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Background: Increasing prevalence of atrial fibrillation has a significant impact on health, society, and healthcare resource utilization, due to increased morbidity, mortality, risk of stroke, and reduction in quality of life. Early diagnosis allows for treatment initiation, a reduction in complications and associated costs, and so innovation to improve screening and enable easy access are needed Developments in digital technology have significantly contributed to the availability of screening tools. The single-lead electrocardiogram AliveCor (Mountainview, CA) device offers the opportunity to provide heart rhythm screening and has been used extensively in clinical practice and research studies., Methods: This review investigates the feasibility, validity, and utility of the AliveCor device as a tool for atrial fibrillation detection in clinical practice and in wider research. Databases searched included PUBMED, CINAHL, MEDLINE, and World of Science, plus grey literature search. Search terms related to atrial fibrillation, screening, and AliveCor with adults >18 years. Feasibility metrics were applied including process, resource, management, and scientific outcomes. Studies not written in the English language were excluded. Validity of AliveCor was explored by extracting sensitivity and specificity data from eligible studies and overall effectiveness analyzed by incorporating the above, with wider issues surrounding screening approaches, cost effectiveness and appropriateness of AliveCor as a screening tool., Results: The AliveCor device screening was reviewed in 11 studies matching inclusion criteria. Atrial fibrillation detection rates ranged from 0.8% to 36% and this largely correlated to the study population, where wider age inclusion and mass/population screening represented lower atrial fibrillation detection. Recruitment from higher-risk groups (older age, targeted localities, chronic disease) identified higher numbers with atrial fibrillation. Feasibility metrics demonstrated AliveCor as an effective tool of choice in terms of process, resources, and management. Duration of screening time had an impact on rates of atrial fibrillation detection. There was however significant heterogeneity between studies reviewed., Conclusion: The AliveCor device offers a convenient, valid, and feasible means of monitoring for atrial fibrillation. Further analysis of electrocardiograms produced by AliveCor may be necessary in some circumstances. The AliveCor electrocardiogram device can be successfully implemented into both opportunistic and systematic screening strategies for atrial fibrillation.

Introduction: Atrial fibrillation is often asymptomatic and un-diagnosed in the community resulting in an increased risk of heart failure and stroke to those patients. We evaluated the effectiveness, tolerability, and accuracy of a novel six-channel electrocardiogram digital-health screening device, the RhythmPad, for the detection of atrial fibrillation., Methods: Seven hundred and fifty-two participants attending the cardiology department were recruited. Two recordings were taken-a six-lead electrocardiogram using the RhythmPad device and a standard 12-lead electrocardiogram. Recorded traces were analyzed by two blinded cardiologists. The computer-generated automated diagnostic reports from both systems were also compared. Post-participation feedback was obtained from study participants using a three-part questionnaire., Results: The sensitivity of the six-lead electrocardiogram compared to the 12-lead electrocardiogram, analyzed by two blinded cardiologists, for the detection of normal sinus rhythm was 95.9%, with a specificity of 97.2%. The sensitivity for the detection of atrial fibrillation using the six-lead ECG was 93.4%, with specificity 96.8%. The six-lead automated diagnostic report had a sensitivity and specificity of 97.5% and 98.6%, respectively, for correctly diagnosing normal sinus rhythm. For the correct diagnosis of atrial fibrillation, the six-lead automated diagnostic report had a sensitivity and specificity of 95.4% and 98.8%, respectively. A total of 95.4% of participants found RhythmPad to be comfortable, with only 0.5% preferring the 12-lead ECG device in comparison to six-lead ECG acquisitions., Conclusion: The RhythmPad digital health device and its automated diagnostic report were highly accurate in detecting atrial fibrillation when compared to a standard 12-lead electrocardiogram., (© 2019 Wiley Periodicals, Inc.)

Background: Atrial fibrillation is a well-known independent risk factor for stroke yet there is no international consensus on guidelines regarding the introduction of anticoagulation in patients deemed at intermediate risk (e.g. CHA2DS2-VASc of 1). The evolution of cardiac biomarkers such as highly sensitive troponins and B-type natriuretic peptide as well as data on D-dimers, may offer incremental enhancements for personalized thromboembolism risk assessment. These markers provide prognostic data for risk of cardiovascular morbidities associated with atrial fibrillation and offer additional specificity for assessing stroke and thromboembolic risk. These assays may therefore enhance risk prognosis in atrial fibrillation alongside conventional stroke risk stratification tool patients. We seek to explore the application of personalised risk assessment using the biomarkers to aid the clinician treating the patient with atrial fibrillation deemed to be at intermediate risk of stroke., Conclusion: The stroke risk assessment of a patient with an intermediate risk of stroke (CHA2DS2- VASc score 1) may be improved by using cardiac biomarkers such as highly sensitive troponin, BNP and D-dimers. We explore the application of these biomarkers to provide personalised risk assessment to help a patient with AF decide on whether to commence anticoagulation., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Stroke is the most feared complication of atrial fibrillation but for over fifty years there has been no simple, effective preventative alternative to warfarin. The development of new risk algorithms such as CHADSVASC has resulted in more patients being recommended anticoagulation therapy. Fixed dose oral anticoagulation is a landmark in drug development for atrial fibrillation. The differences between the drugs are discussed and the trial data examined. As we enter this new frontier of therapy, there is no doubt that these drugs will transform the delivery of anticoagulation for patients with atrial fibrillation.

Digoxin has been used for hundreds of years to aid rate control in atrial fibrillation and as a positive inotrope in heart failure. Our familiarity with digoxin has allowed it to become easily prescribed even though there are data suggesting that use of digoxin may in fact result in increased mortality and pro-arrhythmia. Within this review we explain some of the outcome data associated with digoxin use to determine if it is time to take the gloves off and examine if we should still be using this drug in the 21st century., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: Current guidelines for transthoracic direct-current cardioversion (DCCV) of atrial fibrillation (AF) recommend a step-up energy protocol. The aim of this study was to compare such a protocol with a protocol involving a high initial energy shock, anteroposterior paddle position and reversal of shock polarity, on cardioversion efficacy, total energy delivery, use of sedation and patient tolerability., Methods: 261 patients (mean age 71+/-10 years, 62% male) referred for elective DCCV of persistent AF were enrolled. Patients were randomised to either protocol A: (1) 200 J anteroapical, (2) 360 J anteroapical, (3) 360 J anteroposterior; or protocol B: (1) 360 J anteroapical, (2) 360 J anteroposterior, and (3) 360 J posteroanterior. All procedures were performed under sedation with intravenous diazepam., Results: Protocol B improved shock success rates (protocol A first shock success rate=42%, protocol B=68%, p<0.001; protocol A second shock success rate=72%, protocol B 86%, p=0.006; protocol A third shock success rate=83%, protocol B=92%, p=0.03) and required fewer shocks to achieve sinus rhythm (1.3+/-0.6) compared with protocol A (1.6+/-0.7, p<0.001). There were no differences in cumulative energy used (protocol A 473+/-286 J, protocol B 436+/-273 J, p=0.24) or sedation requirements (protocol A diazepam 22.1+/-9.0 mg, protocol B 21.7+/-8.9 mg, p=0.75). Both protocols were equally well tolerated by patients., Conclusion: High initial energy increased success rates and decreased the number of shocks but resulted in similar cumulative energy delivery, sedation use and patient tolerability compared with a conventional step-up protocol.

Background: The effects of patient-activated atrial defibrillation on subclinical myocardial injury are unknown. Using biochemical markers, this study assessed the effect of a single internal atrial shock delivered by the implantable atrial defibrillator on myocardial damage, neurohormonal activation and inflammation., Methods: Twelve patients were implanted with a dual chamber defibrillator for the sole indication of drug refractory symptomatic persistent atrial fibrillation (AF). All had maximum defibrillation energy programmed to maximise the first shock success rate. Creatine kinase isoenzyme, troponin T, cortisol, catecholamines, C-reactive protein and brain natriuretic peptide were measured (i) during sinus rhythm, (ii) 8 h after onset of spontaneously occurring AF (before cardioversion) and (iii) 8 h following successful patient activated cardioversion., Results: There was no change in creatine kinase, troponin T, cortisol or C-reactive protein during AF or following internal cardioversion. Brain natriuretic peptide levels rose from a median value of 56 pg/ml during sinus rhythm (inter-quartile range 14-92 pg/ml) to 133 pg/ml during AF (30-262 pg/ml), p=0.002. There was a decrease 8 h after cardioversion to baseline (52 and 40-189 pg/ml), p=0.01. There were increases in serum adrenaline and noradrenaline levels during AF from 0.43 (0.12-0.61) to 0.58 pg/ml (0.39-0.80 pg/ml), p=0.002 and from 2.06 (1.61-2.59) to 2.83 nmol/l (2.43-3.46 nmol/l), p=0.02, respectively. These figures reverted to baseline levels 8 h post-cardioversion., Conclusions: Internal atrial defibrillation does not result in myocardial injury. The onset of AF results in sympathetic activation and increased brain natriuretic peptide levels, which resolve following restoration of sinus rhythm.

Background: To compare the acceptability and effectiveness of three pre-medication regimens for manually activated cardioversion of recurrent persistent atrial fibrillation., Methods: Eighteen patients implanted with the Jewel AF atrial defibrillator for drug-resistant persistent atrial fibrillation only were studied in an open-labelled randomised crossover study. Patients were assigned to sedation (S) with midazolam elixir, analgesia (A) with morphine sulphate or combination therapy (C) with dextromoramide and lorazepam. Pre-medication was taken up to 1 h before cardioversion. Patients rotated through each type of medication after undertaking at least one cardioversion. Visual analogue scales were completed immediately post-cardioversion and 24 h later for pain, anxiety and 'unpleasantness'. Higher scores represented a worse outcome., Results: After 2 years' follow-up, 238 cardioversions were performed with S, 17 with A and 35 with C. The mean immediate combined score for S (10.9, 95% confidence interval (CI) 8.2-13.6) was significantly lower than for A (17.3, 95% CI 15.1-19.5, P = 0.01) and for C (15.9, 95% CI 12.3-19.6, P = 0.02). All patients who used S chose it as the most favourable pre-medicant. All patients who used A found it the least acceptable., Conclusion: Sedation rather than analgesia enhanced the acceptability of manually activated atrial defibrillation., (Copyright 2003 Elsevier Ireland Ltd.)

Acceptability of the atrial defibrillator is partly limited by concerns about shock related anxiety and discomfort. Sedation and/or automatic cardioversion therapy during sleep may ease shock discomfort and improve patient acceptability. Three atrial cardioversion techniques were compared: patient-activated cardioversion with sedation, automatic night cardioversion with sedation, and automatic night cardioversion without sedation. Sedation was oral midazolam (15 mg). Fifteen patients aged 60 +/- 13 years were assigned each strategy randomly for three consecutive episodes of persistent atrial fibrillation requiring cardioversion. Patients completed questionnaires for multiple parameters immediately and again at 24 hours postcardioversion. Atrial cardioversion strategies with oral sedation (patient-activated and automatic) significantly reduced shock recall by 77% (P < 0.005), therapy dissatisfaction by 57%-71% (P < 0.03), shock discomfort by 61%-73% (P < 0.01), shock pain by 79%-83% (P < 0.001), and shock intensity by 73%-77% (P < 0.03), compared to automatic night cardioversion without sedation (P < 0.02). Atrial shock pain was short-lived and caused little disruption to the patients' daily routines. Automatic night cardioversion without sedation, resulted in sleep disturbances not seen with the other strategies (42% vs 0%, P < 0.001) as well as concerns about future pain or discomfort. Twelve patients (80%) chose patient-activated cardioversion with sedation as their preferred treatment, and three (20%) remainder chose automatic night cardioversion with sedation. Ninety percent of patients chose automatic night cardioversion without sedation as the least acceptable therapy. Sedation significantly increases atrial shock acceptability regardless of cardioversion method. Shocks without sedation are significantly less acceptable to patients using the atrial defibrillators.

With an aging population, atrial fibrillation is becoming an increasingly common cause of hospital admission. Patients with recurrent, symptomatic persistent atrial fibrillation often require repeated admissions to the hospital for cardioversion. The development of the atrial defibrillator has empowered such patients to take charge of their condition and perform cardioversion on themselves at home. This liberates them from the worry of hospitalization and can increase patient confidence. The implantation of an atrial defibrillator, however, has some disadvantages, and long-term use of the device exposes patients to some of the psychological adaptations that occur in recipients of implantable devices. This article discusses in depth the patient selection process, the implantation procedure, the use of the atrial defibrillator, and problems that can arise during long-term follow-up.

The aim of this study was to determine the effect of early patient activated cardioversion of atrial fibrillation (AF) using the atrial defibrillator on recurrence of AF. Fifteen patients, mean age 63 +/- 14 years, 80% men, with drug-resistant persistent AF were implanted with the Jewel AF atrial defibrillator. All patients performed self-administered cardioversion for AF recurrences. Over a 2 year follow-up, 238 patient-activated cardioversions were performed in 14 patients. Sinus rhythm was restored on every occasion with 96% of episodes terminating with a single shock. The median time from AF onset to patient awareness of symptoms was 2.5 hours. The median time from onset of symptoms to cardioversion was 3.5 hours. Comparison of the first and second six month period following implant showed a nonsignificant increase in mean total AF duration (75.7 +/- 107.8 hours vs 146.6 +/- 194.1 hours, P = 0.28). Two patients (13%) had a decreasing frequency of AF recurrences. The majority continued to have regular recurrences of AF. The atrial defibrillator is an extremely effective method of restoring sinus rhythm in patients with persistent AF. Regular early use of the atrial defibrillator, increased the duration of sinus rhythm in a minority of patients during long-term follow-up. Most patients had regular recurrences of AF requiring patient-activated cardioversion.

Background: A circadian variation exists for ventricular defibrillation thresholds (DFTs) with a morning peak and a corresponding decrease in therapy success rates from implantable cardioverter defibrillators. Such a variation in atrial DFTs may have implications for the timing of internal cardioversion of atrial arrhythmias. The aim of this study was therefore to determine the circadian variation of atrial DFTs in patents with recurrent atrial fibrillation (AF)., Methods and Results: Data were collected as part of the worldwide Jewel AF-only study. Patients had recurrent persistent AF and no history of ventricular arrhythmias. The atrial DFT was assessed at device implantation using a step-up protocol and was recorded for 100 patients (age 63.0 +/- 11.7, 74% male, ejection fraction 49.6 +/- 17.8%, left atrial diameter 46 +/- 9 mm). The mean atrial DFT was 6.3 +/- 4.3 J. For the most commonly tested lead configuration (right atrium to coronary sinus in 56 patients), the atrial DFT for patients implanted in the morning (3.3 +/- 1.5 J) was significantly lower than for both the DFT measured in the afternoon (5.8 +/- 3.4 J, p < 0.01) and the DFT measured in the evening (7.4 +/- 5.9 J, p < 0.01)., Conclusion: There may be a significant variation in measured atrial DFT for the right atrium to coronary sinus configuration, with a nadir in the morning. This is the converse to measurements of ventricular DFTs suggesting different regulatory electrophysiological mechanisms. Further investigation of this possible variation is warranted.

Atrial fibrillation is understood to be a re-entrant arrhythmia and for many years electrophysiologists have attempted to pace-terminate the rhythm. Several studies have demonstrated that an excitable gap is present during atrial fibrillation and that the capture of small amounts of atrial tissue is possible. Early attempts to terminate atrial fibrillation however were unsuccessful. The rapid development of pacemaker and defibrillator technology has provided an exciting new direction for the treatment of recurrent symptomatic atrial fibrillation. Results from studies of the effectiveness of atrial anti-tachycardia pacing algorithms have suggested that 50% of atrial arrhythmias (including atrial fibrillation) can be pace-terminated. These findings conflict with data from the electrophysiology laboratory where atrial fibrillation has yet to be convincingly terminated. In this review, the current literature is discussed and possible reasons for this discrepancy are proposed.

Background: The circadian onset patterns and cycle lengths of atrial tachyarrhythmias (AT) were determined in a group of patients with persistent atrial fibrillation., Methods: Fifteen patients, mean age 63 +/- 14 years and 80% male, were implanted with the Jewel AF atrial defibrillator (Medtronic, Minneapolis, Minn) for persistent atrial fibrillation only. Onset times of AT and median onset atrial cycle lengths were determined from device memory., Results: Over a follow-up period of 23.3 +/- 7 months, 227 episodes of persistent AT were treated by patient-activated atrial defibrillation. The peak onset of persistent AT was nocturnal, with 74% of episodes initiating between 8 pm and 8 am. Eighty-seven percent of the patients experienced an additional 403 paroxysmal AT episodes. These episodes showed a "double-peaked" pattern with the least number of episodes occurring between midnight and 8 am. The mean onset atrial cycle length of persistent AT was significantly shorter than the paroxysmal AT episodes (200 +/- 37 ms vs 240 +/- 39 ms, P <.005). The atrial cycle lengths at arrhythmia onset of both paroxysmal and persistent AT episodes also demonstrated circadian variation., Conclusion: There is a circadian distribution of onsets for persistent AT with predominance at night. Patients with persistent AF have >1 type of atrial arrhythmia with differences in the onset patterns and atrial cycle lengths, suggesting different triggers and onset mechanisms.

Unlabelled: Atrial Defibrillator., Introduction: The atrial defibrillator empowers patients to cardiovert themselves from atrial arrhythmias at a time that is socially and physically acceptable, thereby preventing hospitalization. The long-term psychosocial effects of repeated use of the patient-activated atrial defibrillator at home are unknown., Methods and Results: Eighteen patients underwent placement of the Jewel AF atrial defibrillator for persistent atrial fibrillation only. All patients performed manually activated cardioversions at home under self-administered sedation. Automatic shock therapies were disabled. Hospital Anxiety and Depression Scale and Multidimensional Health Locus of Control questionnaires were obtained before implant. All patients completed questionnaires 1 year after device implant and at long-term follow-up. The spouse or partner of each patient was interviewed to identify positive and negative aspects of manual cardioversion at home. The baseline patient scores for both anxiety (5.7 +/- 2.7) and depression (3.4 +/- 2.3) fell within the predefined range of normality. At 1 year, there was no significant change in anxiety (4.9 +/- 3.7, P = 0.39) or depression (2.4 +/- 1.8, P = 0.06). At long-term follow-up (mean 28 months), a total of 377 patient-activated cardioversions were performed out of hospital (median 15 per patient). Scores for anxiety (6.0 +/- 4.0, P = 0.70) and depression (3.2 +/- 2.5, P = 0.68) remained unchanged., Conclusion: During long-term follow-up, patient-activated cardioversion using the atrial defibrillator was not associated with increased anxiety or depression. The procedure was well tolerated by patients and their partners, offering an acceptable treatment option for patients with recurrent persistent atrial fibrillation.

Background: The patient-activated atrial defibrillator allows patients to cardiovert themselves from atrial fibrillation soon after the onset of symptoms. The long-term effects of early cardioversion from persistent atrial fibrillation on left ventricular performance and left atrial size are unknown., Methods: Eighteen patients, mean age 63.4, 83% male, had the Jewel((R)) AF atrial defibrillator implanted for persistent atrial fibrillation only. Transthoracic echocardiography was performed 3-monthly following implant. Parasternal long axis measurements were taken using conventional M-mode techniques., Results: Over follow-up of 28.0+/-9 months, 377 episodes of persistent atrial fibrillation were terminated by patient-activated cardioversion (median 15 per patient). Echocardiographic measurements at implant were; left atrium 44+/-6 mm, left ventricular end-diastolic diameter 49+/-7 mm, left ventricular end-systolic diameter 34+/-7 mm, fractional shortening 33+/-10% and ejection fraction 65+/-17%. After 1 year there had been a significant decrease in mean left atrial size to 41+/-6 mm (P=0.02) and an increase in mean ejection fraction to 73+/-8% (P=0.04). At long-term follow-up however, all parameters reverted to pre-implant levels. Baseline echocardiographic variables did not predict which patients would demonstrate serial increases in sinus rhythm duration between shocks during long-term follow-up. Patients on antiarrhythmic drug therapy however were more likely to demonstrate "sinus rhythm begetting sinus rhythm"., Conclusions: Use of the atrial defibrillator for spontaneous persistent atrial fibrillation is associated with a medium-term (1 year) reduction in left atrial size and an increase in ejection fraction. These changes were not maintained in the long-term. Synergistic therapy with antiarrhythmic drugs may prolong periods of sinus rhythm between arrhythmia recurrences.

Atrial fibrillation is the most common clinical arrhythmia and with an aging population it is becoming an increasing cause of morbidity and hospitalisation. Antiarrhythmic drug therapy unfortunately remains only moderately effective at preventing recurrences of arrhythmia. Attention has now therefore focussed on the development of non-drug techniques to prevent or treat atrial fibrillation in highly symptomatic patients. There are a number of theoretical ways that pacing the atrium may prevent arrhythmias and pacemakers are under investigation for the prevention and termination of atrial arrhythmias with additional tailored, programmable algorithms. The increased memory capacity and diagnostic capabilities of these devices allows the true efficacy of pacemaker interventions to be determined. Early results from studies suggest that the implantation of such pacemakers can reduce atrial fibrillation burden and thereby obviate the need for more invasive procedures such as atrioventricular nodal ablation. The improved diagnostics also provides enhanced information about the onset of atrial arrhythmias and suggests that atrial fibrillation may have periods of high organisation and a window for pace termination. The atrial defibrillator is a useful, but expensive, therapeutic option in patients with recurrent symptomatic persistent atrial fibrillation and the current generation of devices allow patients to activate the device at home using a hand-held activator. This reduces the need for hospitalisation and empowers the patient to 'take charge' of their condition.

Abstract: Atrial fibrillation (AF) is the commonest clinical arrhythmia and one that will be faced frequently by doctors throughout their medical career. AF is a significant cause of symptoms, hospitalisation, morbidity and mortality. With an increasing and ageing population, the number of patients being treated with AF continues to rise with enormous demands on healthcare funds and resources. In spite of tremendous advances in cardiovascular medicine over the last century, antiarrhythmic therapy remains only moderately effective at preventing AF, it needs to be patient-tailored and it can be associated with significant side-effects. Additionally, oral anti-thrombotic therapy has barely altered in the last fifty years. New electrophysiological techniques are now allowing patients to be offered ablation therapy to reduce AF onsets with promising results. With the likelihood of new anti-arrhythmics and anti-thrombotic medications on the horizon, perhaps we can be optimistic about the future for the patient with this stubborn condition. This article discusses current aspects of AF diagnosis, clinical management and therapies and examines the role of drug therapy, stroke risk reduction and the use of ablation. [Copyright &y& Elsevier]

With an ageing population, atrial fibrillation has become an increasing cause of hospital admission and morbidity. Pacemaker implantation may prevent atrial tachyarrhythmias by preventing bradycardia and pauses. Implantable devices are now available with specific atrial pacing algorithms designed to prevent atrial arrhythmias. These algorithms work by increasing the atrial pacing rate to achieve continuous overdrive pacing or by responding to triggers such as premature atrial complexes. This article examines how the algorithms work by describing the functions of one of the new generation of pacemakers in detail. Early studies have indicated that the use of preventative pacing can reduce atrial arrhythmia burden and symptomatic atrial fibrillation in selected patients. There are clearly some patients who benefit from implantation of these devices but what remains unclear is how to identify this patient group. [ABSTRACT FROM PUBLISHER]

The author asserts that restoring sinus rhythm is more important than a rate control strategy in patients with atrial fibrillation. He cites randomised trials which showed rhythm control has no clear mortality benefit over rate control in patients with asymptomatic atrial fibrillation during two to three years of follow-up. Other studies that point towards the benefits of restoring sinus rhythm are cited. According to the author, the restoration of sinus rhythm has many advantages including making the patient feel better, reducing the risk of emergency hospital admission and stroke, and improving exercise capacity.

Presents a letter to the editor in the August 2003 issue of the 'Journal of Cardiovascular Electrophysiology,' noting the additional data on the effectiveness of a coronary sinus electrode in reducing the atrial defibrillation threshold. Observation of high atria defibrillation threshold measurements observed in patients with persistent atrial fibrillation.