Excessive Supraventricular Ectopic Activity in Patients With Acute Ischemic Stroke Is Associated With Atrial Fibrillation Detection Within 24 Months After Stroke: A Predefined Analysis of the MonDAFIS Study

BACKGROUND

Excessive supraventricular ectopic activity (ESVEA) is regarded as a risk marker for later atrial fibrillation (AF) detection.

METHODS AND RESULTS

The investigator-initiated, prospective, open, multicenter MonDAFIS (Impact of Standardized Monitoring for Detection of Atrial Fibrillation in Ischemic Stroke) study randomized 3465 patients with acute ischemic stroke without known AF 1:1 to usual diagnostic procedures for AF detection or additive Holter monitoring in hospital for up to 7 days, analyzed in a core laboratory. Secondary study objectives include the comparison of recurrent stroke, myocardial infarction, major bleeding, and all-cause death within 24 months in patients with ESVEA (defined as ectopic supraventricular beats ≥480/day or atrial runs of 10-29 seconds or both) versus patients with newly diagnosed AF versus patients without ESVEA or AF (non-ESVEA/AF), randomized to the intervention group. Overall, 1435 (84.8%) of 1714 patients randomized to the intervention group had analyzable study ECG monitoring of at least 48 hours' duration within the first 72 hours of monitoring. ESVEA was detected in 363 (25.3%) patients, while AF was first detected in 48 (3.3%) patients. Within 24 months, AF was newly detected in 67 (18.5%) patients with ESVEA versus 60 (5.9%) patients without ESVEA/AF- (P<0.001). The composite outcome at 24 months was not different between patients with ESVEA and patients without ESVEA/AF (15.2% versus 12.6%; P=0.242). All-cause death was numerically higher in patients with ESVEA (6.6% versus 3.2%), but failed statistical significance (P=0.433) in multivariate analysis (including age, heart failure, stroke severity, and creatinine at baseline).

CONCLUSIONS

ESVEA in the acute phase of ischemic stroke or transient ischemic attack is associated with AF detection during follow-up and therefore may be used to select patients for prolonged ECG monitoring.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02204267.

Shorter Premature Atrial Complex Coupling Interval Leads to Mechanical Dysfunction, Fibrosis, and AF in Swine

BACKGROUND

We have previously shown that dyssynchronous premature atrial complexes (PACs) from the lateral left atrium (LA) lead to greater atrial mechanical dysfunction, remodeling, and sustained atrial fibrillation (AF) than synchronous PACs from the interatrial septum. However, the impact of PAC coupling interval (CI) on atrial remodeling is unclear.

OBJECTIVES

This study sought to explore the effect of PAC CI on atrial mechanics and remodeling in the swine model.

METHODS

A 2-phase in vivo study was conducted. In the phase 1 acute study, 5 swine underwent acute invasive hemodynamics and echocardiography while delivering single-paced atrial extrastimuli with CIs varying from 450 ms to 200 ms. Peak LA longitudinal strain and intra-LA dyssynchrony were assessed with 2-dimensional strain echocardiography while LA and aortic pressure were directly measured. In the phase 2 chronic study, a group exposed to paced bigeminy from the lateral LA for 16 weeks with a short CI of 250 ms (Short-PAC, n = 10) was compared with groups with PACs at a long CI of 400 ms (Long-PAC, n = 5) and a nonpaced control group (CTRL, n = 10). Detailed electrophysiology and echocardiography studies were performed with histologic quantification of LA fibrosis at baseline and prior to sacrifice.

RESULTS

Phase 1 revealed that as PAC CI shortened, peak LA strain decreased (P = 0.003) and LA dyssynchrony increased (P < 0.001). Phase 2 showed that after 16 weeks of PACs, the Short-PAC group had greater LA dilation (terminal baseline: 5.9 ± 1.2 cm2 vs Long-PAC 3.9 ± 0.5 cm2 vs CTRL 0.9 ± 0.4 cm2; P < 0.001) and reduced peak LA strain during sinus rhythm (terminal baseline: -17.3% ± 3.2% vs Long-PAC -12.1% ± 2.1% vs CTRL -0.7% ± 4.2%; P < 0.001). The short-PAC group had a more LA fibrosis (8.6% ± 1.0% vs Long-PAC 6.8% ± 1.0% vs CTRL 4.0% ± 1.5%; P < 0.001) and higher AF inducibility (terminal baseline: 49.3% ± 13.0% vs Long-PAC 29.0% ± 6.4% vs CTRL 2.2% ± 16.2%; P < 0.001) than the other groups.

CONCLUSIONS

In this swine model, shorter PAC CI led to increased acute atrial mechanical dysfunction and dyssynchrony. Chronically, short-CI PACs led to greater atrial fibrosis and induced AF, suggesting that frequent, short-coupled PACs pose the highest risk for LA myopathy and AF. These insights underscore the importance of understanding the impact of PAC characteristics on atrial remodeling and arrhythmogenesis.

Detection of Non-Sustained Supraventricular Tachycardia in Atrial Fibrillation Screening

OBJECTIVE

Non-sustained supraventricular tachycardia (nsSVT) is associated with a higher risk of developing atrial fibrillation (AF), and, therefore, detection of nsSVT can improve AF screening efficiency. However, the detection is challenged by the lower signal quality of ECGs recorded using handheld devices and the presence of ectopic beats which may mimic the rhythm characteristics of nsSVT.

METHODS

The present study introduces a new nsSVT detector for use in single-lead, 30-s ECGs, based on the assumption that beats in an nsSVT episode exhibits similar morphology, implying that episodes with beats of deviating morphology, either due to ectopic beats or noise/artifacts, are excluded. A support vector machine is used to classify successive 5-beat sequences in a sliding window with respect to similar morphology. Due to the lack of adequate training data, the classifier is trained using simulated ECGs with varying signal-to-noise ratio. In a subsequent step, a set of rhythm criteria is applied to similar beat sequences to ensure that episode duration and heart rate is acceptable.

RESULTS

The performance of the proposed detector is evaluated using the StrokeStop II database, resulting in sensitivity, specificity, and positive predictive value of 84.6%, 99.4%, and 18.5%, respectively.

CONCLUSION

The results show that a significant reduction in expert review burden (factor of 6) can be achieved using the proposed detector.Clinical and Translational Impact: The reduction in the expert review burden shows that nsSVT detection in AF screening can be made considerably more efficiently.

Electrocardiogram prediction of atrial fibrillation risk after stroke: A protocol for systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is one of the most common clinical arrhythmias. This study aims to predict the risk of post-stroke AF through electrocardiographic changes in sinus rhythm.

METHODS

We searched the MEDLINE (PubMed) and EMBASE databases to identify relevant research articles published until August 2023. Prioritized items from systematic reviews and meta-analyses were screened, and data related to AF detection rate were extracted. A meta-analysis using a random-effects model was conducted for data synthesis and analysis.

RESULTS

A total of 32 studies involving electrocardiograms (ECG) were included, with a total analysis population of 330,284 individuals. Among them, 16,662 individuals (ECG abnormal group) developed AF, while 313,622 individuals (ECG normal group) did not. ECG patterns included terminal P-wave terminal force V1, interatrial block (IAB), advanced interatrial block, abnormal P-wave axis, pulse rate prolongation, and atrial premature complexes. Overall, 15,762 patients experienced AF during the study period (4.77%). In the ECG abnormal group, the proportion was 14.21% (2367/16,662), while in the control group (ECG normal group), the proportion was 4.27% (13,395/313,622). The pooled risk ratio for developing AF was 2.45 (95% confidence interval [CI]: 2.02-2.98, P < .001), with heterogeneity (I2) of 95%. The risk ratio values of alAB, P-wave terminal force V1, interatrial block, abnormal P-wave axis, pulse rate prolongation and atrial premature complexes were 4.12 (95% CI, 2.99-5.66), 1.47 (95% CI, 1.19-1.82), 2.54 (95% CI, 1.83-3.52), 1.70 (95% CI, 0.98-2.97), 2.65 (95% CI, 1.88-3.72), 3.79 (95% CI, 2.12-6.76), respectively.

CONCLUSION

There is a significant correlation between ECG patterns and the occurrence of AF. The alAB exhibited the highest level of predictability for the occurrence of AF. These indicators support their use as screening tools to identify high-risk individuals who may benefit from further examinations or empirical anticoagulation therapy following stroke.

Frequent Premature Atrial Contractions Lead to Adverse Atrial Remodeling and Atrial Fibrillation in a Swine Model

BACKGROUND

Frequent premature atrial complexes (PACs) are associated with future incident atrial fibrillation (AF), but whether PACs contribute to development of AF through adverse atrial remodeling has not been studied. This study aimed to explore the effect of frequent PACs from different sites on atrial remodeling in a swine model.

METHODS

Forty swine underwent baseline electrophysiologic studies and echocardiography followed by pacemaker implantations and paced PACs (50% burden) at 250-ms coupling intervals for 16 weeks in 4 groups: (1) lateral left atrium (LA) PACs by the coronary sinus (Lat-PAC; n=10), (2) interatrial septal PACs (Sep-PAC; n=10), (3) regular LA pacing at 130 beats/min (Reg-130; n=10), and (4) controls without PACs (n=10). At the final study, repeat studies were performed, followed by tissue histology and molecular analyses focusing on fibrotic pathways.

RESULTS

Lat-PACs were associated with a longer P-wave duration (93.0±9.0 versus 74.2±8.2 and 58.8±7.6 ms; P<0.001) and greater echocardiographic mechanical dyssynchrony (57.5±11.6 versus 35.7±13.0 and 24.4±11.1 ms; P<0.001) compared with Sep-PACs and controls, respectively. After 16 weeks, Lat-PACs led to slower LA conduction velocity (1.1±0.2 versus 1.3±0.2 [Sep-PAC] versus 1.3±0.1 [Reg-130] versus 1.5±0.2 [controls] m/s; P<0.001) without significant change in atrial ERP. The Lat-PAC group had a significantly increased percentage of LA fibrosis and upregulated levels of extracellular matrix proteins (lysyl oxidase and collagen 1 and 8), as well as TGF-β1 (transforming growth factor-β1) signaling proteins (latent and monomer TGF-β1 and phosphorylation/total ratio of SMAD2/3; P<0.05). The Lat-PAC group had the longest inducible AF duration (terminal to baseline: 131 [interquartile range 30, 192] seconds versus 16 [6, 26] seconds [Sep-PAC] versus 22 [11, 64] seconds [Reg-130] versus -1 [-16, 7] seconds [controls]; P<0.001).

CONCLUSIONS

In this swine model, frequent PACs resulted in adverse atrial structural remodeling with a heightened propensity to AF. PACs originating from the lateral LA produced greater atrial remodeling and longer induced AF duration than the septal-origin PACs. These data provide evidence that frequent PACs can cause adverse atrial remodeling as well as AF, and that the location of ectopic PACs may be clinically meaningful.

Longitudinal association of premature atrial contractions with atrial fibrillation and brain ischemia in people with type 2 diabetes: The Hoorn Diabetes Care System cohort

Background

Premature atrial contractions (PACs) are potential markers for imminent onset of both atrial fibrillation (AF) and brain ischemia (BI; transient ischemic attack [TIA] or ischemic stroke). We investigated the association of PACs with incident AF and BI events separately, and of incident AF with BI events in people with type 2 diabetes (T2D) without pre-existing AF or cerebrovascular disease.

Methods

A prospective longitudinal study of 12,242 people with T2D without known AF or cerebrovascular disease from the Hoorn Diabetes Care System cohort. Annual measurements (1998-2018) included cardiovascular risk factors, over 85,000 ECGs, and self-reported cardiovascular events. We assessed the association of PACs with incident AF and BI events and of incident AF with BI events using time-dependent Cox-regression models, adjusted for time-varying cardiovascular risk factors and medication use (Hazard Ratios with 95%CIs).

Results

The baseline mean age was 62.2 ± 11.9 years. During a median follow-up of 7.0 (IQR 3.4-11.0) years, 1031 (8.4 %) participants had PACs, and 566 (4.6 %) had incident AF at any of the median 6 (IQR 3-10) annual ECG recordings. BI events occurred in 517 (4.2 %) people (304 TIAs, 213 ischemic strokes). After adjustment, PACs were associated with incident AF (Hazard Ratio, 1.96 (95%CI, 1.53-2.50)), but not with overall BI events (1.09 (0.76-1.56)), or with TIA (0.91 (0.57-1.46)) or ischemic stroke (1.50 (0.88-2.54)) separately. AF was not associated with BI events (0.95 (0.55-1.63)).

Conclusions

In people with T2D without a history of AF or BI events, PACs are associated with a two-fold increased risk of incident AF.

Predicting risk of AF in ischaemic stroke using sinus rhythm ECG abnormalities: A meta-analysis

OBJECTIVE

To identify ECG changes in sinus rhythm that may be used to predict subsequent development of new AF.

METHOD

We identified prospective and retrospective cohort or case control studies evaluating ECG patterns from a 12-lead ECG in sinus rhythm taken in hospital or community predicting subsequent development of new AF. For each identified ECG predictor, we then identify absolute event rates and pooled risk ratios (RR) using an aggregate level random effects meta-analysis.

RESULTS

We identified 609,496 patients from 22 studies. ECG patterns included P wave terminal force V1 (PTFV1), interatrial block (IAB) and advanced interatrial block (aIAB), abnormal P wave axis (aPWA), PR prolongation and atrial premature complexes (APCs). Pooled risk ratios reached significance for each of these; PTFV1 RR 1.48 (95% CI 1.04-2.10), IAB 2.54 (95% CI 1.64-3.93), aIAB 4.05 (95% CI 2.64-6.22), aPWA 1.89 (95% CI 1.25-2.85), PR prolongation 2.22 (95% CI 1.27-3.87) and APCs 3.71 (95% CI 2.23-6.16). Diabetes reduced the predictive value of PR prolongation.

CONCLUSION

APC and aIAB were most predictive of AF, while IAB, PR prolongation, PTFV1 and aPWA were also significantly associated with development of AF. These support their use in a screening tool to identify at risk cohorts who may benefit from further investigation, or following stroke, with empirical anticoagulation.

Age and gender differences of basic electrocardiographic values and abnormalities in the general adult population; Tehran Cohort Study

BACKGROUND

Although several studies are available regarding baseline Electrocardiographic (ECG) parameters and major and minor ECG abnormalities, there is considerable controversy regarding their age and gender differences in the literature.

METHODS

Data from 7630 adults aged ≥ 35 from the Tehran Cohort Study registered between March 2016 and March 2019 were collected. Basic ECG parameters values and abnormalities related to arrhythmia, defined according to the American Heart Association definitions, were analyzed and compared between genders and four distinct age groups. The odds ratio of having any major ECG abnormality between men and women, stratified by age, was calculated.

RESULTS

The average age was 53.6 (± 12.66), and women made up 54.2% (n = 4132) of subjects. The average heart rate (HR) was higher among women(p < 0.0001), while the average values of QRS duration, P wave duration, and RR intervals were higher among men(p < 0.0001). Major ECG abnormalities were observed in 2.9% of the study population (right bundle branch block, left bundle branch block, and Atrial Fibrillation were the most common) and were more prevalent among men compared to women but without statistical significance (3.1% vs. 2.7% p = 0.188). Moreover, minor abnormalities were observed in 25.9% of the study population and again were more prevalent among men (36.4% vs. 17% p < 0.001). The prevalence of major ECG abnormalities was significantly higher in participants older than 65.

CONCLUSION

Major and minor ECG abnormalities were roughly more prevalent in male subjects. In both genders, the odds of having major ECG abnormalities surge with an increase in age.

High-Burden Premature Atrial Contractions Predict New-Onset Atrial Fibrillation After Surgical Septal Myectomy

Although increased premature atrial contractions (PACs) reportedly predict atrial fibrillation (AF) in both general and specific (e.g., patients with stroke) populations, early postoperative AF (POAF) risk in patients with increased PAC burden who require cardiac surgery remains unclear. We examined the correlation between different preoperative PAC burdens and POAF in patients with obstructive hypertrophic cardiomyopathy (OHCM) who underwent surgical treatment. We analyzed 304 consecutively admitted patients with OHCM without previous AF who underwent isolated septal myectomy between January 2015 and December 2018. All patients underwent preoperative 24-hour Holter electrocardiogram monitoring. PACs were present in 259 patients (85.20%) and absent in 45 patients (14.80%). According to the cut-off PAC number of 100 beats/24 hours, there were 211 patients (69.41%) with low-burden PACs and 48 patients (15.79%) with high-burden PACs. AF after septal myectomy occurred in 73 patients, which consisted of 3/45 in the non-PAC group (6.67%), 47/211 in the low-PAC-burden group (22.27%), and 23/48 in the high PAC burden group (47.92%). POAF incidence was higher in both low- and high-burden patients than in patients without PAC (p <0.01). Multivariate logistic regression analyses demonstrated that high-burden PACs (p = 0.02) and age (p <0.01) but not low-burden PACs (p = 0.22) independently predicted POAF in patients with OHCM. The area under the receiver operating characteristic curve for preoperative PACs was 0.72 (95% confidence interval 0.66 to 0.79, p <0.01, sensitivity: 68.49%, specificity: 69.26%). In conclusion, POAF incidence was significantly higher in patients with preoperative high-burden PACs and can predict POAF in patients with OHCM.

Premature atrial and ventricular contractions detected on wearable-format electrocardiograms and prediction of cardiovascular events

Aims

Wearable devices are transforming the electrocardiogram (ECG) into a ubiquitous medical test. This study assesses the association between premature ventricular and atrial contractions (PVCs and PACs) detected on wearable-format ECGs (15 s single lead) and cardiovascular outcomes in individuals without cardiovascular disease (CVD).

Methods and results

Premature atrial contractions and PVCs were identified in 15 s single-lead ECGs from N = 54 016 UK Biobank participants (median age, interquartile range, age 58, 50-63 years, 54% female). Cox regression models adjusted for traditional risk factors were used to determine associations with atrial fibrillation (AF), heart failure (HF), myocardial infarction (MI), stroke, life-threatening ventricular arrhythmias (LTVAs), and mortality over a period of 11.5 (11.4-11.7) years. The strongest associations were found between PVCs (prevalence 2.2%) and HF (hazard ratio, HR, 95% confidence interval = 2.09, 1.58-2.78) and between PACs (prevalence 1.9%) and AF (HR = 2.52, 2.11-3.01), with shorter prematurity further increasing risk. Premature ventricular contractions and PACs were also associated with LTVA (P < 0.05). Associations with MI, stroke, and mortality were significant only in unadjusted models. In a separate UK Biobank sub-study sample [UKB-2, N = 29,324, age 64, 58-60 years, 54% female, follow-up 3.5 (2.6-4.8) years] used for independent validation, after adjusting for risk factors, PACs were associated with AF (HR = 1.80, 1.12-2.89) and PVCs with HF (HR = 2.32, 1.28-4.22).

Conclusion

In middle-aged individuals without CVD, premature contractions identified in 15 s single-lead ECGs are strongly associated with an increased risk of AF and HF. These data warrant further investigation to assess the role of wearable ECGs for early cardiovascular risk stratification.

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.

Premature atrial contractions: A predictor of atrial fibrillation and a relevant marker of atrial cardiomyopathy

An increased burden of premature atrial contractions (PACs) has long been considered a benign phenomenon. However, strong evidence of their involvement in the occurrence of atrial fibrillation (AF), ischemic stroke, and excess mortality suggests the need for management. The central question to be resolved is whether increased ectopic atrial rhythm is only a predictor of AF or whether it is a marker of atrial cardiomyopathy and therefore of ischemic stroke. After reviewing the pathophysiology of PACs and its impact on patient prognosis, this mini-review proposes to 1) detail the physiological and clinical elements linking PACs and AF, 2) present the evidence in favor of supraventricular ectopic activity as a marker of cardiomyopathy, and 3) outline the current limitations of this concept and the potential future clinical implications.

Frequent premature atrial contractions as a signalling marker of atrial cardiomyopathy, incident atrial fibrillation and stroke

Premature atrial contractions are a common cardiac phenomenon. Although previously considered a benign electrocardiographic finding, they have now been associated with a higher risk of incident atrial fibrillation and other adverse outcomes such as stroke and all-cause mortality. Since premature atrial contractions can be associated with these adverse clinical outcomes independently of atrial fibrillation occurrence, different explanations have being proposed. The concept of atrial cardiomyopathy, where atrial fibrillation would be an epiphenomenon outside the causal pathway between premature atrial contractions and stroke has received traction recently. This concept suggests that structural, functional and biochemical changes in the atria lead to arrhythmia occurrence and thromboembolic events. Some consensus about diagnosis and treatment of this condition have been published, but this is based on scarce evidence, highlighting the need for a clear definition of excessive premature atrial contractions and for prospective studies regarding antiarrhythmic therapies, anticoagulation or molecular targets in this group of patients.

Testes Ergométricos em Pacientes com Anemia Falciforme: Segurança, Viabilidade e Possíveis Implicações no Prognóstico

Fundamento

Pacientes com anemia falciforme (AF) têm risco aumentado de complicações cardiovasculares. O teste ergométrico é usado como marcador de prognóstico em uma série de doenças cardiovasculares. Entretanto, há uma escassez de evidências sobre exercícios em pacientes com AF, especialmente em relação à sua segurança, viabilidade e possível função prognóstica.

Objetivos

Usamos o teste em esteira máximo para determinar a segurança e a viabilidade do teste ergométrico em pacientes com AF. Além disso, os fatores associados à duração do exercício, bem como o impacto das alterações causadas pelo exercício em resultados clínicos, também foram avaliados.

Métodos

113 pacientes com AF que passaram pelo teste ergométrico e por uma avaliação cardiovascular abrangente incluindo um ecocardiograma e os níveis do peptídeo natriurético do tipo B (BNP). O desfecho de longo prazo foi uma combinação de eventos incluindo morte, crises álgicas graves, síndrome torácica aguda ou internações hospitalares por outras complicações associadas â doença falciforme. A análise de regressão de Cox foi realizada para identificar as variáveis associadas ao resultado. Um p valor <0,05 foi considerado estatisticamente significativo.

Resultados

A média de idade foi de 36 ± 12 anos (intervalo, 18-65 anos), e 62 pacientes eram do sexo feminino (52%). A presença de alterações isquêmicas ao esforço e resposta pressórica anormal ao exercício foram detectadas em 17% e 9 % da´população estudada respectivamente. Dois pacientes apresentaram crise álgica com necessidade de internação hospitalar no período de 48 horas da realização do exame. Fatores associados à duração do exercício foram idade, sexo, velocidade máxima de regurgitação tricúspide (RT), e relação E/e’, após a padronização quanto aos marcadores da gravidade da doença. Durante o período médio de acompanhamento de 10,1 meses (variando de 1,2 a 26), 27 pacientes (23%) apresentaram desfechos clínicos adversos. Preditores independentes de eventos adversos foram a concentração de hemoglobina, velocidade do fluxo transmitral tardio (onda A), e a resposta da PA ao exercício.

Conclusões

A realização de testes ergométricos em pacientes com AF, clinicamente estáveis, é viável. A duração do exercício estava associada à função diastólica e a pressão arterial pulmonar. A resposta anormal da PA foi um preditor independente de eventos adversos.

Detection of focal source and arrhythmogenic substrate from body surface potentials to guide atrial fibrillation ablation

Focal sources (FS) are believed to be important triggers and a perpetuation mechanism for paroxysmal atrial fibrillation (AF). Detecting FS and determining AF sustainability in atrial tissue can help guide ablation targeting. We hypothesized that sustained rotors during FS-driven episodes indicate an arrhythmogenic substrate for sustained AF, and that non-invasive electrical recordings, like electrocardiograms (ECGs) or body surface potential maps (BSPMs), could be used to detect FS and AF sustainability. Computer simulations were performed on five bi-atrial geometries. FS were induced by pacing at cycle lengths of 120-270 ms from 32 atrial sites and four pulmonary veins. Self-sustained reentrant activities were also initiated around the same 32 atrial sites with inexcitable cores of radii of 0, 0.5 and 1 cm. FS fired for two seconds and then AF inducibility was tested by whether activation was sustained for another second. ECGs and BSPMs were simulated. Equivalent atrial sources were extracted using second-order blind source separation, and their cycle length, periodicity and contribution, were used as features for random forest classifiers. Longer rotor duration during FS-driven episodes indicates higher AF inducibility (area under ROC curve = 0.83). Our method had accuracy of 90.6±1.0% and 90.6±0.6% in detecting FS presence, and 93.1±0.6% and 94.2±1.2% in identifying AF sustainability, and 80.0±6.6% and 61.0±5.2% in determining the atrium of the focal site, from BSPMs and ECGs of five atria. The detection of FS presence and AF sustainability were insensitive to vest placement (±9.6%). On pre-operative BSPMs of 52 paroxysmal AF patients, patients classified with initiator-type FS on a single atrium resulted in improved two-to-three-year AF-free likelihoods (p-value < 0.01, logrank tests). Detection of FS and arrhythmogenic substrate can be performed from ECGs and BSPMs, enabling non-invasive mapping towards mechanism-targeted AF treatment, and malignant ectopic beat detection with likely AF progression.

The Beneficial Effects of Beta Blockers on the Long-Term Prognosis of Patients With Premature Atrial Complexes

Aims

Premature atrial complexes (PACs) have been reported to increase the risk of adverse cardiovascular outcomes. Beta blockers at low dosages may help to reduce PAC symptoms, but it is unclear whether they can improve long-term outcomes.

Methods

Patients enrolled from a Holter cohort in a medical referral center were stratified into high-burden (≥100 beats/24 h) and low-burden (<100 beats/24 h) sub-cohorts, and propensity score matching between treatment groups and non-treatment groups was conducted for each sub-cohort.

Results

In the high-burden sub-cohort, after propensity score matching, the treatment group and non-treatment group respectively had 208 and 832 patients. The treatment group had significantly lower mortality rates than the non-treatment group [hazard ratio (HR) = 0.521, 95% confidence interval (CI) = 0.294–0.923, p = 0.025], but there was no difference in new stroke (HR = 0.830, 95% CI = 0.341–2.020, p = 0.681), and new atrial fibrillation (HR = 1.410, 95% CI = 0.867–2.292, p = 0.167) events. In the low-burden sub-cohort, after propensity score matching, there were 614 patients in the treatment group and 1,228 patients in the non-treatment group. Compared to the non-treatment group, up to 40% risk reduction in mortality was found in the treatment group (HR = 0.601, 95% CI = 0.396–0.913, p = 0.017), but no differences in new stroke (HR =0.969, 95% CI = 0.562–1.670, p = 0.910) or atrial fibrillation (HR = 1.074, 95% CI = 0.619–1.863, p = 0.800) were found.

Conclusions

Beta blockers consistently decreased long-term mortality in high-burden and low-burden patients. Interestingly, this effect was not achieved through reduction of new-onset stroke or AF, and further research is warranted.

Excessive supraventricular ectopic activity and risk of incident atrial fibrillation in a consecutive population referred to ambulatory cardiac monitoring

Background

Excessive supraventricular ectopic activity (ESVEA), defined as ≥720 premature atrial contractions (PAC) per day or any runs of ≥20 PACs, has been proposed as a surrogate marker for paroxysmal atrial fibrillation (PAF).

Objective

We aimed to estimate the prognostic impact of ESVEA on the future development of PAF in consecutive patients referred to ambulatory cardiac monitoring.

Methods

The cohort consists of a population with comorbidities referred to 48-hour ambulatory electrocardiogram aged 30–98 (n = 1316) between 2009 and 2011. After exclusion of known or current atrial fibrillation (AF) (n = 527) and patients with pacemakers (n = 7), 782 patients were included, with a median follow-up of 8.1 years. Events of incident AF and death were retrieved from patient records.

Results

Mean age was 58.6 ± 15.5 years and 56.5% were women. A total of 101 patients had ESVEA at baseline (12.9%). During follow-up, 69 (8.9%) developed incidental AF. Twenty-three patients with ESVEA developed AF (23%). Incidence rate of AF in patients with and without ESVEA was 37.1/1000 person-years and 9.1 per 1000 person-years, respectively (P < .001). ESVEA was associated with incident AF after adjustment for potential confounders in Cox regression analysis (hazard ratio [HR]: 2.39; 95% confidence interval [CI]: 1.40–4.09) and in competing risk analysis with death as competing risk (subdistribution HR: 2.35; 95% CI: 1.30–4.17).

Conclusion

ESVEA increases the risk of incident AF substantially in a population referred to ambulatory cardiac monitoring.

Prognostic Implications of Supraventricular Arrhythmias

The aim of this study was to establish the prevalence and prognostic implication of progressive supraventricular arrhythmias from frequent supraventricular ectopic complexes, isolated, in bi- or trigeminy, to supraventricular tachycardias with different characteristics. In the STROKESTOP I mass-screening study for atrial fibrillation (AF) in 75- and 76-year olds in Sweden, participants registered 30-second intermittent ECG twice daily for two weeks. The ECG-recordings from STROKESTOP I were re-evaluated using an automated algorithm to detect individuals with frequent supraventricular ectopic complexes or runs. Detected episodes were manually re-examined to confirm the findings. The primary endpoint was AF as ascertained from the national Swedish Patient register. Exploratory secondary endpoints were stroke and death. Median follow-up was 4.2 (interquartile range [IQR] 3.8-4.4) years. Of the examined 6,100 participants, 85% were free of significant supraventricular arrhythmia. In the 894 participants that had arrhythmia, frequent supraventricular ectopic complexes were the most common arrhythmia, n = 709 (11.6%) and irregular supraventricular tachycardias were more common than regular. Individuals with the most AF similar supraventricular tachycardias, irregular and lacking p-waves (termed micro-AF), n = 97 (1.6%) had the highest risk of developing AF (hazard ratio 4.3; 95% confidence interval [CI] 2.7-6.8). They also had increased risk of death (hazard ratio 2.0; CI 1.1-3.8). In conclusion, progression of atrial arrhythmias from supraventricular ectopic complexes to more AF-like episodes is associated with development of AF. Extended screening for AF should be considered in individuals with frequent supraventricular activity, especially in those with supraventricular tachycardias with AF characteristics.

Higher premature atrial complex burden from the Holter examination predicts poor cardiovascular outcome

Premature atrial complexes (PACs) have been suggested to increase the risk of adverse events. The distribution of PAC burden and its dose–response effects on all-cause mortality and cardiovascular death had not been elucidated clearly. We analyzed 15,893 patients in a medical referral center from July 1st, 2011, to December 31st, 2018. Multivariate regression driven by ln PAC (beats per 24 h plus 1) or quartiles of PAC burden were examined. Older group had higher PAC burden than younger group (p for trend < 0.001), and both genders shared similar PACs distribution. In Cox model, ln PAC remained an independent risk factor for all-cause mortality (hazard ratio (HR) = 1.09 per ln PAC increase, 95% CI = 1.06‒1.12, p < 0.001). PACs were a significant risk factor in cause-specific model (HR = 1.13, 95% CI = 1.05‒1.22, p = 0.001) or sub-distribution model (HR = 1.12, 95% CI = 1.04‒1.21, p = 0.004). In ordinal PAC model, 4th quartile group had significantly higher risk of all-cause mortality than those in 1st quartile group (HR = 1.47, 95% CI = 1.13‒1.94, p = 0.005), but no difference in cardiovascular death were found in competing risk analysis. In subgroup analysis, the risk of high PAC burden was consistently higher than in low-burden group across pre-specified subgroups. In conclusion, PAC burden has a dose response effect on all-cause mortality and cardiovascular death.

Association between P wave polarity in atrial premature complexes and cardiovascular events in a community-dwelling population

OBJECTIVE

To examine the association between polarity of atrial premature complexes (APCs) and stroke.

DESIGN

A prospective study.

SETTING AND PARTICIPANTS

A total of 11 092 participants in the Jichi Medical School cohort study were included after excluding patients with atrial fibrillation. We analysed stroke events in patients with (n=136) and without (n=10 956) APCs. With regard to polarity of APCs, patients were subcategorised into having (1) negative (n=39) or non-negative (n=97) P waves in augmented vector right (aVR), and (2) positive (n=28) or non-positive (n=108) P waves in augmented vector left (aVL).

OUTCOME MEASURES

The primary endpoint was stroke.

RESULTS

Patients with APCs were significantly older than those without APCs (64.1±9.2 vs 55.1±11.6 years, p<0.001). The mean follow-up period was 11.8±2.4 years. Stroke events were observed in patients with (n=13 events) and without (n=411 events) APCs. This difference was significant (log-rank 12.9, p<0.001); however, APCs were not an independent predictor of stroke after adjusting for age, sex, height, body mass index, current drinking, diabetes, systolic blood pressure, prior myocardial infarction, prior stroke and high-density lipoprotein-cholesterol (p=0.15). The incidence of stroke in patients with APCs and non-negative P wave in aVR was significantly higher than in patients without APCs (log-rank 20.1, p<0.001), and non-negative P wave in aVR was revealed to be an independent predictor of stroke (HR 1.84, 95% CI 1.02 to 3.30). The incidence of stroke in patients with APC with non-positive P wave in aVL was also significantly higher than in patients without APC (log-rank 15.3, p<0.001), and non-positive P wave in aVL was an independent predictor of stroke (HR 1.92, 95% CI 1.05 to 3.54).

CONCLUSIONS

The presence of APCs with non-negative P wave in aVR or non-positive P wave in aVL on 12-lead ECG was associated with a higher risk of incident stroke.

Atrial Cardiopathy and Likely Pathogenic Patent Foramen Ovale in Embolic Stroke of Undetermined Source

BACKGROUND

 Atrial cardiopathy and likely pathogenic patent foramen ovale (PFO) are two potential embolic sources in patients with embolic stroke of undetermined source (ESUS). The relationship between these two mechanisms among ESUS patients remains unclear.

METHODS

 Atrial cardiopathy was defined as increased left atrial diameter index (> 23 mm/m²) or left atrial volume index (> 34 mL/m²), or PR prolongation (≥ 200 ms), or presence of supraventricular extrasystoles in the electrocardiograms performed during hospitalization for the index stoke. The presence of PFO was assessed by transthoracic echocardiography with microbubble test or by transesophageal echocardiography. The presence of PFO was considered as likely pathogenic if the Risk of Paradoxical Embolism score was 7 to 10.

RESULTS

 Among 367 ESUS patients with available information about the presence of PFO and the presence of atrial cardiopathy (median age: 61 years, 40.6% women), likely pathogenic PFO was diagnosed in 62 (16.9%) and atrial cardiopathy in 122 (33.2%). Only 4 patients (1.1%) had both likely pathogenic PFO and atrial cardiopathy. The prevalence of atrial cardiopathy was lower in patients with likely pathogenic PFO (6.5%) compared with patients with likely incidental PFO (31.2%) or without PFO (40.6%) (Pearson's chi-square test: 26.08, p < 0.001; adjusted odds ratio [OR]: 0.28, 95% confidence interval [CI]: 0.09-0.86). The prevalence of likely pathogenic PFO was lower in patients with atrial cardiopathy compared with patients without atrial cardiopathy (3.3% vs. 23.7%, respectively [Pearson's chi-square test: 24.13, p < 0.001; adjusted OR: 0.2, 95% CI: 0.02-0.6]).

CONCLUSION

 The presence of atrial cardiopathy is inversely related to the presence of likely pathogenic PFO in patients with ESUS.

Transient atrial mechanical dysfunction assessed in acute phase of embolic stroke of undetermined source

BACKGROUND AND PURPOSE

Paroxysmal atrial fibrillation (PAF) has been suggested as a major cause of embolic stroke of undetermined source (ESUS). Transient atrial mechanical dysfunction (stunning) frequently occurs after conversion of atrial fibrillation to sinus rhythm. The study aim was to determine if reversible atrial mechanical dysfunction in ESUS could help elucidate the mechanism of stroke.

METHODS

Eighty-five consecutive patients with acute ischemic stroke were enrolled according to the following inclusion criteria: [1] ≥55 years old; [2] normal sinus rhythm upon admission; [3] no apparent embolic source; and [4] transthoracic echocardiographic evaluation had been performed in both the early phase (<72 h) and late phase (>7 days) after stroke onset. There were 27 patients in the lacunar or atherothrombotic infarction group (controls), 22 in the PAF group, and 36 in the ESUS group. To determine atrial stunning, transmitral flow velocity profiles (Doppler peak E- [early diastolic] and A- [atrial systolic] waves) were obtained.

RESULTS

In the early phase, an E/A velocity ratio ≥ 1.0 was less common in the control group (1 patient, 3.7%) than in the PAF group (19 patients, 86.4%; p < 0.001) and ESUS group (10 patients, 27.8%; p < 0.05). In the late phase, the E/A ratio decreased to less than 1.0 in six patients (31.6%) who had PAF and in eight patients (80.0%) who had ESUS.

CONCLUSION

Transient atrial mechanical dysfunction could be a helpful finding for elucidating the stroke mechanism in patients with ESUS, and early echocardiographic assessment could improve its detection.

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.

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.

Brief episodes of rapid irregular atrial activity (micro-AF) are a risk marker for atrial fibrillation: a prospective cohort study

Background

Short supraventricular tachycardias with atrial fibrillation (AF) characteristics are associated with an increased risk of developing AF over time. The aim of this study is to determine if presence of very short-lasting episodes of AF-like activity (micro-AF) can also be used as a marker of undiagnosed silent atrial fibrillation.

Methods

In the STROKESTOP II study, a Swedish mass screening study for AF among 75- and 76-year-olds, participants with NT-proBNP ≥125 ng/L performed intermittent ECG recordings 30 s, four times daily for 2 weeks. Participants with micro-AF (sudden onset of irregular tachycardia with episodes of ≥5 consecutive supraventricular beats and total absence of p-waves, lasting less than 30 s) were invited to undergo extended AF screening using continuous event recording for 2 weeks. A control group of individuals without micro-AF was examined using the same ECG modalities.

Results

Out of 3763 participants in STROKESTOP II who had elevated NT-proBNP levels and were free of AF, n = 221 (6%) had micro-AF. The majority of participants with micro-AF (n = 196) accepted further investigation with continuous ECG monitoring which showed presence of AF in 26 of them. In the control group (n = 250), continuous monitoring detected 7 new AF cases. Thus, AF was significantly more common in the micro AF group (13%) compared to the control group (3%), p < 0.001.

Conclusions

Presence of short-lasting episodes of AF-like activity (micro-AF) indicates increased likelihood for undetected AF. Continuous screening therefore seems recommendable if a finding of AF would change clinical management.

Trail registration

ClinicalTrials.gov, identifier: NCT02743416, registered April 19, 2016.

Burden of Premature Atrial Complexes and Risk of Recurrent Stroke and Death in Patients with Mild to Moderate Ischemic Stroke

BACKGROUND

Premature atrial complexes (PACs) meet increased attention as a potential intermediary between sinus rhythm and atrial fibrillation (AF). Patients with even high numbers of PACs do not fulfill current guidelines for oral anticoagulation treatment though an associated stroke risk is suspected.

OBJECTIVE

We aimed to determine whether a high number of PACs or runs of AF less than 30 seconds in 2-day continuous electrocardiogram (ECG) recording was associated with risk of recurrent ischemic stroke/transient ischemic attack (TIA) or death in a large cohort of patients with acute ischemic stroke or TIA and no prior AF.

METHODS

We performed 48 hours continuous ECG recording within 1 week after ischemic stroke/TIA. PACs were reported as mean number of PACs per hour. Patients were followed in Danish Stroke Registry, Danish Civil Registration System, and Danish National Patient Registry. Cox Regression analysis was used to calculate hazard ratios.

RESULTS

We included 1507 patients with TIA (40%) or ischemic stroke (60%), of which 98.7% had mild to moderate strokes. Mean age was 72.9 (7.8) years, 43.4% were females. Follow-up was 2.3 (1.3) years. Hazard ratio for recurrent stroke/TIA or death did not differ between quartiles of PAC burden, nor did any of the 2 components of this composite endpoint. Nonsustained AF less than 30 seconds was not associated with higher risk of recurrent stroke/TIA or death.

CONCLUSIONS

In a large cohort of patients with recent ischemic stroke or TIA, burden of PACs or nonsustained AF less than 30 seconds were not associated to higher risk of recurrent stroke/TIA or death.

Association between excessive premature atrial complexes and cryptogenic stroke: results of a case-control study

OBJECTIVE

Recent anticoagulation trials in all-comer cryptogenic stroke patients have yielded equivocal results, reinvigorating the focus on identifying reproducible markers of an atrial myopathy. We investigated the role of excessive premature atrial complexes (PACs) in ischaemic stroke, including cryptogenic stroke and its association with vascular risk factors.

METHODS AND RESULTS

A case-control study was conducted utilising a multicentre institutional stroke database to compare 461 patients with an ischaemic stroke or transient ischaemic attack (TIA) with a control group consisting of age matched patients without prior history of ischaemic stroke/TIA. All patients underwent 24-hour Holter monitoring during the study period and atrial fibrillation was excluded. An excessive PAC burden, defined as ≥200 PACs/24 hours, was present in 25.6% and 14.7% (p<0.01), of stroke/TIA and control patients, respectively. On multivariate regression, excessive PACs (OR 1.97; 95% CI 1.29 to 3.02; p<0.01), smoking (OR 1.58; 95% CI 1.06 to 2.36; p<0.05) and hypertension (OR 1.53; 95% CI 1.07 to 2.17; p<0.05) were independently associated with ischaemic stroke/TIA. Excessive PACs remained the strongest independent risk factor for the cryptogenic stroke subtype (OR 1.95; 95% CI 1.16 to 3.28; p<0.05). Vascular risk factors that promote atrial remodelling, increasing age (≥75 years, OR 3.64; 95% CI 2.08 to 6.36; p<0.01) and hypertension (OR 1.54; 95% CI 1.01 to 2.34; p<0.05) were independently associated with excessive PACs.

CONCLUSIONS

Excessive PACs are independently associated with cryptogenic stroke and may be a reproducible marker of atrial myopathy. Prospective studies assessing their utility in guiding stroke prevention strategies may be warranted.

Relation of Atrial Premature Complexes During Exercise Stress Testing to the Risk for the Development of Atrial Fibrillation in Patients Undergoing Cardiac Rehabilitation

Atrial fibrillation (AF) is associated with increased morbidity and mortality. We sought to determine whether atrial premature complexes (APCs) detected during a standard exercise stress test (EST) in patients undergoing cardiac rehabilitation (CR) are associated with an increased risk of AF. The present study population comprised 6,523 consecutive patients without prior AF who participated in a CR program in a tertiary medical center in years 2009 to 2016. Multivariate analysis was used to identify the association between APCs during the baseline EST at CR and the risk for the development of AF over a mean follow-up period of 2.5 years. A total of 213 (3.7%) patients had APCs during their EST. Despite being older (mean age 63 ± 13 years old vs 58 ± 13; p <0.001, respectively), no other statistically significant differences were documented. Kaplan-Meier survival analysis showed that the rate of AF development during follow-up was significantly higher in patients with APCs at baseline EST (11%) as compared with those without APCs (5%; log-rank p <0.001 for the overall difference during follow-up). Consistently, multivariate analysis showed that patients with APCs showed >twofold increase risk for AF compared with those without APCs (hazard ratio 2.1; 95% confidence interval 1.36 to 3.25; p <0.001). In conclusion, our findings suggest that APCs detected during EST in patients participating in the CR program independently predict AF and can be used to improve risk stratification in this population.

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.

Relation of premature atrial complexes with stroke and death: Systematic review and meta-analysis

Frequent premature atrial complexes (PACs) are universal in the general population; however, their clinical significance is unclear. We hypothesize that frequent PACs are associated with increased risk of stroke and death. The PubMed (from 1966 to April 2017) and Embase (from 1974 to April 2017) databases were searched for longitudinal studies that reported the relation of PACs with incidence of stroke and death with various etiologies. Study quality was evaluated, and the relative risks (RR) of unfavorable outcomes in subjects with frequent PACs vs those without were calculated. Eleven studies with overall high quality were eligible according to inclusion criteria. The meta-analysis demonstrated that frequent PACs were associated with an increased risk of stroke (unadjusted RR: 2.20, 95% confidence interval [CI]: 1.79-2.70; adjusted RR: 1.41, 95% CI: 1.25-1.60) and death from all causes (unadjusted RR: 2.17, 95% CI: 1.80-2.63; adjusted RR: 1.26, 95% CI: 1.13-1.41), cardiovascular diseases (unadjusted RR: 2.89, 95% CI: 2.20-3.79; adjusted RR: 1.38, 95% CI: 1.24-1.54), and coronary artery disease (unadjusted RR: 2.74, 95% CI: 1.64-4.58; adjusted RR: 1.74, 95% CI: 1.27-2.37). No significant publication bias was detected. The association was robust in sensitivity analysis, subgroup analysis, and pooled analysis of estimates adjusting for confounding factors. Frequent PACs are not benign phenomena; they are associated with higher risk of unfavorable outcomes. Further research on the optimal management of subjects with frequent PACs is urgently required.

Ectopy on a Single 12-Lead ECG, Incident Cardiac Myopathy, and Death in the Community

BACKGROUND

Atrial fibrillation and heart failure are 2 of the most common diseases, yet ready means to identify individuals at risk are lacking. The 12-lead ECG is one of the most accessible tests in medicine. Our objective was to determine whether a premature atrial contraction observed on a standard 12-lead ECG would predict atrial fibrillation and mortality and whether a premature ventricular contraction would predict heart failure and mortality.

METHODS AND RESULTS

We utilized the CHS (Cardiovascular Health) Study, which followed 5577 participants for a median of 12 years, as the primary cohort. The ARIC (Atherosclerosis Risk in Communities Study), the replication cohort, captured data from 15 792 participants over a median of 22 years. In the CHS, multivariable analyses revealed that a baseline 12-lead ECG premature atrial contraction predicted a 60% increased risk of atrial fibrillation (hazard ratio, 1.6; 95% CI, 1.3-2.0; P<0.001) and a premature ventricular contraction predicted a 30% increased risk of heart failure (hazard ratio, 1.3; 95% CI, 1.0-1.6; P=0.021). In the negative control analyses, neither predicted incident myocardial infarction. A premature atrial contraction was associated with a 30% increased risk of death (hazard ratio, 1.3; 95% CI, 1.1-1.5; P=0.008) and a premature ventricular contraction was associated with a 20% increased risk of death (hazard ratio, 1.2; 95% CI, 1.0-1.3; P=0.044). Similarly statistically significant results for each analysis were also observed in ARIC.

CONCLUSIONS

Based on a single standard ECG, a premature atrial contraction predicted incident atrial fibrillation and death and a premature ventricular contraction predicted incident heart failure and death, suggesting that this commonly used test may predict future disease.

Population-based values and abnormalities of the electrocardiogram in the general Dutch population: The LifeLines Cohort Study

BACKGROUND

Our aim is to present average values and prevalence of electrocardiographic (ECG) abnormalities among the general Dutch population in the LifeLines Cohort.

HYPOTHESIS

The ECG values previously studied in the Caucasian population of smaller cohorts will be confirmed with ECG data from LifeLines.

METHODS

ECG data of 152 180 individuals age 18 to 93 years were available. Individuals with cardiovascular risk factors were excluded to analyze the healthy population. Average values of the ECG for the healthy population were presented as means with 95% and 99% confidence intervals and as medians with first and 99th percentiles.

RESULTS

Median heart rate was highest in the youngest and oldest individuals of the healthy population. Median duration of P wave, PQ interval, and QRS duration were longer in males compared with females. In contrast, median QT interval corrected for heart rate was higher in females. In general, the above-mentioned parameters increased with age. The prevalences of ECG abnormalities adjusted for the Dutch population were 0.9% for atrial fibrillation or flutter, 1.4% for premature atrial complexes, 0.5% for myocardial infarction, 2.1% for ventricular premature complexes, 1.0% for left ventricular hypertrophy, 8.1% for P-R interval >200 ms, and 0.8% for bundle branch block.

CONCLUSIONS

Our study provides an overview of average values and ECG abnormalities and confirms data of previous smaller studies. In addition, we evaluate the age- and sex-dependent normal limits of the P wave and QRS duration and confirm in detail the frontal plane QRS-T angle on the ECG.

Premature atrial complexes in an ischemic stroke population and risk of recurrent stroke: a systematic review

INTRODUCTION

Premature atrial complexes (PACs) have been proposed as a possible mediator between normal sinus rhythm and atrial fibrillation (AF). The aim of this study was to summarize the available knowledge of association between PACs and recurrent stroke or transient ischemic attack (TIA) in ischemic stroke patients. Areas covered: In this systematic review, we investigated the risk of recurrent events in patients who experienced ischemic stroke or TIA. Occurrence of PACs in electrocardiographic monitoring after index stroke/TIA was required. We identified and included three observational cohort studies, investigating in total 1005 patients. The studies reported that a significant burden of PACs occurred in a high proportion of stroke and TIA patients. More PACs were independently associated with an increased risk of recurrent stroke or TIA or the composite of recurrent stroke/TIA or death. Definition of PACs cut-off as well as patient characteristics differed between groups. Expert Commentary: This review supports an association between higher burden of PACs and recurrent stroke, and stresses the need for studies on PACs in stroke patients. A special awareness of stroke patients with a high PACs load is recommendable particularly for assessing the intensity and duration toward AF progression, and possible future treatment recommendations.

Mild Hypokalemia and Supraventricular Ectopy Increases the Risk of Stroke in Community-Dwelling Subjects

BACKGROUND AND PURPOSE

Stroke is independently associated with the common conditions of hypokalemia and supraventricular ectopy, and we hypothesize that the combination of excessive supraventricular ectopic activity and hypokalemia has a synergistic impact on the prognosis in terms of stroke in the general population.

METHODS

Subjects (55-75 years old) from the Copenhagen Holter Study cohort (N=671) with no history of atrial fibrillation or stroke were studied-including baseline values of potassium and ambulatory 48-hour Holter monitoring. Excessive supraventricular ectopic activity is defined as ≥30 premature atrial complexes per hour or any episodes of runs of ≥20. Hypokalemia was defined as plasma-potassium ≤3.6 mmol/L. The primary end point was ischemic stroke. Cox models were used.

RESULTS

Hypokalemia was mild (mean, 3.4 mmol/L; range, 2.7-3.6). Hypokalemic subjects were older (67.0±6.94 versus 64.0±6.66 years; P<0.0001) and more hypertensive (165.1±26.1 versus 154.6±23.5 mm Hg; P<0.0001). Median follow-up time was 14.4 years (Q1-Q3, 9.4-14.7 years). The incidence of stroke was significantly higher in the hypokalemic group (hazard ratio, 1.84; 95% confidence interval, 1.04-3.28) after covariate adjustments, as well as in a competing risk analysis with death (hazard ratio, 1.51; 95% confidence interval, 1.12-2.04). Excessive supraventricular ectopic activity was also associated with stroke (hazard ratio, 2.23; 95% confidence interval, 1.33-3.76). The combination of hypokalemia and excessive supraventricular ectopic activity increased the risk of events synergistically. Stroke rate was 93 per 1000 patient-year (P<0.0001) in this group (n=17) compared with 6.9 (n=480); 11 (n=81), and 13 (n=93) per 1000 patient-year in the groups without the combination.

CONCLUSIONS

The combination of hypokalemia and excessive supraventricular ectopy carries a poor prognosis in terms of stroke.

Prognostic Significance of Premature Atrial Complexes Burden in Prediction of Long-Term Outcome

Background

The prognostic significance of premature atrial complex (PAC) burden is not fully elucidated. We aimed to investigate the relationship between the burden of PACs and long-term outcome.

Methods and Results

We investigated the clinical characteristics of 5371 consecutive patients without atrial fibrillation (AF) or a permanent pacemaker (PPM) at baseline who underwent 24-hour electrocardiography monitoring between January 1, 2002, and December 31, 2004. Clinical event data were retrieved from the Bureau of National Health Insurance of Taiwan. During a mean follow-up duration of 10±1 years, there were 1209 deaths, 1166 cardiovascular-related hospitalizations, 3104 hospitalizations for any reason, 418 cases of new-onset AF, and 132 PPM implantations. The optimal cut-off of PAC burden for predicting mortality was 76 beats per day, with a sensitivity of 63.1% and a specificity of 63.5%. In multivariate analysis, a PAC burden >76 beats per day was an independent predictor of mortality (hazard ratio: 1.384, 95% CI: 1.230 to 1.558), cardiovascular hospitalization (hazard ratio: 1.284, 95% CI: 1.137 to 1.451), new-onset AF (hazard ratio: 1.757, 95% CI: 1.427 to 2.163), and PPM implantation (hazard ratio: 2.821, 95% CI: 1.898 to 4.192). Patients with frequent PAC had increased risk of mortality attributable to myocardial infarction, heart failure, and sudden cardiac death. Frequent PACs increased risk of PPM implantation owing to sick sinus syndrome, high-degree atrioventricular block, and/or AF.

Conclusions

The burden of PACs is independently associated with mortality, cardiovascular hospitalization, new-onset AF, and PPM implantation in the long term.

Successful ablation of frequent atrial premature beats from non-coronary aortic cusp with remote magnetic navigation

A 59-year-old female with structurally normal heart was admitted to our hospital for treatment of highly symptomatic, drug refractory atrial premature beats (APB). ECG revealed atrial parasystolic trigeminy. The arrhythmogenic focus was mapped and ablated using magnetic remote navigation and 3D electroanatomical mapping system. To our knowledge, this is the first report on successful ablation of frequent APBs in the non-coronary aortic cusp.

Atrial Remodeling Following Catheter-Based Renal Denervation Occurs in a Blood Pressure- and Heart Rate-Independent Manner

OBJECTIVES

This study sought to investigate left atrial (LA) remodeling in relation to blood pressure (BP) and heart rate (HR) after renal sympathetic denervation (RDN).

BACKGROUND

In addition to reducing BP and HR in certain patients with hypertension, RDN can decrease left ventricular (LV) mass and ameliorate LV diastolic dysfunction.

METHODS

Before and 6 months after RDN, BP, HR, LV mass, left atrial volume index (LAVI), diastolic function (echocardiography), and premature atrial contractions (PAC) (Holter electrocardiogram) were assessed in 66 patients with resistant hypertension.

RESULTS

RDN reduced office BP by 21.6 ± 3.0/10.1 ± 2.0 mm Hg (p < 0.001), and HR by 8.0 ± 1.3 beats/min (p < 0.001). At baseline, LA size correlated with LV mass, diastolic function, and pro-brain natriuretic peptide, but not with BP or HR. Six months after RDN, LAVI was reduced by 4.0 ± 0.7 ml/kg/m(2) (p < 0.001). LA size decrease was stronger when LAVI at baseline was higher. In contrast, the decrease in LAVI was not dependent on LV mass or diastolic function (E/E' or E/A) at baseline. Furthermore, LAVI decreased without relation to decrease in systolic BP or HR. Additionally, occurrence of PAC (median of >153 PAC/24 h) was reduced (to 68 PAC/24 h) by RDN, independently of changes in LA size.

CONCLUSIONS

In patients with resistant hypertension, LA volume and occurrence of PAC decreased 6 months after RDN. This decrease was independent of BP and HR at baseline or the reduction in BP and HR reached by renal denervation. These data suggest that there is a direct, partly BP-independent effect of RDN on cardiac remodeling and occurrence of premature atrial contractions.