Although cardiac arrhythmias have been observed and described during and after SARS-CoV-2 infection, rigorous studies designed to untangle the complex relationship between this proinflammatory illness and arrhythmogenesis are limited. Despite a pervasive opinion to the contrary, there is presently no definitive data to establish a causal, viral-specific association between COVID-19 and incident arrhythmia.

Background

Cardiac resynchronization therapy (CRT) has been shown to improve both the functional status and mortality of heart failure patients with left bundle branch block. Multiple recent studies suggest several mechanisms for proarrhythmia associated with CRT device.

Case summary

A 51-year-old male with symptomatic non-ischemic cardiomyopathy and no previous history of ventricular arrhythmias underwent placement of a biventricular cardioverter-defibrillator. The patient developed sustained monomorphic ventricular tachycardia (VT) soon after implantation. The VT recurred despite reprogramming to right ventricular only pacing. The electrical storm resolved only after a subsequent discharge from the defibrillator caused inadvertent dislodgement of the coronary sinus lead. No recurrent VT occurred throughout 10-years follow up after urgent coronary sinus lead revision.

Discussion

We describe the first reported case of mechanically induced electrical storm due to the physical presence of the CS lead in a patient with a new CRT-D device. It is important to recognize mechanical proarrhythmia as a potential mechanism of electrical storm, as it may be intractable to device reprogramming. Urgent coronary sinus lead revision should be considered. Further studies on this mechanism of proarrhythmia are needed.

The American Indian population is known to experience high rates of cardiovascular disease and have a heightened vulnerability to severe outcomes driven by an overall poor health status and lower access to quality health care. Our group has previously published an analysis demonstrating that American Indians have the highest risk of atrial fibrillation (AF), as well as of AF-related stroke, when compared with other races and ethnicities. Despite this, AF in this population has not been extensively studied and additional publications are scarce. Our review article provides an up-to-date summary of the relevant literature addressing the relationship between race, ethnicity, and AF by focusing on American Indians.

Atrial fibrillation (AF) is a major cause of morbidity and mortality globally, and much of this is driven by challenges in its timely diagnosis and treatment. Existing and emerging mobile technologies have been used to successfully identify AF in a variety of clinical and community settings, and while these technologies offer great promise for revolutionizing AF detection and screening, several major barriers may impede their effectiveness. The unclear clinical significance of device-detected AF, potential challenges in integrating patient-generated data into existing healthcare systems and clinical workflows, harm resulting from potential false positives, and identifying the appropriate scope of population-based screening efforts are all potential concerns that warrant further investigation. It is crucial for stakeholders such as healthcare providers, researchers, funding agencies, insurers, and engineers to actively work together in fulfilling the tremendous potential of mobile technologies to improve AF identification and management on a population level.

OBJECTIVES: We sought to investigate the prevalence and predictors of oral anticoagulation prescription among patients with atrial fibrillation (AF) at the lowest risk for thromboembolism, despite contemporary consensus guidelines that do not recommend anticoagulation therapy in this population. BACKGROUND: In young and healthy AF patients without significant thromboembolic risk factors, anticoagulant treatment carries bleeding risks that outweigh stroke prevention benefit. METHODS: Within a large contemporary registry of cardiology outpatients, we identified low-risk patients with AF meeting criteria for a contemporary consensus guideline class III indication against use of anticoagulation (age < 60 years, CHADS2 Score=0, and no structural heart disease) between 2008–2012, and a second cohort with the same criteria and a CHA2DS2-VASc Score of 0. Using hierarchical modified Poisson regression models adjusted for patient characteristics, we examined predictors of oral anticoagulation treatment in these low thromboembolic risk AF patients. RESULTS: Oral anticoagulation was prescribed in a total of 2,561 of 10,995 (23.2%) AF patients with a CHADS2 score of 0 and 1,787 of 6,730 (26.6%) AF patients with a CHA2DS2-VASc score of 0. In multivariable analysis, older age (RR 1.48 per 10 years; 95% CI, 1.41–1.56; p<0.0001), male sex (RR 1.34; 95% CI, 1.22–1.46; p<0.0001), higher body mass index (RR 1.18 per 5 kg/m2; 95% CI, 1.14–1.22; p<0.0001), and Medicare insurance (reference: private insurance; RR,1.32; 95% CI, 1.17–1.49; overall p<0.0001) were associated with a higher likelihood of oral anticoagulant prescription, whereas treatment in Southern states (reference: Northeast; RR 0.69; 95% CI, 0.49–0.98;overall p=0.1187) was associated with a lower likelihood of oral anticoagulant prescription. CONCLUSIONS: In a large, real-world population of AF patients with the lowest thrombotic risk, approximately 1 in 4 were treated with oral anticoagulation against contemporary guideline recommendations.

AIMS:Premature atrial contractions (PACs) are known to trigger and predict atrial fibrillation (AF). We sought to identify the determinants of PACs and the degree to which PACs mediate the effects of established risk factors for AF. METHODS AND RESULTS:Predictors of baseline PAC frequency were examined using a Holter Study among 1392 participants in the Cardiovascular Health Study, a community-based cohort of individuals aged ≥65 years. Participants were then followed for their first diagnosis of AF. Independent predictors of PACs were identified, and the extent to which PACs might mediate the relationship between those predictors and AF was determined. The median hourly frequency of PACs was 2.7 (interquartile range 0.8-12.1). After multivariable adjustment, increasing age, increasing height, decreasing body mass index, and a history of myocardial infarction were each associated with more PACs. Regarding modifiable predictors, participants using beta-blockers had 21% less [95% confidence interval (95% CI) 9-30%, P = 0.001] and those performing at least moderate intensity exercise vs. lower intensity exercisers had 10% less (95% CI 1-18%, P = 0.03) PACs. Higher PAC frequency explained 34% (95% CI 22-57%, P < 0.0001) of the relationship between increasing age and AF risk and 27% (95% CI 10-75%, P = 0.004) of the relationship between taller height and AF risk. CONCLUSION:Enhancing physical activity and use of beta-blockers may represent fruitful strategies to mitigate PAC frequency. A substantial proportion of the excess risk of AF due to increasing age and taller height may be explained by an increase in PAC frequency.

Introduction

Left atrial (LA) tissue characteristics may play an important role in atrial fibrillation (AF) induction and perpetuation. Although frequently used in clinical practice, computed tomography (CT) has not been employed to describe differences in LA wall properties between AF patients and controls. We sought to noninvasively characterize AF-associated differences in LA tissue using CT.

Methods

CT images of the LA were obtained in 98 consecutive patients undergoing AF ablation and in 89 controls. A custom software algorithm was used to measure wall thickness and density in four prespecified regions of the LA.

Results

On average, LA walls were thinner (-15.5%, 95% confidence interval [CI] -23.2 to -7.8%, P < 0.001) and demonstrated significantly lower density (-19.7 Hounsfield Units [HU], 95% CI -27.0 to -12.5 HU, P < 0.001) in AF patients compared to controls. In linear mixed models adjusting for demographics, clinical variables, and other CT measurements, the average LA, interatrial septum, LA appendage, and anterior walls remained significantly thinner in AF patients. After adjusting for the same potential confounders, history of AF was associated with reduced density in the LA anterior wall and increased density below the right inferior pulmonary vein and in the LA appendage.

Conclusion

Application of an automated measurement algorithm to CT imaging of the atrium identified significant thinning of the LA wall and regional alterations in tissue density in patients with a history of AF. These findings suggest differences in LA tissue composition can be noninvasively identified and quantified using CT.

[This corrects the article DOI: 10.1371/journal.pone.0185228.].

[This corrects the article DOI: 10.1057/s41599-022-01338-7.].

Background

Patients with paroxysmal and persistent atrial fibrillation experience a similar risk of thromboembolism. Therefore, consensus guidelines recommend anticoagulant therapy in those at risk for thromboembolism irrespective of atrial fibrillation classification. We sought to examine whether there are differences in rates of appropriate oral anticoagulant treatment among patients with paroxysmal vs persistent atrial fibrillation in real-world cardiology practices.

Methods

We studied 71,316 outpatients with atrial fibrillation and intermediate to high thromboembolic risk (CHADS2 score ≥2) enrolled in the American College of Cardiology PINNACLE Registry between 2008 and 2012. Using hierarchical modified Poisson regression models adjusted for patient characteristics, we examined whether anticoagulant treatment rates differed between patients with paroxysmal vs persistent atrial fibrillation.

Results

The majority of outpatients (78.4%, n = 55,905) had paroxysmal atrial fibrillation. In both unadjusted and multivariable adjusted analyses, patients with paroxysmal atrial fibrillation were less frequently prescribed oral anticoagulant therapy than those with persistent atrial fibrillation (50.3% vs 64.2%; adjusted risk ratio [RR] 0.74; 95% confidence interval [CI], 0.72-0.76). Instead, patients with paroxysmal atrial fibrillation were prescribed more frequently only antiplatelet therapy (35.1% vs 25.0%; adjusted RR 1.77; 95% CI, 1.69-1.86) or neither antiplatelet nor anticoagulant therapy (14.6% vs 10.8%; adjusted RR 1.35; 95% CI, 1.26-1.44; P < .0001 for differences across all 3 comparisons).

Conclusions

In a large, real-world cardiac outpatient population, patients with paroxysmal atrial fibrillation with a moderate to high risk of stroke were less likely to be prescribed appropriate oral anticoagulant therapy and more likely to be prescribed less effective or no therapy for thromboembolism prevention.