ischemic attack , 6.5 % ; arterial disease , 15.9 % ; all CHADS-VASc risk factors were evenly distributed between groups ) . Nineteen patients in the iECG group were diagnosed with AF over the 12-month study period versus 5 in the RC arm ( hazard ratio , 3.9 ; 95 % confidence interval=1.4–10.4 ; P=0.007 ) at a cost per AF diagnosis of $ 10 780 ( £ 8255 ) . There was a similar number of stroke/transient ischemic attack/systemic embolic events ( 6 versus 10 , iECG versus RC ; hazard ratio=0.61 ; 95 % confidence interval=0.22–1.69 ; P=0.34 ) . The majority of iECG patients were satisfied with the device , finding it easy to use without restricting activities or causing anxiety . Conclusions : Screening with twice-weekly single-lead iECG with remote interpretation in ambulatory patients ≥65 years of age at increased risk of stroke is significantly more likely to identify incident AF than RC over a 12-month period . This approach is also highly acceptable to this group of patients , supporting further evaluation in an appropriately powered , event-driven clinical trial . Clinical Trial Registration : URL : https://www.is rct n.com . Unique identifier : IS RCT N10709813 OBJECTIVES The present study determined the incidence and time course of atrial fibrillation ( AF ) recurrences  in patients with a history of AF and fitted with an implantable monitoring device .  BACKGROUND The long-term risk of undetected recurrence of AF in patients receiving stable antiarrhythmic therapy remains uncertain . METHODS In 110 patients with a class I indication for physiologic pacing and a history of AF , a pacemaker with dedicated functions for AF detection and electrogram storage was implanted , and antiarrhythmic drug treatment was optimized . Patients were regularly followed up with evaluation of AF-related symptoms , a  resting electrocardiogram ( ECG ) , and  interrogation of device memory .  The incidence of AF recurrences lasting > 48 h in asymptomatic patients presenting in sinus rhythm ( SR ) at the respective follow-up visit constituted the primary end point of this prospect i ve study . RESULTS During 19 + /- 11 months , 678 follow-up visits were performed . Atrial fibrillation was documented in 51 patients ( 46 % ) by ECG recording and in 97 patients ( 88 % ) by a review of stored electrograms ( p < 0.0001 ) . Device interrogation revealed AF recurrences lasting > 48 h in 50 patients , 19 of whom ( 38 % ) were completely asymptomatic and in SR at subsequent follow-up . In 11 ( 16 % ) of 67 patients with device-confirmed freedom from AF for > or =3 months , AF lasting > 48 h recurred subsequently . CONCLUSIONS This prospect i ve study demonstrates a high incidence of recurrent AF despite optimized antiarrhythmic therapy . Of particular note , AF relapses > 48 h remained totally asymptomatic in a significant proportion of patients . Freedom from AF for > or =3 months did not preclude subsequent long-lasting AF recurrence BACKGROUND Studies about continuous electrocardiographic ( ECG ) monitoring in detection of paroxysmal atrial fibrillation ( PAF ) in Asian patients with acute ischemic stroke are very limited . We looked for the prevalence and associated factors of atrial fibrillation ( AF ) and PAF in Thai patients with acute ischemic stroke . METHODS In all , 204 patients with acute ischemic stroke were prospect ively included .  Snapshot 12-lead ECG and continuous ECG monitoring for at least the first 24 hours were performed . Multivariate analyses were performed to find out the associated factors of AF and PAF . RESULTS AF was diagnosed in 31 patients ( 15 % ) and PAF in 15 patients ( 7 % ) . Twelve and 3 patients with PAF were diagnosed by continuous ECG monitoring and snapshot 12-lead ECG , respectively . Mean duration of continuous ECG monitoring and mean time to detect PAF were 55 and 23 hours , respectively . Multivariate analysis revealed that age of 70 years or older ( odds ratio [ OR ] 3.52 , 95 % confidence interval [ CI ] 1.68 - 7.35 , P = .001 ) and heart diseases ( OR 4.26 , 95 % CI 1.14 - 15.95 , P = .031 ) were associated with AF and PAF . CONCLUSIONS AF/PAF was one of the common causes of ischemic stroke in Thai patients . Most PAF was detected by continuous ECG monitoring . Snapshot 12-lead ECG and continuous ECG monitoring should be recommended in all patients with acute ischemic stroke BACKGROUND To test the use of three lead monitoring as a screening tool for  atrial fibrillation ( AF )  in general practice . AF is responsible for up to a quarter of all strokes and is often asymptomatic until a stroke occurs . METHODS 26 r and omly selected general practice s identified 80 r and omly selected patients aged 70 or older from their data base and excluded those known to have AF , those with clinical issues or who had not attended for three years . Up to 40 eligible patients / practice were invited to attend for screening . A 2min three-lead ECG was recorded and collected central ly for expert cardiology assessment . Risk factor data was gathered . OUTCOMES ( i ) point prevalence of AF , ( ii ) proportion of ECG tracings which were adequate for interpretation , ( iii ) uptake rate by patients and ( iv ) acceptability of the screening process to patients and staff ( reported separately ) . RESULTS Of 1447 current patients , 1003 were eligible for inclusion , 639 ( 64 % ) agreed to take part in screening and 566 ( 56 % ) completed screening . The point prevalence rate for AF was 10.3%-2.1 % new cases ( 12 of 566 who were screened ) and 9.5 % existing cases ( 137 of 1447 eligible patients ) . Only four of 570 ( 0.7 % ) screening visits did not record a usable ECG and 11 ( 2.6 % ) three lead ECGs required a clarifying 12 lead ECG . CONCLUSIONS Three lead screening for AF is feasible , effective and offers an alternative to pulse taking or 12 lead ECGs . The availability of this technology may facilitate more effective screening , leading to reduced stroke incidence
Kardia Mobile ( AliveCor Ltd , Mountain View , CA , USA ) is the most cost-effective option in a full incremental analysis .
Single time point lead-I ECG devices for the detection of AF in people with signs or symptoms of AF and an irregular pulse appear to be a cost-effective use of NHS re sources compared with MPP followed by a 12-lead ECG in primary or secondary care , given the assumptions used in the base-case model .
BACKGROUND Atrial fibrillation ( AF ) is the most common type of cardiac arrhythmia and is associated with an increased risk of stroke and congestive heart failure .
Lead-I electrocardiogram ( ECG ) devices are h and held instruments that can be used to detect AF at a single time point in people who present with relevant signs or symptoms .
OBJECTIVE To assess the diagnostic test accuracy , clinical impact and cost-effectiveness of using single time point lead-I ECG devices for the detection of AF in people presenting to primary care with relevant signs or symptoms , and who have an irregular pulse compared with using manual pulse palpation ( MPP ) followed by a 12-lead ECG in primary or secondary care .