Frequent Atrial Premature Beats Predict Paroxysmal Atrial Fibrillation in Stroke Patients

Reprint of: Scientific statement from the French neurovascular and cardiac societies for improved detection of atrial fibrillation after ischaemic stroke and transient ischaemic attack

Atrial fibrillation (AF) is the primary cause of ischaemic stroke and transient ischaemic attack (TIA). AF is associated with a high risk of recurrence, which can be reduced using optimal prevention strategies, mainly anticoagulant therapy. The availability of effective prophylaxis justifies the need for a significant, coordinated and thorough transdisciplinary effort to screen for AF associated with stroke. A recent French national survey, initiated and supported by the Société française neurovasculaire (SFNV) and the Société française de cardiologie (SFC), revealed many shortcomings, such as the absence or inadequacy of telemetry equipment in more than half of stroke units, insufficient and highly variable access to monitoring tools, delays in performing screening tests, heterogeneous access to advanced or connected ambulatory monitoring techniques, and a lack of dedicated human resources. The present scientific document has been prepared on the initiative of the SFNV and the SFC with the aim of helping to address the current shortcomings and gaps, to promote efficient and cost-effective AF detection, and to improve and, where possible, homogenize the quality of practice in AF screening among stroke units and outpatient post-stroke care networks. The working group, composed of cardiologists and vascular neurologists who are experts in the field and are nominated by their peers, reviewed the literature to propose statements, which were discussed in successive cycles, and maintained, either by consensus or by vote, as appropriate. The text was then submitted to the SFNV and SFC board members for review. This scientific statement document argues for the widespread development of patient pathways to enable the most efficient AF screening after stroke. This assessment should be carried out by a multidisciplinary team, including expert cardiologists and vascular neurologists.

Scientific statement from the French neurovascular and cardiac societies for improved detection of atrial fibrillation after ischaemic stroke and transient ischaemic attack

Atrial fibrillation (AF) is the primary cause of ischaemic stroke and transient ischaemic attack (TIA). AF is associated with a high risk of recurrence, which can be reduced using optimal prevention strategies, mainly anticoagulant therapy. The availability of effective prophylaxis justifies the need for a significant, coordinated and thorough transdisciplinary effort to screen for AF associated with stroke. A recent French national survey, initiated and supported by the Société française neurovasculaire (SFNV) and the Société française de cardiologie (SFC), revealed many shortcomings, such as the absence or inadequacy of telemetry equipment in more than half of stroke units, insufficient and highly variable access to monitoring tools, delays in performing screening tests, heterogeneous access to advanced or connected ambulatory monitoring techniques, and a lack of dedicated human resources. The present scientific document has been prepared on the initiative of the SFNV and the SFC with the aim of helping to address the current shortcomings and gaps, to promote efficient and cost-effective AF detection, and to improve and, where possible, homogenize the quality of practice in AF screening among stroke units and outpatient post-stroke care networks. The working group, composed of cardiologists and vascular neurologists who are experts in the field and are nominated by their peers, reviewed the literature to propose statements, which were discussed in successive cycles, and maintained, either by consensus or by vote, as appropriate. The text was then submitted to the SFNV and SFC board members for review. This scientific statement document argues for the widespread development of patient pathways to enable the most efficient AF screening after stroke. This assessment should be carried out by a multidisciplinary team, including expert cardiologists and vascular neurologists.

Yield of Cardiac Investigations in Patients Presenting with Acute Ischaemic Stroke: A single tertiary centre experience

Objectives

Strokes are a major cause of morbidity and mortality. This study aimed to evaluate the effectiveness of routine cardiac investigations in identifying a cardioembolic aetiology for ischaemic strokes.

Methods

This retrospective study involved patients who presented with a stroke to the Sultan Qaboos University Hospital, Muscat, Oman, between January and December 2019.

Results

A total of 183 patients (mean age = 66.2 ± 13.5 years), the majority of which were male (n = 109, 59.6%), were included. The common risk factors included hypertension (74.9%), diabetes (61.7%) and hyperlipidaemia (54.6%). The middle cerebral artery was the most common artery affected, in 44 patients (24.0%). On admission, 14 (7.6%) patients were in atrial fibrillation (AF), while the rest were in sinus rhythm. The 24-hour electrocardiogram (ECG) Holter monitoring revealed no abnormalities in 135 patients. AF was observed in 15 (8.1%) patients (inclusive of the 14 who had AF on resting ECG). Furthermore, 32 (17.4%) patients had evidence of non-sustained atrial arrhythmia, and nine (4.9%) had non-sustained ventricular tachycardia. Frequent supraventricular ectopics (>30/hour) was noted on 30 patients (16.3%), while five (2.7%) patients had a high ventricular ectopic burden (>10% burden). No significant abnormalities were noted in the echocardiograms of the patients; however, 10 out of 132 (7.5%) patients presented a positive bubble echo. Enlarged left atria were found in 24 (13.1%) patients.

Conclusion

The overall diagnostic yield of the abnormalities from routine cardiac testing for patients with stroke appears to be low. Targeted screening of patients with cryptogenic stroke, as suggested by newer guidelines, is recommended.

Value of baseline characteristics in the risk prediction of atrial fibrillation

Introduction

Atrial fibrillation (AF) is prone to heart failure and stroke. Early management can effectively reduce the stroke rate and mortality. Current clinical guidelines screen high-risk individuals based solely on age, while this study aims to explore the possibility of other AF risk predictors.

Methods

A total of 18,738 elderly people (aged over 60 years old) in Chinese communities were enrolled in this study. The baseline characteristics were mainly based on the diagnosis results of electrocardiogram (ECG) machine during follow up, accompanied by some auxiliary physical examination basic data. After the analysis of both independent and combined baseline characteristics, AF risk predictors were obtained and prioritized according to the results. Independent characteristics were studied from three aspects: Chi-square test, Mann-Whitney U test and Cox univariate regression analysis. Combined characteristics were studied from two aspects: machine learning models and Cox multivariate regression analysis, and the former was combined with recursive feature elimination method and voting decision.

Results

The resulted optimal combination of risk predictors included age, atrial premature beats, atrial flutter, left ventricular hypertrophy, hypertension and heart disease.

Conclusion

Patients diagnosed by short-time ECG machines with the occurrence of the above events had a higher probability of AF episodes, who are suggested to be included in the focus of long-term ECG monitoring or increased screening density. The incidence of risk predictors in different age ranges of AF patients suggests differences in age-specific patient management. This can help improve the detection rate of AF, standardize the management of patients, and slow down the progression of AF.

Excessive Supraventricular Ectopic Activity and the Risk of Atrial Fibrillation and Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Excessive supraventricular ectopic activity (ESVEA) is correlated with the development of atrial fibrillation (AF) and is frequently observed in ischemic stroke patients. This meta-analysis aims to summarize the evidence on the association between ESVEA and the risk of AF and stroke.

METHODS

PubMed and Embase databases were systematically searched to identify all publications providing relevant data from inception to 23 August 2022. Hazard ratio (HR) and 95% confidence interval (CI) were pooled using fixed-effect or random-effect models.

RESULTS

We included 23,272 participants from 20 studies. Pooled results showed that ESVEA was associated with an increased risk of AF in the general population (HR: 2.57; 95% CI 2.16-3.05), increased risk of AF in ischemic stroke patients (HR: 2.91; 95% CI 1.80-4.69), new-onset ischemic stroke (HR: 1.91; 95% CI 1.30-2.79), and all-cause mortality (HR: 1.41; 95% CI 1.24-1.59). Pooled analysis indicated that ESVEA was not associated with recurrent ischemic stroke/transient ischemic attack (TIA) (HR: 1.24; 95% CI 0.91-1.67).

CONCLUSIONS

ESVEA is associated with AF, new-onset ischemic stroke, and all-cause mortality.

Electrocardiographic Risk Factors for a Common Cardiac Condition

This case report describes a patient in their 60s with a history of several months of recurrent dizziness and occasional palpitation who presented to the emergency department after an episode of syncope.

Prediction of atrial fibrillation using a home blood pressure monitor with a high-resolution system

Objective

The usefulness of screening for atrial fibrillation (AF) using several home blood pressure (BP) monitors has been reported. We evaluated the accuracy of a high-resolution system (HiRS) for AF prediction and its usefulness when installed in home BP monitors.

Methods

In patients with paroxysmal, persistent or permanent AF, ECG recording and BP measurements were performed simultaneously. The relationship between ECG rhythm diagnosis and pulse irregularity recognition, using a home BP monitor with HiRS, was investigated. The severity of a pulse disturbance during BP measurement was displayed as an irregular pulse rhythm symbol (IPRS) in three instances. The IPRS was not displayed if the pulse was regular, turned on if there was a weak variation in the pulse, and blinked if there was a strong variation in the pulse.

Results

One hundred and seven patients (44 paroxysmal AF, 63 persistent or permanent AF) were enrolled, and a total of 333 recordings were analysed. The rhythms recorded by each ECG were 73 sinus regular rhythms, 35 extrasystoles, 222 AFs and 3 atrial flutters. Sensitivity and specificity for the prediction of any arrhythmia by the IPRS display of the BP monitor were 95.8% (95% CI 92.6% to 97.6%) and 96.8% (95% CI 92.6% to 100%), respectively. In addition, sensitivity and specificity for the prediction of AF were 100% (95% CI 97.5% to 100%) and 74.8% (95% CI 65.6% to 82.5%), respectively. Sensitivity and specificity for the prediction of AF by the IPRS blinking display were 88.3% (95% CI 83.3% to 92.2%) and 94.6% (95% CI 88.6% to 98.0%%), respectively. IPRS exhibited lighting or blinking during AF occurrence; however, during sinus rhythm, IPRS was not displayed in 72 out of 73 recordings.

Conclusion

The IPRS device predicted AF with precision and may be particularly useful for predicting an arrhythmia attack in patients with paroxysmal AF.

ESC Working Group on e-Cardiology Position Paper: accuracy and reliability of electrocardiogram monitoring in the detection of atrial fibrillation in cryptogenic stroke patients : In collaboration with the Council on Stroke, the European Heart Rhythm Association, and the Digital Health Committee

The role of subclinical atrial fibrillation as a cause of cryptogenic stroke is unambiguously established. Long-term electrocardiogram (ECG) monitoring remains the sole method for determining its presence following a negative initial workup. This position paper of the European Society of Cardiology Working Group on e-Cardiology first presents the definition, epidemiology, and clinical impact of cryptogenic ischaemic stroke, as well as its aetiopathogenic association with occult atrial fibrillation. Then, classification methods for ischaemic stroke will be discussed, along with their value in providing meaningful guidance for further diagnostic efforts, given disappointing findings of studies based on the embolic stroke of unknown significance construct. Patient selection criteria for long-term ECG monitoring, crucial for determining pre-test probability of subclinical atrial fibrillation, will also be discussed. Subsequently, the two major classes of long-term ECG monitoring tools (non-invasive and invasive) will be presented, with a discussion of each method's pitfalls and related algorithms to improve diagnostic yield and accuracy. Although novel mobile health (mHealth) devices, including smartphones and smartwatches, have dramatically increased atrial fibrillation detection post ischaemic stroke, the latest evidence appears to favour implantable cardiac monitors as the modality of choice; however, the answer to whether they should constitute the initial diagnostic choice for all cryptogenic stroke patients remains elusive. Finally, institutional and organizational issues, such as reimbursement, responsibility for patient management, data ownership, and handling will be briefly touched upon, despite the fact that guidance remains scarce and widespread clinical application and experience are the most likely sources for definite answers.

[Remote monitoring of implantable monitors : Towards coverage ? Evaluation of the procedure by the French National Authority for Health]

Implantable cardiac monitors are recommended and reimbursed in two specific cases: the etiological diagnosis of unexplained recurrent syncope and the etiological diagnosis of a cryptogenic ischemic stroke. According to the French National Authority for Health (HAS), remote monitoring "leads to early diagnosis and therapeutic care". However, remote tracking of these devices for diagnostic purposes is not included in the ETAPES program, which will end soon. This article presents a summary of the evaluation by HAS of the remote monitoring of implantable cardiac monitors. It also addresses the question of its reimbursement, as for therapeutic implantable devices.

Embolic Stroke of Undetermined Source: Approaches in Risk Stratification for Cardioembolism

Ischemic stroke is a leading cause of morbidity and mortality worldwide. Embolic stroke of undetermined source has been recently proposed to categorize nonlacunar ischemic strokes without confirmed etiology after adequate investigation with a likely embolic stroke mechanism. A strategy of empirical anticoagulation for embolic stroke of undetermined source patients is attractive but may only be beneficial in a select subset of patients. Strategies which would help identify the subset of embolic stroke of undetermined source patients most likely to have cardioembolic origin of stroke, and hence benefit from anticoagulation, are needed. This article will review current evidence which may be useful in the development of a risk stratification approach based on arrhythmia monitoring, cardiac imaging, and clinical risk stratification. This approach may be beneficial in clinical practice in improving patient outcomes and reducing stroke recurrence in this population; however, further work is required with active trials underway.

Revisit to the Prognostic Value of Premature Atrial Contraction Burden in 24-h Holter Electrocardiography for Predicting Undiagnosed Atrial Fibrillation - A Propensity Score-Matched Study

BACKGROUND

The optimum cut-off value of premature atrial contraction (PAC) burden (CV-PACb) in 24-h Holter electrocardiography (24-h ECG) for predicting atrial fibrillation (AF) is debatable, with few validation data.

METHODS AND RESULTS

We retrospectively analyzed 61 patients already diagnosed with AF (AD-AF) and 147 patients never diagnosed with AF (ND-AF), aged ≥50 years, free of heart disease, and who had undergone 24-h ECG and transthoracic echocardiography (TTE). Receiver operating characteristic analysis demonstrated that 0.4% was the optimal CV-PACb differentiating AD-AF from ND-AF, with 69% sensitivity and 72% specificity (area under the curve [AUC] 0.72; 95% confidence interval [CI] 0.65-0.79); however, the left atrial volume index was not significant (AUC 0.60; 95% CI 0.51-0.68). To verify the CV-PACb, new propensity-matched cohorts (i.e., subjects with a PAC burden ≥0.4% and <0.4%; n=69 in each group) were compared based on new detection of AF at a median follow-up of 50 months (interquartile range 12-60 months) Multivariable Cox regression analysis revealed that among 24-h ECG and TTE findings, only PAC burden ≥0.4% was independently associated with incident AF (hazard ratio 5.28; 95% CI 1.28-26.11; P=0.023).

CONCLUSIONS

A high PAC burden (≥0.4%) in 24-h ECG was a reliable indicator to identify undiagnosed AF, whereas TTE parameters did not show any predictive value.

Prevalence and predictors of subclinical atrial fibrillation in hospitalized older adults

Subclinical atrial fibrillation (SCAF) is associated with an increased risk of clinical AF, major cardiovascular events and death. Short-term evidence on SCAF in older populations is scarce, especially in the hospital setting. We performed a cross-sectional study on 60 multimorbid older consecutive patients (aged 80+) admitted to an Internal Medicine and Geriatrics Unit for acute medical diseases with no history of AF, in order to investigate prevalence and predictors of SCAF. Portable ECG monitoring was placed on admission and ECG recording lasted for 5 days. Mean age: 85.7±4.9 years. Female prevalence: 58.3%. High burden of comorbidities: 87.9%. All enrolled patients had CHA₂DS₂-VASc score ≥3. SCAF was detected in 16 patients (26.7%) and 11 patients (18.4%) had at least a SCAF episode lasting 6 minutes or longer. No clinical, laboratory and echocardiographic parameters predicted SCAF. Patients with ≥2004 supraventricular ectopic beats/24h (SVEBs/24h) had a 6-fold higher prevalence of SCAF than patients with <411 SVEBs/24h (p=0.038). Time to first SCAF episode was within 3 days of ECG recording in all enrolled patients. SCAF is highly prevalent in older adults hospitalized for acute diseases. This finding may affect clinical management and prognosis. Our study could foster larger multicenter studies in similar settings.

Premature atrial complexes can predict atrial fibrillation in ischemic stroke patients: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Several studies have explored premature atrial complexes (PACs) as high-risk factors for atrial fibrillation (AF) in ischemic stroke patients; however, the results were controversial. The aim of this systematic review and meta-analysis was to examine whether PACs can predict AF in ischemic stroke patients.

METHODS

We comprehensively searched the published literature in PubMed, Embase, and Wiley-Cochrane library databases from inception through August 18, 2020. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were analyzed by the fixed-effect model or the random-effect model based on heterogeneity.

RESULTS

We identified 12 eligible studies including 2340 stroke patients with a mean age of 65.9 years. PACs were highly associated with AF occurrence in stroke (pooled OR: 4.16, 95% CI: 3.06-5.65) and cryptogenic stroke patients (pooled OR: 3.72, 95% CI: 2.66-5.20). Subgroup analysis showed PAC presence and frequent PACs were correlated with stroke in AF patients (pooled OR: 3.72, 95% CI: 1.65-8.36 and pooled OR: 5.12, 95% CI: 3.12-8.41, respectively). Frequent PACs were identified as the risks for asymptomatic AF (OR: 6.18, 95% CI: 3.23-11.83) and future AF occurrence (OR: 3.71, 95% CI: 2.62-5.26) in stroke patients. The definition of frequent PACs was inconsistent, and was >70 beats/24 h based on Holter monitoring.

CONCLUSIONS

PACs confer high risks for asymptomatic AF and future AF occurrence in stroke patients.

Atrial Fibrillation After Ischemic Stroke Detected by Chest Strap-Style 7-Day Holter Monitoring and the Risk Predictors: EDUCATE-ESUS

AIM

This study aimed to investigate the diagnostic yield of 7-day Holter monitoring for detecting covert atrial fibrillation (AF) in patients with recent embolic stroke of undetermined source (ESUS) and to identify the pre-entry screening biomarkers that had significant associations with later detection of AF (clinicaltrials.gov. NCT02801708).

METHODS

A total of 206 patients who have recent ESUS without previously documented AF underwent Holter electrocardiography using a chest strap-style monitor. External validation of biomarkers predictive of AF was performed using 83 patients with ESUS who were implanted with insertable cardiac monitors.

RESULTS

The 7-day Holter monitoring started at a median of 13 days after the onset of stroke. AF was detected in 14 patients, and three of these showed a single AF episode lasting ＜2 min. The median time delay to the first documented AF was 50 h. Each of serum brain natriuretic peptide ≥ 66.0 pg/mL (adjusted odds ratio 5.23), atrial premature contractions (APCs) ≥ 345 beats (3.80), and APC short runs ≥ 13 (5.74) on 24-h Holter prior to the 7-day Holter showed a significant association with detection of AF, independent of age and physiological findings in this derivation cohort, and all of these showed a significant association in the validation cohort (adjusted odds ratio 6.59, 7.87, and 6.16, respectively).

CONCLUSIONS

In recent ESUS patients, the detection rate of AF using the 7-day Holter monitoring was 6.8% (95% CI 4.1%-11.1%). Brain natriuretic peptide, APC count, and APC short runs in the standard clinical workup seemed to be predictors of covert AF.

Pulmonary vein volume and myocardial sleeve extension estimated by 3D computed tomography and voltage mapping predict arrhythmogenic triggers of paroxysmal atrial fibrillation

PURPOSE

Relationship between pulmonary vein (PV) anatomy and the pathophysiology of paroxysmal atrial fibrillation (PAF) remains incompletely studied. The aim of this study was to determine whether PV anatomy predicts arrhythmogenic PVs.

METHODS

Twenty-six consecutive PAF patients with spontaneous PAF or consistently frequent ectopic beats during electrophysiological study were enrolled. Computed tomography (CT) images for PVs were reconstructed into 3D images. The PV diameter and volume were measured based on the 3D images. The PV myocardial sleeve area was measured based on the 3D voltage mapping results. The PV myocardial sleeve area index was calculated by dividing the sleeve area of each PV by the average sleeve area of all PVs in each patient.

RESULTS

The diameter and volume of the arrhythmogenic PVs were larger than those of the non-arrhythmogenic PVs (21.08 ± 4.57 mm vs. 16.47 ± 3.31 mm, P < 0.001 and 7.70 ± 3.28 cm³ vs. 4.09 ± 1.99 cm³, P < 0.001, respectively). The myocardial sleeve area and sleeve area index of the arrhythmogenic PVs were also larger than those of the non-arrhythmogenic PVs (8.62 ± 5.33 cm² vs. 4.77 ± 3.84 cm², P < 0.001 and 1.59 ± 0.35 vs. 0.81 ± 0.38, P < 0.001, respectively). Multivariate analysis showed the PV myocardial sleeve area index was the independent predictor for arrhythmogenic PVs (P < 0.001).

CONCLUSIONS

PV size plays an important role in triggering PAF. A large myocardial sleeve extension is a powerful and independent predictor for arrhythmogenic PV, which may be useful anatomical markers to facilitate PAF ablation.

Premature Atrial Contractions and Their Association with Stroke Features and Outcome

BACKGROUND

Frequent premature atrial contractions (PACs) are associated with atrial fibrillation, stroke, and mortality. However, the cut-off value for PAC counts that could identify patients with different stroke features is unclear, and the association of PACs to outcome is not determined.

METHODS

The study retrospectively included patients with acute ischemic stroke who had underwent both a 24 h Holter recording and a brain MRI in Taipei Veterans General Hospital from January 2015 to May 2016. Patients were categorized into four groups according to their PAC frequencies on 24 h Holter recording. We compared the clinical severity, neuroimage features, stroke subtypes, and functional outcome among the four groups of patients.

RESULTS

Among the 278 patients, the lower, middle, and upper quartiles of the PAC counts were 23, 74, and 459.5, respectively. In contrast to the 1^st quartile of patients, the 3^rd (PAC 75-459/24 h) and the 4^th (PAC ≥460/24 h) quartiles of patients had higher NIH Stroke Scale (NIHSS) at admission (p = 0.014 and p = 0.002, respectively). The frequencies of cryptogenic stroke were not different among the 4 quartiles of the patients, but cryptogenic stroke patients with ≥ 75PACs/24hours had higher stroke severity compared to those with PACs < 75counts/24 h (NIHSS 9.1 vs. 5.2, p = 0.043). There was an increased trend in infarcts of multiple vascular territories and in mortality at 1 year among the four groups of patients with increased PAC frequency (p = 0.045 and p = 0.002, respectively). The 4^th PAC quartile was associated with poor functional outcome (modified Rankin Scale ≥ 4) at 3 months in univariate analysis (OR: 5.66, CI: 2.69-11.91, p < 0.001), but was not an independent predictor after controlling for initial stroke severity.

CONCLUSIONS

PACs ≥ 75 counts/24 h was associated with higher clinical severity in patients with acute ischemic stroke.

The prevalence of atrial premature complexes in healthy Doberman Pinschers and their role in the diagnosis of occult dilated cardiomyopathy

The importance of atrial premature complexes (APCs) as a possible marker of occult dilated cardiomyopathy (DCM) in Doberman Pinschers (DP) is unknown. The aim of this study was to identify APC in healthy DP and to investigate their role as early markers of occult DCM. Holter-ECG results from 561 examinations of 153 DP at different time points were retrospectively evaluated, with special emphasis on APCs. Holter results from 110 healthy control DPs were compared to the last normal Holter and echocardiographic examinations in 43 DP that subsequently developed DCM within 15 months (DCM group), and to the first examination in the DCM group that contained ventricular premature complexes (VPC). There were no significant differences in the number of APCs or the coupling interval between the control group and the last normal examination in the DCM group (P > 0.05). The number of APCs increased slightly at the first abnormal examination in the DCM group. Healthy male DP had more APCs than females (P = 0.009) and older dogs had APCs more frequently than younger dogs (P < 0.001). About 85% of healthy DP with at least one APC/24 h had <20 APCs/24 h. Extracardiac diseases, especially gastrointestinal diseases influenced the occurrence of APCs (P = 0.037 and P = 0.006, respectively). APCs were present without obvious cardiac disease and were not a marker for the development of DCM, as they were not identified until after VPCs were present.

Temporal patterns of premature atrial complexes predict atrial fibrillation occurrence in bradycardia patients continuously monitored through pacemaker diagnostics

The frequency of premature atrial complexes (PACs) has been related with atrial fibrillation (AF) occurrence and adverse prognosis. Research objective was to evaluate whether temporal patterns of PACs are directly associated with AF onset in pacemaker patients with continuous monitoring of the atrial rhythm. Overall, 193 pacemaker patients (49% female, 72 ± 9 years old), enrolled in a national registry, were analyzed. Frequency of daily PACs was measured in a 14-day initial observation period, during which patients were in sinus rhythm. In the following period, temporal occurrence and frequency of daily PACs and eventual onset of AF were derived by pacemaker diagnostics. In the run-in period, median PACs frequency was 614 PACs/day (interquartile range 70-3056). Subsequently, in a median follow-up of 6 months, AF occurred in 109 patients, in particular in 37/96 (38.5%) patients with a PAC rate < 614 PACs/day and in 72/97 (74.2%) patients with PAC rate ≥ 614 PACs/day (p < 0.001). In patients with AF occurrence, the number of daily PACs, normalized by dividing for the average of PACs in ten preceding days, progressively increased in the 5 days preceding AF. Cox model predictive analysis showed that the risk of AF was significantly higher in patients with a relative increase of the daily PACs higher than 30% compared with PACs average number in ten preceding days [hazard ratio (95% confidence interval) 3.67 (2.40-5.59), p < 0.001]. PACs frequency increases in the 5 days preceding AF onset. A relative increase of the daily PACs is significantly associated with the risk of AF occurrence.

Excessive Supraventricular Ectopic Activity and Adverse Cardiovascular Outcomes: a Systematic Review and Meta-analysis

PURPOSE OF REVIEW

Excessive supraventricular ectopic activity (ESVEA), in the form of frequent premature atrial contractions (PACs) and runs of PACs, is commonly observed in clinical practice and is frequently considered to be benign. Yet, recent studies have demonstrated a link between ESVEA and adverse cardiovascular outcomes. The aim of this meta-analysis was to examine the association between ESVEA and the risk of atrial fibrillation (AF), stroke, and mortality.

RECENT FINDINGS

A systematic search was performed in PubMed, EMBASE, and the Cochrane Library up to December 2017 to identify studies assessing adverse cardiovascular outcomes in patients with ESVEA, recorded on ambulatory electrocardiography. ESVEA was defined as a burden of PACs > 30 PACs/h or any runs of ≥20 PACs. The risk estimates for EVSEA and each clinical endpoint were pooled and analyzed separately.

RESULTS

Five studies comprising 7545 participants were included in this meta-analysis. The pooled analysis showed that ESVEA doubled the risk of AF (HR 2.19, 95% CI 1.70-2.82). ESVEA was also associated with a higher incidence of stroke (HR 2.23, 95% CI 1.24-4.02). Finally, ESVEA was associated with higher all-cause mortality (HR 1.61, 95% CI 1.25-2.07). Our meta-analysis found that ESVEA is closely associated with AF, stroke, and all-cause mortality. Further studies are required to examine the implication of therapeutic strategies in patients with ESVEA, in order to prevent potential subsequent adverse cardiovascular outcomes.

Identification of patients with embolic stroke of undetermined source and low risk of new incident atrial fibrillation: The AF-ESUS score

Background and aims

Only a minority of patients with Embolic Stroke of Undetermined Source (ESUS) receive prolonged cardiac monitoring despite current recommendations. The identification of ESUS patients who have low probability of new diagnosis of atrial fibrillation (AF) could potentially support a strategy of more individualized allocation of available resources and hence, increase their diagnostic yield. We aimed to develop a tool that can identify ESUS patients who have low probability of new incident AF.

Methods

We performed multivariate stepwise regression in a pooled dataset of consecutive ESUS patients from three prospective stroke registries to identify predictors of new incident AF. The coefficient of each independent covariate of the fitted multivariable model was used to generate an integer-based point scoring system.

Results

Among 839 patients (43.1% women, median age 67.0 years) followed-up for a median of 24.3 months (2999 patient-years), 125 (14.9%) had new incident AF. The proposed score assigns 3 points for age ≥ 60 years; 2 points for hypertension; −1 point for left ventricular hypertrophy reported at echocardiography; 2 points for left atrial diameter >40 mm; −3 points for left ventricular ejection fraction <35%; 1 point for the presence of any supraventricular extrasystole recorded during all available 12-lead standard electrocardiograms performed during hospitalization for the ESUS; −2 points for subcortical infarct; −3 points for the presence of non-stenotic carotid plaques. The rate of new incident AF during follow-up was 1.97% among the 42.3% of the cohort who had a score of ≤0, compared to 26.9% in patients with > 0 (relative risk: 13.7, 95%CI: 5.9--31.5). The area under the curve of the score was 84.8% (95%CI: 79.9--86.9%). The sensitivity and negative predictive value of a score of ≤0 for new incident AF during follow-up were 94.9% (95%CI: 89.3--98.1%) and 98.0% (95%CI: 95.8--99.3%), respectively.

Conclusions

The proposed AF-ESUS score has high sensitivity and high negative predictive value to identify ESUS patients who have low probability of new incident AF. Patients with a score of 1 or more may be better candidates for prolonged automated cardiac monitoring.

Clinical trial registration

URL: https://www.clinicaltrials.gov / Unique identifier: NCT02766205.

Application of Dispersion Entropy to Healthy and Pathological Heartbeat ECG Segments

Entropy quantification algorithms are a prominent tool for the quantification of irregularity in biological signal segments towards the characterization of the physiological state of individuals. This paper investigates the potential of Dispersion Entropy (DisEn) as a non-linear method to quantify the uncertainty of ECG signal segments for different types of heartbeats and the stratification of healthy heartbeats for the potential detection of developing pathologies in individuals. Our results indicate that the DisEn algorithm produces distributions with significant differences for the considered types of heartbeats, with higher DisEn values being more prominent in pathological heartbeats and normal heartbeats preceding them. This suggests that, with further research, DisEn algorithms can be integrated with heartbeat detection and classification algorithms for the improvement of medical prognosis through ECG signal processing.

Arrhythmias in Patients on Maintenance Dialysis: A Cross-sectional Study

RATIONALE & OBJECTIVE

Patients with kidney failure treated with maintenance dialysis experience a high rate of mortality, in part due to sudden cardiac death caused by arrhythmias. The prevalence of arrhythmias, including the subset that are clinically significant, is not well known. This study sought to estimate the prevalence of arrhythmias, characterize the pattern of arrhythmic events in relation to dialysis treatments, and identify associated clinical characteristics.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

152 patients with kidney failure treated with maintenance dialysis in Denmark.

EXPOSURES

Dialysis treatment; clinical characteristics; cardiac output and preload defined using echocardiography.

OUTCOMES

Prevalence and pattern of arrhythmias on 48-hour Holter monitoring; odds ratios for arrhythmias.

ANALYTICAL APPROACH

Descriptive analysis of the prevalence of arrhythmias. Pattern of arrhythmias described using a repeated-measures negative binomial regression model. Associations between clinical characteristics and echocardiographic findings with arrhythmias were assessed using logistic regression.

RESULTS

Among the 152 patients studied, 83.6% were treated with in-center dialysis; 10.5%, with home hemodialysis; and 5.9%, with peritoneal dialysis. Premature atrial and ventricular complexes were seen in nearly all patients and 41% had paroxysmal supraventricular tachycardia. Clinically significant arrhythmias included persistent atrial fibrillation observed among 8.6% of patients, paroxysmal atrial fibrillation among 3.9%, nonsustained ventricular tachycardia among 19.7%, bradycardia among 4.6%, advanced second-degree atrioventricular block among 1.3%, and third-degree atrioventricular block among 2.6%. Premature ventricular complexes were more common on dialysis days, while tachyarrhythmias were more often observed during dialysis and in the immediate postdialytic period. Older age (OR per 10 years older, 1.53; 95% CI, 1.15-2.03; P=0.003), elevated preload (OR, 4.02; 95% CI, 1.05-15.35; P=0.04), and lower cardiac output (OR per 1L/min greater, 0.66; 95% CI, 0.44-1.00; P=0.05) were independently associated with clinically significant arrhythmias.

LIMITATIONS

Arrhythmia monitoring limited to 48 hours; small sample size; heterogeneous nature of the population, risk for residual confounding.

CONCLUSIONS

Arrhythmias, including clinically significant abnormal rhythms, were common. Tachyarrhythmias were more frequent during dialysis and the immediate postdialytic period. The relevance of these findings to clinical outcomes requires additional study.

[Contribution of Holter ECG in the etiologic diagnosis of the ischemic stroke in Brazzaville, Congo]

Déterminer la prévalence des troubles rythmiques au cours des infarctus cérébraux et identifier les facteurs prédictifs de la fibrillation atriale (FA) paroxystique. Il s'est agi d'une étude transversale, descriptive et analytique, menée à Brazzaville entre janvier 2012 et décembre 2016. Elle a porté sur une série consécutive de 267 patients victimes d'un accident vasculaire cérébral ischémique transitoire (n = 17) ou constitué (n = 250), documenté par un scanner cérébral. Tous ces patients ont bénéficié d'un enregistrement Holter ECG dès 24h, réalisé dans le cadre de la recherche étiologique. Les principales anomalies rythmiques enregistrées ont été répertoriées et la régression logistique a permis l'identification des facteurs prédictifs de survenue de la FA paroxystique. Il s'agissait de 164 hommes (61,4%) et 103 femmes (38,6%), âgés en moyenne de 60,2 ± 12,1 ans (extrêmes: 22 et 94 ans). Les principaux facteurs de risque cardiovasculaire identifiés étaient une hypertension artérielle (HTA) dans 214 cas (80,1%), un diabète sucré dans 36 cas (13,5%), et un tabagisme dans 18 cas (6,7%), avec un taux de cumul de 1,5 facteur par individu. L'examen Holter ECG, normal dans 216 cas (81%), était pathologique dans 51 cas (19%). Les principales anomalies enregistrées consistaient en des extrasystoles ventriculaires bénignes (n = 32), une FA paroxystique (n = 7), des extrasystoles supraventriculaires (n = 5), une tachycardie ventriculaire (TV) non soutenue (n = 4), une TV soutenue (n = 2) et un bloc auriculo-ventriculaire type Mobitz II (n = 1). La fréquence de la FA paroxystique était de 2,6%. En analyse bivariée, il n'a pas été noté de corrélation entre la FA paroxystique et le sexe (p = 0,890), l'HTA (p = 0,818), le diabète (p = 0,839), le tabac (p = 0,969). En analyse multivariée, seul l'âge était prédictif de la survenue d'une FA paroxystique au cours des infarctus cérébraux (OR = 1,11;p = 0,0134). Il ressort de cette étude préliminaire que les troubles du rythme emboligènes sont relativement rares au cours des infarctus cérébraux à Brazzaville. La FA paroxystique, quoique peu fréquente, reste essentiellement corrélée à l'âge. Sa recherche systématique chez les sujets âgés contribue à améliorer la prise en charge.

Deep Learning Approaches to Detect Atrial Fibrillation Using Photoplethysmographic Signals: Algorithms Development Study

Background

Wearable devices have evolved as screening tools for atrial fibrillation (AF). A photoplethysmographic (PPG) AF detection algorithm was developed and applied to a convenient smartphone-based device with good accuracy. However, patients with paroxysmal AF frequently exhibit premature atrial complexes (PACs), which result in poor unmanned AF detection, mainly because of rule-based or handcrafted machine learning techniques that are limited in terms of diagnostic accuracy and reliability.

Objective

This study aimed to develop deep learning (DL) classifiers using PPG data to detect AF from the sinus rhythm (SR) in the presence of PACs after successful cardioversion.

Methods

We examined 75 patients with AF who underwent successful elective direct-current cardioversion (DCC). Electrocardiogram and pulse oximetry data over a 15-min period were obtained before and after DCC and labeled as AF or SR. A 1-dimensional convolutional neural network (1D-CNN) and recurrent neural network (RNN) were chosen as the 2 DL architectures. The PAC indicator estimated the burden of PACs on the PPG dataset. We defined a metric called the confidence level (CL) of AF or SR diagnosis and compared the CLs of true and false diagnoses. We also compared the diagnostic performance of 1D-CNN and RNN with previously developed AF detectors (support vector machine with root-mean-square of successive difference of RR intervals and Shannon entropy, autocorrelation, and ensemble by combining 2 previous methods) using 10 5-fold cross-validation processes.

Results

Among the 14,298 training samples containing PPG data, 7157 samples were obtained during the post-DCC period. The PAC indicator estimated 29.79% (2132/7157) of post-DCC samples had PACs. The diagnostic accuracy of AF versus SR was 99.32% (70,925/71,410) versus 95.85% (68,602/71,570) in 1D-CNN and 98.27% (70,176/71,410) versus 96.04% (68,736/71,570) in RNN methods. The area under receiver operating characteristic curves of the 2 DL classifiers was 0.998 (95% CI 0.995-1.000) for 1D-CNN and 0.996 (95% CI 0.993-0.998) for RNN, which were significantly higher than other AF detectors (P<.001). If we assumed that the dataset could emulate a sufficient number of patients in training, both DL classifiers improved their diagnostic performances even further especially for the samples with a high burden of PACs. The average CLs for true versus false classification were 98.56% versus 78.75% for 1D-CNN and 98.37% versus 82.57% for RNN (P<.001 for all cases).

Conclusions

New DL classifiers could detect AF using PPG monitoring signals with high diagnostic accuracy even with frequent PACs and could outperform previously developed AF detectors. Although diagnostic performance decreased as the burden of PACs increased, performance improved when samples from more patients were trained. Moreover, the reliability of the diagnosis could be indicated by the CL. Wearable devices sensing PPG signals with DL classifiers should be validated as tools to screen for AF.

Ectopic Beats: Insights from Timing and Morphology

Premature complexes are electrical impulses arising from atrial, junctional, or ventricular tissue, leading to premature heart beats. Premature atrial beats are much more frequent than those arising in the atrioventricular junction but less frequent than premature beats from the ventricles. Although they are usually benign and highly prevalent in the general population, they could trigger sustained supraventricular and ventricular arrhythmias, and cause cardiomyopathies. The aim of this article was to review the main electrocardiology features of premature complexes and discuss their implications in clinical practice.

Detection of Atrial Fibrillation in Cryptogenic Stroke

PURPOSE OF REVIEW

To summarize the literature on the detection of atrial fibrillation (AF) in patients with "cryptogenic" stroke, a cohort including about 25% of all ischemic stroke patients and patients with embolic stroke of undetermined source (ESUS).

RECENT FINDINGS

A first episode of AF is detected in up to one third of cryptogenic stroke and in up to one fourth of ESUS patients during long-term monitoring. AF prevalence correlates to patient selection, duration, and quality of ECG monitoring. Higher rates of AF were reported in stroke patients with left atrial pathology, specific ECG alterations, or increased natriuretic peptides. While AF detection impacts on medical stroke prevention in the vast majority of patients, patient selection for prolonged monitoring is largely left at the physician's discretion. AF detection after cryptogenic stroke or ESUS is a frequent, potentially causal condition. Whether subsequent oral anticoagulation may improve outcome remains open.

Frequent premature atrial complexes as a predictor of atrial fibrillation: Systematic review and meta-analysis

BACKGROUND

Frequent premature atrial complexes (PACs) are associated with higher morbidity and mortality. Recent studies suggest that frequent PACs are associated with new onset atrial fibrillation (AF). However, a systematic review and meta-analysis of the literature has not been done. We assessed the association between frequent PACs and new onset AF by a systematic review and a meta-analysis.

METHODS

We comprehensively searched the databases of MEDLINE and EMBASE from inception to September 2017. Included studies were published cohort (prospective or retrospective) that compared new onset AF among patients with and without frequent PACs documented by Holter monitoring or 12-lead electrocardiogram. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian and Laird to calculate risk ratios and 95% confidence intervals.

RESULTS

Twelve studies from 2009 to 2017 were included in this meta-analysis involving 109,689 subjects (9217frequent and 100,472 non-frequent PACs). Frequent PACs were associated with increased risk of new onset AF (pooled risk ratio = 2.76, 95% confidence interval: 2.05-3.73, p < 0.000, I² = 90.6%).

CONCLUSION

Frequent PACs are associated with up to three-fold increased risk of new onset AF. Our study suggests that frequent PACs in general population is an independent predictor of new onset AF.

Electrocardiogram (ECG) for the Prediction of Incident Atrial Fibrillation: An Overview

Electrocardiograms (ECGs) have been employed to medically evaluate participants in population-based studies, and ECG-derived predictors have been reported for incident atrial fibrillation (AF). Here, we reviewed the status of ECG in predicting new-onset AF. We surveyed population-based studies and revealed ECG variables to be risk factors for incident AF. When available, the predictive values of each ECG risk marker were calculated. Both the atrium-related and ventricle-related ECG variables were risk factors for incident AF, with significant hazard risks (HRs) even after multivariate adjustments. The risk factors included P-wave indices (maximum P-wave duration, its dispersion or variation and P-wave morphology) and premature atrial contractions (PACs) or runs. In addition, left ventricular hypertrophy (LVH), ST-T abnormalities, intraventricular conduction delay, QTc interval and premature ventricular contractions (PVCs) or runs were a risk of incident AF. An HR of greater than 2.0 was observed in the upper 5th percentile of the P-wave durations, P-wave durations greater than 130 ms, P-wave morpholyg, PACs (PVCs) or runs, LVH, QTc and left anterior fascicular blocks. The sensitivity , specificity and the positive and negative predictive values were 3.6-53.8%, 61.7-97.9%, 2.9-61.7% and 77.4-97.7%, respectively. ECG variables are risk factors for incident AF. The correlation between the ECG-derived AF predictors, especially P-wave indices, and underlying diseases and the effects of the reversal of the ECG-derived predictors on incident AF by treatment of comorbidities require further study.

Atrial ectopy and N-terminal pro-B-type natriuretic peptide as predictors of atrial fibrillation: a population-based cohort study

Aims

The risk of incident atrial fibrillation (AF) can be estimated by clinical parameters in the Framingham AF risk model. Elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) and increased rate of premature atrial contractions (PACs) have been shown to be associated with AF, but the additive value of both of these biomarkers in the Framingham AF risk model has not been fully examined.

Methods and results

A total of 646 subjects from the Copenhagen Holter Study (mean age 64.4 ± 6.8 years, 41.6% women) with no history of prior AF, stroke or cardiovascular disease were followed for the diagnosis of incident AF or death (median follow-up time 14.4 years). Median NT-proBNP was 6.7 pmol/L (IQR: 3.6-13.5), median PAC count was 1.4 beats/h (IQR: 0.6-4.5), 71 (11.0%) subjects developed AF, and 244 (37.8%) died. Multiple Cox regression including Framingham AF risk score, log-transformed NT-proBNP, and log-transformed PAC showed a significant increase in AF hazard risk [hazard ratio (HR) 1.45, 95% confidence interval (CI) 1.14-1.85, P = 0.002; HR 1.23, 95% CI 1.09-1.39, P = 0.001]. The addition of PAC to the Framingham AF risk model significantly improved the time-dependent area under the receiver operating characteristic curve (AUC 65.6 vs. 72.6; P = 0.008), while the addition of NT-proBNP did not.

Conclusion

Atrial fibrillation risk discrimination was significantly improved by the addition of PAC to the Framingham AF risk model, but not by the addition of NT-proBNP.

ECTOPIC BEATS: HOW MANY COUNT?

Premature atrial and ventricular contractions, or ectopic beats, are frequently detected on routine electrocardiogram monitoring. They are often considered to be benign with no pathological significance; however, the literature suggests that higher ectopic burdens may have clinical importance. This paper reviews the current literature and provides the treating physician with an understanding of when ectopic beats should be deemed significant and when treatment may be appropriate.

Screening strategies for atrial fibrillation: a systematic review and cost-effectiveness analysis

Background

Atrial fibrillation (AF) is a common cardiac arrhythmia that increases the risk of thromboembolic events. Anticoagulation therapy to prevent AF-related stroke has been shown to be cost-effective. A national screening programme for AF may prevent AF-related events, but would involve a substantial investment of NHS resources.

Objectives

To conduct a systematic review of the diagnostic test accuracy (DTA) of screening tests for AF, update a systematic review of comparative studies evaluating screening strategies for AF, develop an economic model to compare the cost-effectiveness of different screening strategies and review observational studies of AF screening to provide inputs to the model.

Design

Systematic review, meta-analysis and cost-effectiveness analysis.

Setting

Primary care.

Participants

Adults.

Intervention

Screening strategies, defined by screening test, age at initial and final screens, screening interval and format of screening {systematic opportunistic screening [individuals offered screening if they consult with their general practitioner (GP)] or systematic population screening (when all eligible individuals are invited to screening)}.

Main outcome measures

Sensitivity, specificity and diagnostic odds ratios; the odds ratio of detecting new AF cases compared with no screening; and the mean incremental net benefit compared with no screening.

Review methods

Two reviewers screened the search results, extracted data and assessed the risk of bias. A DTA meta-analysis was perfomed, and a decision tree and Markov model was used to evaluate the cost-effectiveness of the screening strategies.

Results

Diagnostic test accuracy depended on the screening test and how it was interpreted. In general, the screening tests identified in our review had high sensitivity (> 0.9). Systematic population and systematic opportunistic screening strategies were found to be similarly effective, with an estimated 170 individuals needed to be screened to detect one additional AF case compared with no screening. Systematic opportunistic screening was more likely to be cost-effective than systematic population screening, as long as the uptake of opportunistic screening observed in randomised controlled trials translates to practice. Modified blood pressure monitors, photoplethysmography or nurse pulse palpation were more likely to be cost-effective than other screening tests. A screening strategy with an initial screening age of 65 years and repeated screens every 5 years until age 80 years was likely to be cost-effective, provided that compliance with treatment does not decline with increasing age.

Conclusions

A national screening programme for AF is likely to represent a cost-effective use of resources. Systematic opportunistic screening is more likely to be cost-effective than systematic population screening. Nurse pulse palpation or modified blood pressure monitors would be appropriate screening tests, with confirmation by diagnostic 12-lead electrocardiography interpreted by a trained GP, with referral to a specialist in the case of an unclear diagnosis. Implementation strategies to operationalise uptake of systematic opportunistic screening in primary care should accompany any screening recommendations.

Limitations

Many inputs for the economic model relied on a single trial [the Screening for Atrial Fibrillation in the Elderly (SAFE) study] and DTA results were based on a few studies at high risk of bias/of low applicability.

Future work

Comparative studies measuring long-term outcomes of screening strategies and DTA studies for new, emerging technologies and to replicate the results for photoplethysmography and GP interpretation of 12-lead electrocardiography in a screening population.

Study registration

This study is registered as PROSPERO CRD42014013739.

Funding

The National Institute for Health Research Health Technology Assessment programme.

Holter-electrocardiogram-monitoring in patients with acute ischaemic stroke (Find-AFRANDOMISED): an open-label randomised controlled trial

BACKGROUND

Atrial fibrillation is a major risk factor for recurrent ischaemic stroke, but often remains undiagnosed in patients who have had an acute ischaemic stroke. Enhanced and prolonged Holter-electrocardiogram-monitoring might increase detection of atrial fibrillation. We therefore investigated whether enhanced and prolonged rhythm monitoring was better for detection of atrial fibrillation than standard care procedures in patients with acute ischaemic stroke.

METHODS

Find-AF_randomised is an open-label randomised study done at four centres in Germany. We recruited patients with acute ischaemic stroke (symptoms for 7 days or less) aged 60 years or older presenting with sinus rhythm and without history of atrial fibrillation. Patients were included irrespective of the suspected cause of stroke, unless they had a severe ipsilateral carotid or intracranial artery stenosis, which were the exclusion criteria. We used a computer-generated allocation sequence to randomly assign patients in a 1:1 ratio with permuted block sizes of 2, 4, 6, and 8, stratified by centre, to enhanced and prolonged monitoring (ie, 10-day Holter-electrocardiogram [ECG]-monitoring at baseline, and at 3 months and 6 months of follow-up) or standard care procedures (ie, at least 24 h of rhythm monitoring). Participants and study physicians were not masked to group assignment, but the expert committees that adjudicated endpoints were. The primary endpoint was the occurrence of atrial fibrillation or atrial flutter (30 sec or longer) within 6 months after randomisation and before stroke recurrence. Because Holter ECG is a widely used procedure and not known to harm patients, we chose not to assess safety in detail. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01855035.

FINDINGS

Between May 8, 2013, and Aug 31, 2014, we recruited 398 patients. 200 patients were randomly assigned to the enhanced and prolonged monitoring group and 198 to the standard care group. After 6 months, we detected atrial fibrillation in 14% of 200 patients in the enhanced and prolonged monitoring group (27 patients) versus 5% in the control group (nine of 198 patients, absolute difference 9·0%; 95% CI 3·4-14·5, p=0·002; number needed to screen 11).

INTERPRETATION

Enhanced and prolonged monitoring initiated early in patients with acute ischaemic stroke aged 60 years or older was better than standard care for the detection of atrial fibrillation. These findings support the consideration of all patients aged 60 years or older with stroke for prolonged monitoring if the detection of atrial fibrillation would result in a change in medical management (eg, initiation of anticoagulation).

FUNDING

Boehringer Ingelheim.

Excessive Premature Atrial Complexes and the Risk of Recurrent Stroke or Death in an Ischemic Stroke Population

BACKGROUND

Our aim was to investigate the association of premature atrial complexes and the risk of recurrent stroke or death in patients with ischemic stroke in sinus rhythm.

METHODS

In a prospective cohort study, we used 24-hour Holter recordings to evaluate premature atrial complexes in patients consecutively admitted with ischemic strokes. Excessive premature atrial complexes were defined as >14 premature atrial complexes per hour and 3 or more runs of premature atrial complexes per 24 hours. During follow-up, 48-hour Holter recordings were performed after 6 and 12 months. Among patients in sinus rhythm, the association of excessive premature atrial complexes and the primary end point of recurrent stroke or death were estimated in both crude and adjusted Cox proportional hazards models. We further evaluated excessive premature atrial complexes contra atrial fibrillation in relation to the primary end point.

RESULTS

Of the 256 patients included, 89 had atrial fibrillation. Of the patients in sinus rhythm (n = 167), 31 had excessive premature atrial complexes. During a median follow-up of 32 months, 50 patients (30% of patients in sinus rhythm) had recurrent strokes (n = 20) or died (n = 30). In both crude and adjusted models, excessive premature atrial complexes were associated with the primary end point, but not with newly diagnosed atrial fibrillation. Compared with patients in atrial fibrillation, those with excessive premature atrial complexes had similarly high risks of the primary end point.

CONCLUSIONS

In patients with ischemic stroke and sinus rhythm, excessive premature atrial complexes were associated with a higher risk of recurrent stroke or death.

Electrocardiographic and Echocardiographic predictors of paroxysmal atrial fibrillation detected after ischemic stroke

BACKGROUND

Detection of atrial fibrillation after ischemic stroke is challenging due to its paroxysmal nature. We aimed to assess predictors of paroxysmal atrial fibrillation using non-invasive surface ECG and transthoracic echocardiography to select candidates for atrial fibrillation screening.

METHODS

Ischemic stroke patients without documented atrial fibrillation (n = 110, 67 ± 10 years, 40 female) and a control group of age- and gender-matched patients with history of paroxysmal atrial fibrillation prior to stroke (n = 55, 67 ± 10 years, 19 female) comprised the study sample. Using non-invasive ECG monitoring for three weeks, short episodes of paroxysmal atrial fibrillation were detected in 24 of 110 patients (22 %). The standard 12-lead ECG with sinus rhythm at stroke onset was digitally processed and analyzed. Transthoracic echocardiography data were reviewed for these patients.

RESULTS

Atrial fibrillation history was independently associated with P terminal force in lead V 1 > 40 mm*ms (OR 4.04 95 % CI 1.34-12.14, p = 0.013) and left atrial volume index (OR 1.08 95 % CI 1.03-1.13, p = 0.002; for LAVI > 40 mL/m² OR 6.40 95 % CL 1.47-27.91, p = 0.013). Among patients without atrial fibrillation history, no ECG characteristics were predictive of atrial fibrillation detected after stroke. Left atrial volume index remained an independent predictor of atrial fibrillation detected after stroke (OR 1.09 95 % CI 1.02-1.16, p = 0.017). A cutoff of <40 mL/m² had an 84 % negative predictive value for ruling out atrial fibrillation on ambulatory monitoring with a sensitivity of 50 % and a specificity of 86 %.

CONCLUSION

In a post hoc analysis, left atrial dilatation assessed by left atrial volume index independently predicted atrial fibrillation after stroke in patients without prior atrial fibrillation history, while the other clinical or ECG markers were not predictive of atrial fibrillation detected early after ischemic stroke.

TRIAL REGISTRATION

This study is a post hoc analysis from the prospective case-control study registered in December 2011, ClinicalTrials.gov ID: NCT01325545 .

B-Type Natriuretic Peptide Modulates Pulmonary Vein Arrhythmogenesis: A Novel Potential Contributor to the Genesis of Atrial Tachyarrhythmia in Heart Failure

BACKGROUND

Heart failure (HF) plays a critical role in the genesis of atrial fibrillation (AF). A high B-type natriuretic peptide (BNP) level occurs in patients with HF and in patients with AF. However, the role of BNP in the pathophysiology of AF is not clear. The purposes of this study were to evaluate the effects of BNP on pulmonary vein (PV) arrhythmogenesis.

METHODS AND RESULTS

Whole-cell patch clamp and fluorescence were used to study the action potential, ionic currents, and calcium homeostasis in isolated single rabbit PV cardiomyocytes before and after a BNP infusion, with or without ODQ (10 μM), milrinone (50 μM), or ouabain (1 μM). BNP increased PV spontaneous activity by 28.2 ± 7.5% at 100 nM and by 23.8 ± 9.1% at 300 nM. Similar to those with BNP, milrinone 50 μM increased the PV beating rate from 3.0 ± 0.2 to 3.6 ± 0.3 Hz (P < 0.0005, n = 7). In the presence of ODQ application, BNP didn't change PV spontaneous activity. BNP (100 nM) increased calcium transients (F/F₀ from 1.6 ± 0.1 to 1.9 ± 0.2, n = 20, P < 0.05) and increased the pacemaker current (0.4 ± 0.1 to 1.0 ± 0.2 pA/pF, n = 17, P < 0.0005) in PV cardiomyocytes. Moreover, BNP (100 nM) increased the transient inward current, sodium currents, sodium-calcium exchanger currents, and L-type calcium current; but reduced late sodium currents and the Na-K pump in PV cardiomyocytes.

CONCLUSION

BNP increases PV arrhythmogenesis, which may contribute to the genesis of atrial tachyarrhythmogenesis in HF. Cyclic GMP activation, phosphodiesterase 3 inhibition and Na⁺ /K⁺ -ATPase inhibition might participate in the BNP modulation of PV electrophysiology.

Detection of Atrial Fibrillation Among Patients With Stroke Due to Large or Small Vessel Disease: A Meta-Analysis

BACKGROUND

Recent trials have demonstrated that extended cardiac monitoring increases the yield of paroxysmal atrial fibrillation (AF) detection in patients with cryptogenic stroke. The utility of extended cardiac monitoring is uncertain among patients with stroke caused by small and large vessel disease. We conducted a meta-analysis to estimate the yield of AF detection in this population.

METHODS AND RESULTS

We searched PubMed, Cochrane, and SCOPUS databases for studies on AF detection in stroke patients and excluded studies restricted to patients with cryptogenic stroke or transient ischemic attack. We abstracted AF detection rates for 3 populations grouped by stroke etiology: large vessel stroke, small vessel stroke, and stroke of undefined etiology (a mixture of cryptogenic, small vessel, large vessel, and other stroke etiologies). Our search yielded 30 studies (n=5687). AF detection rates were similar in patients with large vessel (2.2%, 95% CI 0.3-5.5; n=830) and small vessel stroke (2.4%, 95% CI 0.4-6.1; n=520). No studies had a monitoring duration longer than 7 days. The yield of AF detection in the undefined stroke population was higher (9.2%; 95% CI 7.1-11.5) compared to small vessel stroke (P=0.02) and large vessel stroke (P=0.02) populations.

CONCLUSIONS

AF detection rate is similar in patients with small and large vessel strokes (2.2-2.4%). Because no studies reported on extended monitoring (>7 days) in these stroke populations, we could not estimate the yield of AF detection with long-term cardiac monitoring. Randomized controlled trials are needed to examine the utility of AF detection with long-term cardiac monitoring (>7 days) in this patient population.

Long-term Arrhythmia Monitoring in Cryptogenic Stroke: Who, How, and for How Long?

Cryptogenic stroke and transient ischemic attack (TIA) account for approximately one-third of stroke patients [1]. Paroxys-mal atrial fibrillation (PAF) has been suggested as a major etiology of these cryptogenic strokes [2, 3]. PAF can be difficult to diagnose because it is intermittent, often brief, and asymptomatic. PAF might be more prevalent than persistent atrial fibrillation in stroke and TIA patients, especially in younger populations [4, 5]. In patients with atrial fibrillation, anticoagulation provides significant risk reduction [6]. A new generation of oral anticoagulants has been approved for non-valvular atrial fibrillation, providing a variety of therapeutic options for patients with atrial fibrillation and risk of stroke [7]. Prior practice included an admission electrocardiogram (ECG) and continuous telemetry monitoring while in hospital [8]. However, this approach can lead to under-detection of brief asymptomatic events, which can occur at variable intervals, often outside of the hospital setting. Technological advancements have led to devices that can monitor cardiac rhythms outside of the hospital for longer durations resulting in higher yield of detection of atrial fibrillation events. Moreover, recent studies show that the normal monitoring time for arrhythmias may be shorter than ideal in order to detect atrial fibrillation, and increasing this interval could significantly improve detection of atrial fibrillation in these patients [9, 10]. The aim of this study is to review the literature in order to define what subgroup of patients, with what methodologies, and for how long monitoring for atrial fibrillation should occur in patients presenting with cryptogenic stroke.

Prevalence and Prognostic Significance of Runs of Premature Atrial Complexes in Ischemic Stroke Patients

BACKGROUND AND PURPOSE

Runs of premature atrial complexes (PACs) are common in stroke patients and perceived to be clinically insignificant, but their prognostic significance is unclear. This study investigated the association between runs of PACs in ischemic stroke patients and the risk of recurrent ischemic strokes/transient ischemic attacks (TIAs) or death.

METHODS

The study included consecutive patients admitted with an ischemic stroke from August 2008 to April 2011. Patients with known and newly detected atrial fibrillation were excluded. Runs of PACs were defined as 3 or more PACs lasting less than 30 seconds during 48 hours of continuous inpatient cardiac telemetry. The patients were followed for 4 years or until death, whichever came first. They were stratified according to stroke severity. The combined primary endpoint was a recurrent ischemic stroke/TIA or death.

RESULTS

Of the 565 patients included in the study, 28% had runs of PACs. Patients with runs of PACs were likely to be older, female, and to have experienced more severe strokes. During the follow-up, 210 (37%) patients had a recurrent ischemic stroke/TIA (n = 73) or died (n = 137) respectively. Among the 489 patients who had mild-to-moderate strokes, runs of PACs were associated with recurrent ischemic strokes/TIAs or death (hazard ratio = 1.47; 95% CI 1.06-2.04; P = .023).

CONCLUSION

Runs of PACs were frequent in patients with acute ischemic strokes and sinus rhythm, and they were independently associated with an increased risk of recurrent ischemic strokes/TIAs or death in patients with mild-to-moderate strokes.

Optimal Duration of Monitoring for Atrial Fibrillation in Cryptogenic Stroke: A Nonsystematic Review

Atrial fibrillation (AF) is the most common form of cardiac arrhythmias and an independent risk factor for stroke. Despite major advances in monitoring strategies, clinicians tend to miss the diagnoses of AF and especially paroxysmal AF due mainly to its asymptomatic presentation and the rather limited duration dedicated for monitoring for AF after a stroke, which is 24 hours as per the current recommended guidelines. Hence, determining the optimal duration of monitoring for paroxysmal atrial fibrillation after acute ischemic stroke remains a matter of debate. Multiple trials were published in regard to this matter using both invasive and noninvasive monitoring strategies for different monitoring periods. The data provided by these trials showcase strong evidence suggesting a longer monitoring strategy beyond 24 hours is associated with higher detection rates of AF, with the higher percentage of patients detected consequently receiving proper secondary stroke prevention with anticoagulation and thus justifying the cost-effectiveness of such measures. Overall, we thus conclude that increasing the monitoring duration for AF after a cryptogenic stroke to at least 72 hours will indeed enhance the detection rates, but the cost-effectiveness of this monitoring strategy compared to longer monitoring durations is yet to be established.