Cardiac arrhythmias and stroke: increased risk in men with high frequency of atrial ectopic beats

Arterial Stiffness and Markers of Atrial Myopathy

BACKGROUND

Arterial stiffness, measured using carotid-femoral pulse wave velocity (c-f PWV) and heart rate-corrected augmentation index (Aix75), is associated with cardiovascular disease, and in some studies incident atrial fibrillation (AF). In this cross-sectional study, we aimed to investigate whether arterial stiffness is associated with markers of atrial myopathy, which refers to structural and electrical changes in the atria that indicate increased AF risk.

METHODS

We included 1050 participants (age 57 ± 4.3 years, 47% males) from the population-based Swedish CArdioPulmonary bioImage Study with c-f PWV and Aix75 data. A random subsample (n = 331) underwent echocardiography. The association between arterial stiffness and atrial myopathy markers was studied using multivariable-adjusted negative binomial regression models for premature atrial complexes (PACs) on 24 h ECG, linear regression for P-wave duration and left atrial volume index (LAVi), and logistic regression models for abnormal P-wave terminal force in V1 (PWTFV1) and P-wave axis.

RESULTS

Arterial stiffness was associated with fewer PACs: incidence rate ratio (IRR) 0.45 (95% CI: 0.31 to 0.65, p < 0.001) per 1 m/s increase in c-f PWV and IRR 0.66 (95% CI: 0.49 to 0.89, p = 0.01) per % increase in Aix75. There was no association between arterial stiffness and P-wave indices, OR 1.09 (95% CI: 0.85 to 1.40), p = 0.50 for abnormal PWTFV1, and β -0.003 (-0.10 to 0.09), p = 0.95 for P-wave duration, both per 1 m/s increase in c-f PWV.

CONCLUSIONS

Arterial stiffness, measured as either c-f PWV or Aix75, was associated with fewer PACs, whereas no association was found with P-wave indices. The association between arterial stiffness and atrial myopathy is complex and merits further study.

Risk of death and thrombosis in patients admitted to the emergency department with supraventricular tachycardias

BACKGROUND

Few data are available on the clinical course of patients with supraventricular tachycardia (SVT).

OBJECTIVE

The purpose of this study was to assess the 1-year risk of adverse events in patients with SVT.

METHODS

This was a retrospective observational study conducted within TriNetX. On the basis of the International Classification of Diseases, Tenth Revision, Clinical Modification codes recorded at the emergency department admission, patients not taking oral anticoagulation were categorized into SVT, atrial fibrillation (AF), atrial flutter, or control (CTRL) groups. The primary outcome was the 1-year risk of a composite of all-cause death or thromboembolism. Cox regression analysis was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) after 1:1 propensity score matching. Sensitivity analyses were performed in clinically relevant subgroups. Incident AF and new oral anticoagulation prescriptions were reported during the study period.

RESULTS

We identified 23,524 patients with SVT (mean age 54.6±19.3 years; 14,000 [59.5%] women), 5413 with atrial flutter (66.9±15.7 years; 1907 [35.2%] women), 157,715 with AF (72.5±14.0 years, 68,813 [43.6%] women), and 150,807 CTRLs (43.0±17.4 years; 88,540 [58.7%] women). After propensity score matching, the risk of composite outcome in patients with SVT was higher than that in CTRLs (HR 2.89; 95% CI 2.65-3.17) but lower than that in patients with atrial flutter (HR 0.87; 95% CI 0.79-0.97) and those with AF (HR 0.69; 95% CI 0.65-0.73). The risk of adverse events in patients with SVT was more pronounced during the first 30 days in males, those aged ≥65 years, or those with multimorbidity. Patients with SVT had an increased risk of incident AF than did CTRLs.

CONCLUSION

The increased risk of adverse events in patients with SVT appears to be most pronounced in the short term and partly associated with the increased likelihood of incident AF.

Impact of Paroxysmal Atrial Tachycardia on Thromboembolic Events and Major Adverse Cardiovascular Events: A Single-Center Retrospective Study

Objective

Atrial fibrillation (AF) is known to increase the risk of thromboembolic events and major adverse cardiovascular events (MACE). The impact of paroxysmal atrial tachycardia (PAT) on these risks remains unclear.

Methods

This retrospective cohort study was conducted involving 889 patients diagnosed with PAT and 1106 control patients without PAT, all of whom underwent their initial 24-hour ECG monitoring between 2015 to 2020. Kaplan-Meier survival analysis and Cox regression analysis were used to evaluate the association between PAT and the study endpoints, including thromboembolic events and MACE.

Results

Over a mean follow-up period of 50.3 months, the incidence of thromboembolic events and MACE was significantly higher in the PAT group compared to the control group (6.5% vs 1.7% and 19.1% vs 9.9%, respectively). After adjusting for common risk factors and baseline imbalances, the PAT group exhibited a significantly elevated risk of thromboembolic events (hazard ratio [HR] 3.782, 95% confidence interval [CI] 2.212-6.467; P <0.001) and MACE (HR 1.795, 95% CI 1.398-2.305; P <0.001). However, the frequency of PAT episodes, heart rate, and maximum heart rate were not significantly associated with these outcomes. Within the PAT group, a history of stroke, transient ischemic attack, and chronic renal failure were identified as independent risk factors for thromboembolic events, while hypertension, coronary heart disease, heart failure, and chronic renal failure were independently associated with MACE.

Conclusion

PAT, as detected by 24-hour dynamic ECG, is associated with an increased risk of thromboembolic events and MACE.

Comparison of continuous 24-hour and 14-day ECG monitoring for the detection of cardiac arrhythmias in patients with ischemic stroke or syncope

BACKGROUND

Previous studies show that using 12-lead electrocardiogram (ECG) or 24-h ECG monitor for the detection of cardiac arrhythmia events in patients with stroke or syncope is ineffective.

HYPOTHESIS

The 14-day continuous ECG patch has higher detection rates of arrhythmias compared with conventional 24-h ECG monitoring in patients with ischemic stroke or syncope.

METHODS

This cross-sectional study of patients with newly diagnosed ischemic stroke or syncope received a 24-h ECG monitoring and 14-day continuous cardiac monitoring patch and the arrhythmia events were measured.

RESULTS

This study enrolled 83 patients with ischemic stroke or syncope. The detection rate of composite cardiac arrhythmias was significantly higher for the 14-day ECG patch than 24-h Holter monitor (69.9% vs. 21.7%, p = .006). In patients with ischemic stroke, the detection rates of cardiac arrhythmias were 63.4% for supraventricular tachycardia (SVT), 7% for ventricular tachycardia (VT), 5.6% for atrial fibrillation (AF), 4.2% for atrioventricular block (AVB), and 1.4% for pause by 14-day ECG patch, respectively. The significant difference in arrhythmic detection rates were found for SVT (45.8%), AF (6%), pause (1.2%), AVB (2.4%), and VT (9.6%) by 14-day ECG patch but not by 24-h Holter monitor in patients with ischemic stroke or syncope.

CONCLUSIONS

A 14-day ECG patch can be used on patients with ischemic stroke or syncope for the early detection of AF or other cardiac arrhythmia events. The patch can be helpful for physicians in planning medical or mechanical interventions of patients with ischemic stroke and occult AF.

Markers of Atrial Myopathy in the General Population: Prevalence, Predictors, and Inter-Relations

BACKGROUND

Atrial myopathy refers to structural and functional cardiac abnormalities associated with atrial fibrillation and stroke, but appropriate diagnostic criteria are lacking.

OBJECTIVES

This study aimed to assess prevalence, clinical correlates, and overlap between potential atrial myopathy markers.

METHODS

The population-based SCAPIS (Swedish CArdioPulmonary bioImage Study) prospectively included 6,013 subjects without atrial fibrillation with 24-hour electrocardiograms. Resting electrocardiograms measuring P-wave indices were collected at 1 screening site (n = 1,201), and a random sample (n = 385) had echocardiographic left atrial volume index (LAVi). Atrial myopathy markers were defined as ≥500 premature atrial complexes/24 h, LAVi ≥34 mL/m2, P-wave duration >120 milliseconds, or P-wave terminal force in V1 >4,000 ms·s. Clinical correlates included age, sex, body mass index, height, smoking, physical activity, coronary artery disease, diabetes, systolic blood pressure, antihypertensive medication, and low education.

RESULTS

Atrial myopathy was common; 42% of the sample with all diagnostic modalities available had ≥1 atrial myopathy marker, but only 9% had 2 and 0.3% had ≥3. Only P-wave duration and LAVi were correlated (ρ = 0.10; P = 0.04). Clinical correlates of premature atrial complexes, P-wave indices, and LAVi differed; current smoking (34% increase; P < 0.001), systolic blood pressure (4%/mm Hg increase; P = 0.01), diabetes (35% increase; P = 0.001), and coronary artery disease (71% increase; P = 0.003) were associated with premature atrial complexes, physical activity ≥2 h/wk was associated with increased LAVi (β-coefficient = 3.1; P < 0.0001) and body mass index was associated with P-wave duration (β-coefficient = 0.4/kg/m2; P < 0.0001).

CONCLUSIONS

In the general population, indirect markers of atrial myopathy are common but only weakly correlated, and their risk factor patterns are different. More studies are needed to accurately identify individuals with atrial myopathy with diagnostic methods.

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.

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.

Automatic detection of arrhythmias from an ECG signal using an auto-encoder and SVM classifier

Millions of people around the world are affected by arrhythmias, which are abnormal activities of the functioning of the heart. Most arrhythmias are harmful to the heart and can suddenly become life-threatening. The electrocardiogram (ECG) is an important non-invasive tool in cardiology for the diagnosis of arrhythmias. This work proposes a computer-aided diagnosis (CAD) system to automatically classify different types of arrhythmias from ECG signals. First, the auto-encoder convolutional network (ACN) model is used, which is based on a one-dimensional convolutional neural network (1D-CNN) that automatically learns the best features from the raw ECG signals. After that, the support vector machine (SVM) classifier is applied to the features learned by the ACN model to improve the detection of arrhythmic beats. This classifier detects four different types of arrhythmias, namely the left bundle branch block (LBBB), right bundle branch block (RBBB), paced beat (PB), and premature ventricular contractions (PVC), along with the normal sinus rhythms (NSR). Among these arrhythmias, PVC is particularly a dangerous type of heartbeat in ECG signals. The performance of the model is measured in terms of accuracy, sensitivity, and precision using a tenfold cross-validation strategy on the MIT-BIH arrhythmia database. The obtained overall accuracy of the SVM classifier was 98.84%. The result of this model is portrayed as a better performance than in other literary works. Thus, this approach may also help in further clinical studies of cardiac cases.

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.

Diagnostic Accuracy of Smartwatches for the Detection of Cardiac Arrhythmia: Systematic Review and Meta-analysis

Background

Significant morbidity, mortality, and financial burden are associated with cardiac rhythm abnormalities. Conventional investigative tools are often unsuccessful in detecting cardiac arrhythmias because of their episodic nature. Smartwatches have gained popularity in recent years as a health tool for the detection of cardiac rhythms.

Objective

This study aims to systematically review and meta-analyze the diagnostic accuracy of smartwatches in the detection of cardiac arrhythmias.

Methods

A systematic literature search of the Embase, MEDLINE, and Cochrane Library databases was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify studies reporting the use of a smartwatch for the detection of cardiac arrhythmia. Summary estimates of sensitivity, specificity, and area under the curve were attempted using a bivariate model for the diagnostic meta-analysis. Studies were examined for quality using the Quality Assessment of Diagnostic Accuracy Studies 2 tool.

Results

A total of 18 studies examining atrial fibrillation detection, bradyarrhythmias and tachyarrhythmias, and premature contractions were analyzed, measuring diagnostic accuracy in 424,371 subjects in total. The signals analyzed by smartwatches were based on photoplethysmography. The overall sensitivity, specificity, and accuracy of smartwatches for detecting cardiac arrhythmias were 100% (95% CI 0.99-1.00), 95% (95% CI 0.93-0.97), and 97% (95% CI 0.96-0.99), respectively. The pooled positive predictive value and negative predictive value for detecting cardiac arrhythmias were 85% (95% CI 0.79-0.90) and 100% (95% CI 1.0-1.0), respectively.

Conclusions

This review demonstrates the evolving field of digital disease detection. The current diagnostic accuracy of smartwatch technology for the detection of cardiac arrhythmias is high. Although the innovative drive of digital devices in health care will continue to gain momentum toward screening, the process of accurate evidence accrual and regulatory standards ready to accept their introduction is strongly needed.

Trial Registration

PROSPERO International Prospective Register of Systematic Reviews CRD42020213237; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=213237.

Life's Simple 7 cardiovascular health score and premature atrial contractions: The atherosclerosis risk in communities (ARIC) study

BACKGROUND

Premature atrial contractions (PACs) are associated with increased risk of atrial fibrillation (AF) and ischemic stroke. Although lifestyle and risk factor modification reduces AF incidence, their relationship to PACs frequency is unclear. We assessed the association of Life's Simple 7 (LS7) and individual LS7 factors in midlife with PACs frequency in late life in the Atherosclerosis Risk in Communities (ARIC) Study.

METHODS

We followed 1924 participants from ARIC clinic Visit 3 (1993--95) to Visit 6 (2016-17) when a 2-week continuous heart rhythm monitor (Zio®XT Patch) was applied. LS7 factors were assessed at Visit 3 and a composite score was calculated. PACs frequency was categorized as minimal (<0.1%), occasional (≥0.1%-5%) and frequent (>5%). Logistic regression was used to evaluate the association of LS7 score and individual factors with PACs frequency.

RESULTS

Each 1-point LS7 score increase was associated with lower odds of frequent PACs vs. no PACs (OR [95% CI]: 0.87 [0.78, 0.98]) and frequent PACs vs. occasional PACs (OR [95% CI]: 0.88 [0.79, 0.98]). Of the individual LS7 factors, compared with ideal physical activity, poor physical activity was associated with 81% higher odds of frequent PACs vs. no PACs. Compared with ideal BMI, poor BMI was associated with 41% higher odds of occasional PACs vs. no PACs.

CONCLUSION

Lifestyle risk factors, particularly physical activity and BMI, are associated with higher odds of PACs frequency. More research is needed to determine whether modifying these risk factors in midlife would prevent frequent PACs, and thereby prevent AF and stroke in older age.

Atrial fibrillation is a marker of increased mortality risk in nonischemic heart failure-Results from the DANISH trial

BACKGROUND

Atrial fibrillation (AF) in heart failure (HF) patients has been associated with a worse outcome. Similarly, excessive supraventricular ectopic activity (ESVEA) has been linked to development of AF, stroke, and death. This study aimed to investigate AF and ESVEA's association with outcomes and effect of prophylactic implantable cardioverter defibrillator (ICD) implantation in nonischemic HF patients.

METHODS

A total of 850 patients with nonischemic HF, left ventricle ejection fraction ≤35%, and elevated N-terminal pro-brain natriuretic peptides underwent 24 hours Holter recording. The presence of AF (≥30 seconds) and ESVEA (≥30 supraventricular ectopic complexes (SVEC) per hour or run of SVEC ≥20 beats) were registered. Outcomes were all-cause mortality, cardiovascular death (CVD), and sudden cardiac death (SCD).

RESULTS

AF was identified in 188 patients (22%) and ESVEA in 84 patients (10%). After 4 years and 11 months of follow-up, a total of 193 patients (23%) had died. AF was associated with all-cause mortality (hazard ratio [HR] 1.44; confidence interval [CI] 1.04-1.99; P = .03) and CVD (HR 1.59; CI 1.07-2.36; P = .02). ESVEA was associated with all-cause mortality (HR 1.73; CI 1.16-2.57; P = .0073) and CVD (HR 1.76; CI 1.06-2.92; P = .03). Neither AF nor ESVEA was associated with SCD. ICD implantation was not associated with an improved prognosis for neither AF (P value for interaction = .17), nor ESVEA (P value for interaction = .68).

CONCLUSIONS

Both AF and ESVEA were associated with worsened prognosis in nonischemic HF. However, ICD implantation was not associated with an improved prognosis for either group.

Bariatric surgery may provide better protection than uvulopalatopharyngoplasty against major adverse cardiovascular events in obese patients with obstructive sleep apnea

BACKGROUND

The major adverse cardiovascular events (MACE) risk is unclear among Asian obese patients with obstructive sleep apnea (OSA) who undergo bariatric surgery (BS) or uvulopalatopharyngoplasty (UPPP).

OBJECTIVES

We aimed to evaluate differences between Asian obese patients with OSA who underwent BS or UPPP regarding MACE.

SETTING

The Longitudinal Health Insurance Database, a subset of the NHI Research Database (NHIRD) originated from the National Health Insurance (NHI) program in Taiwan, which comprises information from 2 million randomly sampled individuals between 2000 and 2015.

METHODS

Participants aged 18-55 years whose diagnoses corresponded with codes in the International Classification of Diseases, Ninth Revision, Clinical Modification for BS, UPPP, obesity, and OSA were included in this population-based, matched cohort study of Taiwan's insurance claims data gathered between 2000 and 2015. Obese patients with OSA who underwent BS or UPPP were propensity score matched; the study's outcome was MACE.

RESULTS

A total of 1336 patients, comprising 668 in each of the BS and UPPP cohorts, were enrolled. After a mean follow-up period of 8.51 years, 166 patients, comprising 52 in the BS cohort and 114 in the UPPP cohort, experienced MACE. The adjusted hazard ratio (aHR) for MACE was .592 (95% confidence interval [CI] = .324-.789; P < .001). The BS cohort had lower risks of stroke (aHR = .663; 95% CI = .312-.890; P < .001), myocardial infarction (aHR = .116; 95% CI = .052-.135; P < .001), and mortality (aHR = .779; 95% CI = .423-.948; P = .001) than the UPPP cohort.

CONCLUSION

BS may provide greater protection against MACE than UPPP in Asian obese patients with OSA. Additional mechanistic research is needed to clarify differences between BS and UPPP in these patients.

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.

Opioid, gabapentinoid, and nonsteroidal anti-inflammatory medication use and the risks of atrial fibrillation and supraventricular ectopy in the Multi-Ethnic Study of Atherosclerosis

PURPOSE

Opioids, gabapentinoids, and nonsteroidal anti-inflammatory drugs (NSAIDs) may have adverse cardiovascular effects. We evaluated whether these medications were associated with incident clinically detected atrial fibrillation (AF) or monitor-detected supraventricular ectopy (SVE), including premature atrial contractions (PACs) and supraventricular tachycardia (SVT).

METHODS

We used data from the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort study that enrolled 6814 Americans without clinically detected cardiovascular disease in 2000 to 2002. At the 2016 to 2018 examination, 1557 individuals received ambulatory electrocardiographic (ECG) monitoring. Longitudinal analyses investigated time-varying medication exposures at the first five exams (through 2011) in relation to incident clinically detected AF through 2015 using Cox proportional hazards regression models. Cross-sectional analyses investigated medication exposures at 2016 to 2018 examination and the risk of monitor-detected SVE using linear regression models.

RESULTS

The longitudinal cohort included 6652 participants. During 12.4 years of mean follow-up, 982 participants (14.7%) experienced incident clinically detected AF. Use of opioids, gabapentinoids, and NSAIDs were not associated with incident AF. The cross-sectional analysis included 1435 participants with ECG monitoring. Gabapentinoid use was associated with an 84% greater average frequency of PACs/hour (95% CI, 25%-171%) and a 44% greater average number of runs of SVT/day (95% CI, 3%-100%). No associations were found with use of opioids or NSAIDs in cross-sectional analyses.

CONCLUSIONS

In this study, gabapentinoid use was associated with SVE. Given the rapid increase in gabapentinoid use, additional studies are needed to clarify whether these medications cause cardiovascular complications.

Learning curve predictors for minimally invasive mitral valve surgery; how far should the rabbit hole go?

OBJECTIVE

To analyze predictors that influence the learning curve of minimally invasive mitral valve surgery (MIMVS).

METHODS

Patients who underwent MIMVS between March 2010 to March 2015 were retrospectively analyzed. Predictive factors that influence the learning curve were analyzed.

RESULTS

One hundred and five patients were included in the analysis. Cardiopulmonary bypass (CPB) time in minutes was 158.72 ± 40.98 and the aortic cross-clamp (ACC) time in minutes was 114.48 ± 27.29. There were three operative mortalities, one stroke and five >2+ mitral regurgitation. ACC time in minutes was higher in the low logistic Euroscore II (LES) group (LES < 5% = 118.42 ± 27.94) versus (LES ≥ 5 = 88.66 ± 22.26), P < .05 while creatinine clearance in μmol/L was higher in the LES < 5% group (LES < 5% = 84.32 ± 33.7) versus (LES ≥ 5% = 41.66 ± 17.14), (P < .05). One patient from each group required chest tube insertion for pleural effusion P < .05. The cumulative sum analysis (CUSUM) for the first 25 patients had CPB and ACC times that reached the upper limits. Between 25 to 64 patients the curve remained stable while with the introduction of reoperations and complex surgical procedures the CUSUM reached the upper limits.

CONCLUSIONS

The learning curve is affected by many factors but this should not desist surgeons from approaching this technique. The introduction of high-risk patients in clinical practice should be carefully measured based on surgeon experience.

Establishing reference ranges for ambulatory electrocardiography parameters: meta-analysis

Objective

Despite the widespread and increasing use of ambulatory electrocardiography (ECG), there is no consensus on reference ranges for ambulatory electrocardiogram parameters to guide interpretation. We sought to determine population distribution-based reference ranges for parameters measured during ambulatory electrocardiogram in healthy adults, based on existing literature.

Methods

We searched multiple databases from 1950 to 2020. Articles reporting original data from ≥24-hour ambulatory electrocardiogram monitoring in healthy adults were included. Data extraction and synthesis were performed according to Meta-analysis of Observational Studies in Epidemiology guidelines. The prevalence/mean and SD for common parameters (sinus pauses, conduction abnormalities and ectopy) were extracted by age group (18–39, 40–59, 60–79 and 80+ years).

Results

We identified 33 studies involving 6466 patients. Sinus pauses of >3 s were rare (pooled prevalence <1%) across all ages. Supraventricular ectopy of >1000/24 hours increased with age, from 0% (95% CI 0% to 0%) in those aged 18–39 years to 6% (95% CI 0% to 17%) in those aged 60–79 years. Episodes of supraventricular tachycardia increased from 3% (95% CI 1% to 6%) in those aged 18–39 years to 28% (95% CI 9% to 52%) in those aged 60–79 years. Ventricular ectopy of >1000/24 hours also increased with age, from 1% (95% CI 0% to 2%) in those aged 18–39 years to 5% (95% CI 1% to 10%) in those aged 60–79 years. Episodes of non-sustained ventricular tachycardia ranged from 0% (95% CI 0% to 1%) in those aged 18–39 years to 2% (95% CI 0% to 5%) in those aged 60–79 years.

Conclusion

Despite the limitations of existing published data, this meta-analysis provides evidence-based reference ranges for ambulatory electrocardiogram parameters and highlights significant age-dependent differences that should be taken into account during interpretation.

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.

The difference of burden of ectopic beats in different types of atrial fibrillation and the effect of atrial fibrillation type on stroke risk in a prospective cohort of patients with atrial fibrillation (CODE-AF registry)

The relationship between atrial fibrillation (AF) type and stroke risk is still controversial. We investigated the difference of burden of atrial ectopic beats in different types of AF and the effect of the AF type on stroke risk in patients with non-valvular AF. In the prospective, multicenter observational registry with more than about 10,000 AF patients, 8883 non-valvular AF patients (mean age, 67.0 years; 36% were women) with eligible follow-up visits participated. We compared the burden of ectopic beats and stroke risk between patients with paroxysmal AF (n = 5,808) and non-paroxysmal AF (n = 3,075). The patients with a non-paroxysmal type of AF were older, male-predominant and had a higher prevalence of comorbidities and had more anticoagulation and rhythm control treatment than those with paroxysmal AF. In terms of the difference in burden of ectopic beats, patients with non-paroxysmal AF had a higher proportion of atrial premature beats (APBs) (paroxysmal vs. non-paroxysmal, median 3% vs. 5%; p = 0.001) in 24 hours Holter monitoring. During a median follow-up period of 16.8 months (Interquartile range [IQR], 11.67-20.52), a total of 82 (0.92%) patients experienced ischemic stroke with incidence rates of 0.50 and 1.09 events per 100 person-year for paroxysmal and non-paroxysmal AF, respectively. The cumulative incidence of stroke events was significantly higher in non-paroxysmal AF than in paroxysmal AF (p < 0.001). The risk of ischemic stroke was higher in non-paroxysmal AF with an adjusted hazard ratio (HR) of 2.08 (95% confidence interval [CI], 1.33-3.25; p = 0.001) than in paroxysmal AF. The type of AF was associated with an increased risk of stroke, along with the difference of burden of ectopic beats (specially in APBs) in different types of AF. These results suggest that the type of AF should be considered in stroke prevention and decision-making for oral anticoagulation in AF patients.

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.

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.

Automated beat-wise arrhythmia diagnosis using modified U-net on extended electrocardiographic recordings with heterogeneous arrhythmia types

Abnormality of the cardiac conduction system can induce arrhythmia - abnormal heart rhythm - that can frequently lead to other cardiac diseases and complications, and are sometimes life-threatening. These conduction system perturbations can manifest as morphological changes on the surface electrocardiographic (ECG) signal. Assessment of these morphological changes can be challenging and time-consuming, as ECG signal features are often low in amplitude and subtle. The main aim of this study is to develop an automated computer aided diagnostic (CAD) system that can expedite the process of arrhythmia diagnosis, as an aid to clinicians to provide appropriate and timely intervention to patients. We propose an autoencoder of ECG signals that can diagnose normal sinus beats, atrial premature beats (APB), premature ventricular contractions (PVC), left bundle branch block (LBBB) and right bundle branch block (RBBB). Apart from the first, the rest are morphological beat-to-beat elements that characterize and constitute complex arrhythmia. The novelty of this work lies in how we modified the U-net model to perform beat-wise analysis on heterogeneously segmented ECGs of variable lengths derived from the MIT-BIH arrhythmia database. The proposed system has demonstrated self-learning ability in generating class activations maps, and these generated maps faithfully reflect the cardiac conditions in each ECG cardiac cycle. It has attained a high classification accuracy of 97.32% in diagnosing cardiac conditions, and 99.3% for R peak detection using a ten-fold cross validation strategy. Our developed model can help physicians to screen ECG accurately, potentially resulting in timely intervention of patients with arrhythmia.

Usefulness of Short-Lasting Episodes of Supraventricular Arrhythmia (Micro-Atrial Fibrillation) as a Risk Factor for Atrial Fibrillation

According to the present European Society of Cardiology's guidelines for atrial fibrillation (AF), the definition of AF contains a 30-second time criterion, based on consensus. The aim of this cohort study is to evaluate whether very short-lasting episodes of AF, micro-AF, are risk factors for developing AF and to compare AF detection between continuous and intermittent ECG recordings applied in parallel. All participants, n = 102, were identified from the STROKESTOP study, a Swedish mass-screening study for AF. Participants were divided into 2 groups depending on results in the STROKESTOP study: a micro-AF group (with abrupt onset episodes of ≥4 consecutive supraventricular beats, irregular rate-to-rate intervals, absence of regular p waves, lasting for <30 seconds), n = 54, and a control group, n = 48. After a follow-up period participants who were clinically free of AF were invited to undergo repeat AF screening during a 2-week period, using continuous ECG recording and 30 seconds intermittent recordings simultaneously. After 2.3years of follow-up, significantly more participants in the micro-AF group had developed AF, 27 of 54 (50%), compared with the control group, 5 of 48 (10%), p < 0.001. Among the 94 participants not already diagnosed with AF who underwent AF-screening, 25 of 25 (100%) AF cases were detected with help of continuous monitoring whereas 10 of 25 (40%) AF cases were found with intermittent ECGs. In conclusion, micro-AF seems to be an important risk factor for the development of AF in an elderly population. The detection of AF was significantly higher using 2 weeks of continuous ECG monitoring compared with intermittent 30-second ECG recordings twice daily for 2 weeks.

Reduction of arrhythmias in primary hyperparathyroidism, by parathyroidectomy, evaluated with 24-h ECG monitoring

OBJECTIVE

Hypercalcemia may induce arrhythmias. There are no data on the prevalence of arrhythmias in primary hyperparathyroidism (PHPT) in daily life. Aim of the study was to investigate both the prevalence of arrhythmias in patients with PHPT compared to controls and the impact of parathyroidectomy, evaluated by 24-h electrocardiogram (ECG) monitoring.

DESIGN

This is a randomized study.

METHODS

Twenty-six postmenopausal women with PHPT and 26 controls were enrolled. PHPT patients were randomized to two groups: 13 underwent parathyroidectomy (Group A) and 13 were followed up conservatively (Group B). After 6 months, patients were studied again. Each patient underwent mineral metabolism biochemical evaluation, bone mineral density measurement, standard ECG and 24-h ECG monitoring.

RESULTS

PHPT patients showed higher calcium and parathyroid hormone compared to controls and a higher prevalence of both supraventricular (SVBPs) and ventricular premature beats (VPBs) during 24-h ECG monitoring. Groups A and B showed no differences in mean baseline biochemical values and ECG parameters. Mean value of QTc in PHPT groups was in the normal range at baseline, but significantly shorter than controls. A negative correlation was found between QTc and ionized calcium levels (r = -0.48, P < 0.05). After parathyroidectomy, Group A had a significant reduction in SVPBs and VPBs compared to baseline and restored normal QTc. Group B showed no significant changes after a 6-month period.

CONCLUSIONS

The increased prevalence of SVPBs and VPBs is significantly reduced by parathyroidectomy, and it is mainly related to the short QTc caused by hypercalcemia.

Automated diagnosis of arrhythmia using combination of CNN and LSTM techniques with variable length heart beats

Arrhythmia is a cardiac conduction disorder characterized by irregular heartbeats. Abnormalities in the conduction system can manifest in the electrocardiographic (ECG) signal. However, it can be challenging and time-consuming to visually assess the ECG signals due to the very low amplitudes. Implementing an automated system in the clinical setting can potentially help expedite diagnosis of arrhythmia, and improve the accuracies. In this paper, we propose an automated system using a combination of convolutional neural network (CNN) and long short-term memory (LSTM) for diagnosis of normal sinus rhythm, left bundle branch block (LBBB), right bundle branch block (RBBB), atrial premature beats (APB) and premature ventricular contraction (PVC) on ECG signals. The novelty of this work is that we used ECG segments of variable length from the MIT-BIT arrhythmia physio bank database. The proposed system demonstrated high classification performance in the handling of variable-length data, achieving an accuracy of 98.10%, sensitivity of 97.50% and specificity of 98.70% using ten-fold cross validation strategy. Our proposed model can aid clinicians to detect common arrhythmias accurately on routine screening ECG.

Association of frequent premature ventricular complex >10% and stroke-like symptoms without a prior diagnosis of stroke or transient ischemic attack

Introduction

Premature ventricular complex (PVCs) detected from long-term ECG recordings have been associated with an increased risk of ischemic stroke. However, there was limited data about the association between high PVCs burdens (>10%) and stroke-like symptoms without a prior diagnosis of stroke or transient ischemic attack in the long-term follow up.

Methods

The Kosin University 24-hours holter monitoring, echocardiography, electrocardiogram (ECG) database were reviewed from 2013 to 2015 to identify patients with frequent PVCs (>10%). We compared the long-term clinical outcomes between the patients with frequent PVCs (>10%) and control group without PVC.

Results

Among 572 patients who underwent 24-hours holter monitoring, finally, 373 consecutive patients (mean age; 59.5 ± 15.8 years, 45.2% male) were enrolled. Among them, 203(54.4%) patients had high PVCs burdens (>10%). There was no difference of the baseline characteristics. In the long term follow-up, PVCs burden was not associated with PVCs -related symptoms (P = 0.210). In univariate analysis, female, non-sustained ventricular tachycardia (VT), sinus QRS duration, PVC coupling interval (CI), post- PVC CI, and late precordial R-wave transition of PVCs were associated with PVCs-related symptoms. In multivariate analysis, non-sustained VT (P = 0.022) and late precordial R-wave transition of PVCs (P = 0.044) were independent risk factors for PVCs-related stroke-like symptoms with frequent idiopathic PVCs > 10%.

Conclusion

High PVCs burdens (>10%) were associated with and stroke-like symptoms without a prior diagnosis of stroke or transient ischemic attack in the long-term follow up, suggesting more intensive medical therapy with close clinical follow-up will be required.

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.

Impact of automated ICA-based denoising of fMRI data in acute stroke patients

Different strategies have been developed using Independent Component Analysis (ICA) to automatically de-noise fMRI data, either focusing on removing only certain components (e.g. motion-ICA-AROMA, Pruim et al., 2015a) or using more complex classifiers to remove multiple types of noise components (e.g. FIX, Salimi-Khorshidi et al., 2014 Griffanti et al., 2014). However, denoising data obtained in an acute setting might prove challenging: the presence of multiple noise sources may not allow focused strategies to clean the data enough and the heterogeneity in the data may be so great to critically undermine complex approaches. The purpose of this study was to explore what automated ICA based approach would better cope with these limitations when cleaning fMRI data obtained from acute stroke patients. The performance of a focused classifier (ICA-AROMA) and a complex classifier (FIX) approaches were compared using data obtained from twenty consecutive acute lacunar stroke patients using metrics determining RSN identification, RSN reproducibility, changes in the BOLD variance, differences in the estimation of functional connectivity and loss of temporal degrees of freedom. The use of generic-trained FIX resulted in misclassification of components and significant loss of signal (< 80%), and was not explored further. Both ICA-AROMA and patient-trained FIX based denoising approaches resulted in significantly improved RSN reproducibility (p < 0.001), localized reduction in BOLD variance consistent with noise removal, and significant changes in functional connectivity (p < 0.001). Patient-trained FIX resulted in higher RSN identifiability (p < 0.001) and wider changes both in the BOLD variance and in functional connectivity compared to ICA-AROMA. The success of ICA-AROMA suggests that by focusing on selected components the full automation can deliver meaningful data for analysis even in population with multiple sources of noise. However, the time invested to train FIX with appropriate patient data proved valuable, particularly in improving the signal-to-noise ratio.

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.

Cardioembolic Stroke

Cardiac embolism accounts for an increasing proportion of ischemic strokes and might multiply several-fold during the next decades. However, research points to several potential strategies to stem this expected rise in cardioembolic stroke. First, although one-third of strokes are of unclear cause, it is increasingly accepted that many of these cryptogenic strokes arise from a distant embolism rather than in situ cerebrovascular disease, leading to the recent formulation of embolic stroke of undetermined source as a distinct target for investigation. Second, recent clinical trials have indicated that embolic stroke of undetermined source may often stem from subclinical atrial fibrillation, which can be diagnosed with prolonged heart rhythm monitoring. Third, emerging evidence indicates that a thrombogenic atrial substrate can lead to atrial thromboembolism even in the absence of atrial fibrillation. Such an atrial cardiomyopathy may explain many cases of embolic stroke of undetermined source, and oral anticoagulant drugs may prove to reduce stroke risk from atrial cardiomyopathy given its parallels to atrial fibrillation. Non-vitamin K antagonist oral anticoagulant drugs have recently expanded therapeutic options for preventing cardioembolic stroke and are currently being tested for stroke prevention in patients with embolic stroke of undetermined source, including specifically those with atrial cardiomyopathy. Fourth, increasing appreciation of thrombogenic atrial substrate and the common coexistence of cardiac and extracardiac stroke risk factors suggest benefits from global vascular risk factor management in addition to anticoagulation. Finally, improved imaging of ventricular thrombus plus the availability of non-vitamin K antagonist oral anticoagulant drugs may lead to better prevention of stroke from acute myocardial infarction and heart failure.

Repeatability of ectopic beats from 48-hr ambulatory electrocardiography: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

The purpose of this study was to characterize the repeatability of ectopic beats, defined by premature atrial contractions (PACs) and premature ventricular contractions (PVCs), on ambulatory electrocardiogram (aECG) monitoring and evaluate the effect of length of aECG monitoring on the repeatability estimates.

METHODS

This analysis includes 95 randomly selected participants from the Atherosclerosis Risk in Communities Study (ARIC; 2011-2013). The participants wore a Holter monitor for two, 48-hr periods separated by a mean of 38 days following an identical, standardized protocol. We divided each 48-hr recording into 3-, 6-, 12-, and 24-hr recording periods and calculated intraclass correlation coefficients (ICCs) for PACs and PVCs and also as a percentage of the corresponding total of recorded beats per hour among these periods.

RESULTS

All participants had ≥1 PAC during the 48-hr recordings, and only two participants had no PVCs. ICCs were >0.83 for all indices and recording lengths ≥12 hrs. ICCs were intermediate for 6-hr recordings (range 0.80-0.83) and lower for 3-hr recordings (range 0.74-0.80). The ratio of the between- to within-participant variation increased with recording length.

CONCLUSION

Repeatability of PACs and PVCs was excellent for recording lengths of 6-24 hr and fair for 3 hr. Repeatability varies over shorter duration recordings within the 48-hr recording period, and thus the present results have implications for detection algorithms for ectopic beats and can facilitate epidemiologic and clinical applications in which knowledge of measurement variability and misclassification are needed.

Frequent Atrial Premature Complexes and Their Association With Risk of Atrial Fibrillation

Identification of precursors of atrial fibrillation (AF) may lead to early detection and prevent associated morbidity and mortality. This study aimed to examine the association between frequent atrial premature complexes (APCs) and incidence of AF. For this retrospective cohort study, we analyzed Holter recordings obtained from 2000 to 2010 of 1,357 veterans free of AF at baseline. All pertinent data in electronic medical records were reviewed to ascertain baseline characteristics. Holter groups with frequent (≥100/day) and infrequent (<100/day) APCs were compared for development of new AF over a median follow-up of 7.5 years. Multivariate Cox regression analyses were performed before and after propensity score matching. Mean age was 64 years with 93% men. Mean body mass index, hemoglobin A1C, low-density lipoprotein, left atrial size, and heart rate were 31.24 kg/m(2), 6.42%, 107.92 mg/dl, 4.26 cm, and 73 beats/min, respectively. AF was noted in 21.8% of patients with frequent APCs compared to 5.6% of those with infrequent APCs. After adjusting for demographics, medication use, co-morbidities, and laboratory and echocardiographic findings, multivariate Cox regression analyses confirmed frequent APCs to be independently associated with higher incidence of AF (hazard ratio [HR] 2.97, 95% confidence interval [CI] 1.85 to 4.80; p <0.001). In propensity-matched groups, this association remained significant (HR 2.87, 95% CI 1.65 to 4.98; p <0.001). Additionally, atrial couplets (≥50/day), atrial bigeminy (≥50/day), frequent runs of ≥3 APCs (≥20 runs/day), and longer runs (≥10 beats/run) were significantly associated with AF (HR 3.11, 3.67, 2.94, and 1.73, respectively, all p <0.05). In conclusion, frequent APCs (≥100/day) are associated with greater risk of AF.

Silent Atrial Fibrillation: Definition, Clarification, and Unanswered Issues

Silent or subclinical asymptomatic atrial fibrillation has currently gained wide interest in the epidemiologic, neurologic and cardiovascular communities. The association of brief episodes of paroxysmal atrial fibrillation or surrogate atrial arrhythmias which predict future clinical adverse events have been established. Nevertheless there exists a confounding array of definitions to indicate its presence without discrete indication of which populations should be examined. Moreover the term "atrial fibrillation burden" (AFB) has emerged from such studies with a plethora of descriptions to prognosticate both arrhythmic and clinical adverse events. This presentation suggests clarification of diagnostic definitions associated with silent atrial fibrillation, and a more precise description of AFB. It examines the populations across the current disease and cardiovascular invasive therapeutic spectrum that lead to both silent atrial fibrillation and AFB. It describes the diagnostic methods of arrhythmia detection utilizing the surface ECG, subcutaneous ECG or intra-cardiac devices and their relationship in seeking meaningful arrhythmic markers of silent atrial fibrillation. Whereas a wide range of clinical risk factors of silent atrial fibrillation have been validated in the literature, there is an ongoing search for those arrhythmic risk factors that precisely identify and prognosticate outcome events in diverse populations at risk of atrial fibrillation and its complications. This presentation identifies this chaos, and focuses attention on the issues to be addressed to facilitate descriptive and comparative scientific studies in the future. It is a call to action specifically to the medical arrhythmic community and its specialty societies (i.e., ISHNE, HRS, EHRA) to begin a quest to unravel the arrhythmic quagmire associated with "silent atrial fibrillation."

Risk of Cerebrovascular Diseases After Uvulopalatopharyngoplasty in Patients With Obstructive Sleep Apnea: A Nationwide Cohort Study

Little was known about the beneficial effects of uvulopalatopharyngoplasty (UPPP) on the outcomes after obstructive sleep apnea (OSA). The aim of this study is to investigate the effects of UPPP on reducing risk of cerebrovascular diseases in patients with OSA.Using Taiwan's National Health Insurance Research Database, we conducted a retrospective cohort study of 10,339 patients with new OSA between January 1, 2004, and December 31, 2009. The incident cerebrovascular disease was identified during the 1-year follow-up period in patients with and without receiving UPPP. The rate ratios (RRs) and 95% confidence intervals (CIs) of cerebrovascular disease associated with receiving UPPP in patients with OSA were calculated in multivariate Poisson regression.The 1-year incidences of cerebrovascular disease for OSA patients with and without UPPP were 1.06% and 5.14%, respectively. Patients with OSA receiving UPPP had lower risk of cerebrovascular disease compared with those without UPPP (RR, 0.45; 95% CI, 0.33-0.61). The decreased risk of cerebrovascular disease following UPPP was observed in both sexes and all age groups. In the stratified analysis of medical conditions, the RR of cerebrovascular disease associated with UPPP for patients with 0, 1, ≥ 2 medical conditions were 0.28 (95% CI 0.12-0.68), 0.39 (95% CI 0.21-0.73), and 0.63 (95% CI 0.43-0.93), respectively.Patients with OSA who received UPPP had lower risk of cerebrovascular disease within 1 year after surgery compared with patients not receiving UPPP. Clinical physicians could have more evidence to persuade patients to receive surgical intervention, especially those who have severe OSA symptoms or do not acquire adequate symptom relief under conservative treatments.

Revisiting Clinical Utility of Chest Radiography and Electrocardiogram to Determine Ischemic Stroke Subtypes: Special Reference on Vascular Pedicle Width and Maximal P-Wave Duration

BACKGROUNDS

It is often difficult to diagnose stroke subtypes at admission, particularly in sinus rhythm cases. Vascular pedicle width (VPW) on chest X-ray (CXR) and maximal P-wave duration (P-max) on electrocardiogram (ECG) are again realized as useful parameters reflecting intravascular volume and atrial conduction status, respectively. We investigated the utility of VPW and P-max as a tool for differentiating ischemic stroke subtypes.

METHODS

We studied 343 acute stroke patients showing sinus rhythm on admission. Dividing the patients into cardioembolic (CE) stroke (n = 57) and non-CE (n = 286) groups, we compared clinical backgrounds including VPW on CXR, and P-max in lead II and premature atrial contraction (PAC) on 12-leads ECG. Then, we investigated the independent factors for CE.

RESULTS

Independent factors associated with CE were VPW (≥59.3 mm) (p < 0.001; odds ratio (OR), 10.12; 95% confidence interval (CI), 4.13-24.8), P-max in lead II (≥120 ms) (p < 0.001; OR, 8.61; 95% CI, 3.96-18.7), PAC (p = 0.002; OR, 7.35; 95% CI, 2.14-25.3) and D-dimer level (≥1.11 µg/ml) (p = 0.016; OR, 2.57; 95% CI, 1.20-5.51).

CONCLUSIONS

VPW, P-max, PAC and D-dimer are useful parameters for diagnosing CE stroke in patients with sinus rhythm at admission.