Atrial fibrillation in athletes

The role of cardiopulmonary exercise testing in risk stratification and prognosis of atrial fibrillation: a scoping review of the literature

BACKGROUND

Cardiopulmonary exercise testing (CPET) is a significant tool for evaluating exercise capacity in healthy individuals and in various pulmonary and cardiovascular conditions, quantifying symptoms and predicting outcomes. Atrial fibrillation (AF) poses a significant burden on patients and health systems; a research marathon is ongoing for discovering the pathophysiologic substrate, natural history, prognostic tools and optimal treatment strategies for AF. Among the plethora of variables measured during CPET, there is a series of parameters of interest concerning AF.

METHODS

We conducted a scoping review aiming to identify significant CPET-related parameters linked to AF, as well as indicate the impact of other cardiac disease-related variables. We searched PubMed from its inception to 12 January 2022 for reports underlining the contribution of CPET in the assessment of patients with AF. Only clinical trials, observational studies and systematic reviews were included, while narrative reviews, expert opinions and other forms of manuscripts were excluded.

RESULTS

In our scoping review, we report a group of heterogeneous, thus noteworthy parameters relevant to the potential contribution of CPET in AF. CPET helps phenotype AF populations, evaluates exercise capacity after cardioversion or catheter ablation, and assesses heart rate response to exercise; peak VO₂ and VE/VCO₂, commonly measured indices during CPET, also serve as prognostic tools in patients with AF and heart failure.

CONCLUSIONS

CPET seems to hold a clinically important predictive value for future cardiovascular events both in patients with pre-existing cardiac conditions and in healthy individuals. CPET variables may play a fundamental role in the prediction of future AF-related events.

Relationship between echocardiographic characteristics and cardiac biomarkers during long-distance trail running

Background

Even if the beneficial cardiovascular effects of moderate exercise are recognized, effects of prolonged and intense exercise are still debated. This study aims to detect cardiovascular changes associated with long endurance running by assessing the relationship between echocardiographic parameters and cardiac biomarkers during long-distance trail running.

Methods

We performed a prospective observational study that included 20 participants who were all amateur runners (median age of 41 years old, still alive after a 7-year clinical follow-up) from 80-km trail running. All the participants underwent an echocardiographic examination and venous blood sampling before the race, at the intermediate refreshment checkpoints of the race (21st and 53rd km), and within 10 min after arrival.

Results

Mitral E/A velocity ratio and mitral TDI e’ wave were significantly decreased at the 21st km to arrival (p < 0.05). Mitral S wave and global longitudinal strain (GLS) were significantly decreased from the 53rd km to arrival (p < 0.05 for 53rd and 80th km). As compared to baseline, T-troponin and NT-proBNP were significantly increased at the 21st km in all the participants, but T-troponin values were systematically increased above the significative threshold. Diastolic echocardiographic abnormalities were mainly observed among participants with highest NT-proBNP (> 77 ng.l^–1) values at the 21st km. As compared to baseline, mitral e’ wave was significantly decreased (–35%) in participants with highest values of NT-proBNP. Similarly, GLS was also depressed among participants with highest troponin values at the 53rd km (p = 0.01 for 53rd km and p = 0.04 for arrival).

Conclusion

During the long-distance trail running, the early LV decrease in diastolic echocardiographic parameters is associated with increase in NT pro-BNP blood levels, and the decrease in LV systolic echocardiographic parameters later is associated with increase in T-troponin blood levels.

Hiatal Hernia: A Possible Trigger for Atrial Fibrillation

Atrial fibrillation is a commonly encountered clinical entity with various cardiovascular consequences. Common risk factors include alcohol abuse, hyperthyroidism, mitral stenosis, hypertension, diabetes mellitus, and coronary artery disease. Another risk factor, yet under scientific scrutiny, is hiatal hernia. This anatomical abnormality, due to its proximity to the heart and high prevalence in atrial fibrillation patients, has merited scientific investigation to determine if an association truly exists between this gastrointestinal pathology and atrial fibrillation. The case herein is of an 81-year-old hospitalized female with a hiatal hernia who was recorded to have recurrent episodes of atrial fibrillation in the absence of traditional risk factors for arrhythmogenesis.

Comparison of risk profiles for new-onset atrial fibrillation between patients aged <60 and ≥60 years

BACKGROUND

Atrial fibrillation (AF) has a heterogeneous pathophysiology according to individual patient characteristics. This study aimed to identify the effects of widely known risk factors on AF incidence according to age and to elucidate the clinical implications of these effects.

METHODS AND RESULTS

We analyzed data from 501,668 subjects (≥18years old) without AF and valvular heart disease from the Korean National Health Insurance Service-National Sample Cohort. The total population was divided into two groups according to age, <60years and ≥60years. AF occurred in 0.7% of the overall population (3,416 of 501,668) during the follow-up period (mean 47.6 months). In Cox regression analysis, age, male sex, previous ischemic stroke, heart failure, and hypertension were related to increased risk of new-onset AF in both age groups. Especially in the <60years age group, risk of new-onset AF was increased by relatively modifiable risk factors: obesity (body mass index ≥25kg/m2; hazard ratio[HR] 1.37 [1.22-1.55], p<0.001, interaction p<0.001), and hypertension (HR 1.93[1.69-2.22], p<0.001, interaction p<0.001). Although interactions were not significant, chronic obstructive pulmonary disease (HR 1.41[1.24-1.60], p<0.001) and chronic kidney disease (HR 1.28[1.15-1.41], p<0.001) showed increased trends of the risk of new-onset AF in the ≥60years age group.

CONCLUSION

The risk profile for new-onset AF was somewhat different between the <60years and the ≥60years age groups. Compared to the ≥60years group, relatively modifiable risk factors (such as obesity and hypertension) had a greater impact on AF incidence in the <60years age group. Different management strategies to prevent AF development according to age may be needed.

Heritability estimates of atrial fibrillation in Thoroughbred racehorses in Hong Kong and Australia

INTRODUCTION

Atrial fibrillation (AF) is the most common performance-limiting arrhythmia of racehorses. A genetic contribution has been suggested in Standardbred racehorses but has not been investigated in Thoroughbreds. The objective of this study was to determine the heritability of AF in Thoroughbred racehorses.

ANIMALS, MATERIALS AND METHODS

Horses racing between 2007 and 2019 in Hong Kong and Australia that had AF detected postrace via auscultation (n = 463 cases) were compared with five randomly selected racing contemporaries (n = 2,315 controls). The ASReml-R programme was used to fit an animal model to the AF data to estimate heritability using the entire data set and a subset of horses (n = 106 cases) that had electrocardiographic confirmation of AF. Variance components were estimated assuming AF was normally distributed and on the logit-transformed scale. The risk of producing AF-affected offspring was calculated using Fisher's exact test for stallions that sired ≥10 individuals in the case-control population.

RESULTS

Heritability on the underlying scale was 0.064 ± 0.04 (logit animal) and 0.071 ± 0.04 (normal animal) for the entire population and 0.065 ± 0.097 (logit animal) and 0.058 ± 0.11 (normal animal) for electrocardiographic-confirmed AF cases. Of 71 stallions that sired ≥10 individuals, three were more likely to produce affected offspring (odds ratio: 4.05-7.57; p < 0.01). Age (p = 0.991), sex (p = 0.830), and year of birth (p = 0.547) did not contribute to expression.

CONCLUSIONS

Although some stallions were overrepresented amongst affected horses, the heritability of AF in this population of Thoroughbreds was low. Environmental and individual factors contributing to AF development require further investigation.

Consumer wearable technologies to identify and monitor exercise-related arrhythmias in athletes

PURPOSE OF REVIEW

The aim of this study was to synthesize the current evidence supporting and against the use of wearable devices to detect underlying heart conditions in athletes and the most significant limitations.

RECENT FINDINGS

Although several large studies have been conducted to evaluate the ability of wearables devices to identify atrial fibrillation among the general population, no studies evaluating their ability to detect other exercise-related arrhythmias in athletes are very sparse. Most of the studies or case reports are focused on the wearables' reliability and accuracy compared with standard ECG. Only small studies evaluating the accuracy of one wearable device in athletes have been carried out to date. Unfortunately, none of them have investigated their ability to detect specific arrhythmias in the athletic population.

SUMMARY

Rapidly detecting dangerous arrhythmias in a symptomatic athlete continues to be an elusive goal. The use of smartphone ECG monitors can provide diagnostic data in athletes with symptoms that could represent a helpful instrument. However, many uncertainties remain and need to be addressed and validated in large-scale trials to incorporate these devices into the healthcare system and be part of an athlete's daily monitoring and healthcare.

Posttraumatic Stress Disorder and Risk for Early Incident Atrial Fibrillation: A Prospective Cohort Study of 1.1 Million Young Adults

Background Acute psychological stress and negative emotions are known risk factors for atrial fibrillation (AF). Whether exposure to chronic stress syndromes, such as posttraumatic stress disorder (PTSD), also increases susceptibility to AF is unknown. Methods and Results We prospectively assessed the incidence of AF over a 13-year period among 988 090 young and middle-aged veterans (mean age, 30.29±9.19 years; 87.8% men, 64.5% white) who first accessed care through the Veterans Health Administration from October 2001 to November 2014 and were free of AF, atrial flutter, or atrial tachycardia at baseline. Time-varying, multivariate Cox proportional hazard models were used to examine the independent contribution of PTSD to new AF. We also tested for effect modification by sex and controlled for healthcare use. During a mean follow-up of 4.8 years, 2491 patients were diagnosed with AF. Patients with PTSD had a higher overall incidence of AF (P<0.0001) and were more likely to develop AF at a younger age than those without PTSD (P=0.004). PTSD was significantly associated with incident AF in unadjusted models (hazard ratio, 1.31; 95% CI, 1.19-1.43) and models that adjusted for demographics, lifestyle factors, cardiovascular risk factors, and depression (hazard ratio, 1.13; 95% CI, 1.02-1.24). The interaction with sex was nonsignificant (P=0.93). Conclusions PTSD was associated increased risk for early incident AF after adjustment for established AF risk factors and depression in this cohort of young and middle-aged veterans. Findings from this study require validation in more diverse populations to determine their generalizability.

Influence of Continuous Training on Atrial Myocytes IK1 and IKAch and on Induction of Atrial Fibrillation in a Rabbit Model

BACKGROUND

Elucidation of mechanisms underlying continuous training-related atrial fibrillation (AF) may inform formulation of novel therapeutic approaches and training method selection. This study was aimed at assessing mechanisms underlying continuous training-induced AF in an animal model.

METHODS

Healthy New Zealand rabbits were divided into three groups (n=8 each), namely, control (C), and moderate intensity (M), and high intensity (H) continuous training according to treadmill speed. Atrial size andintrinsic and resting heart rates were measured by transthoracic echocardiography before, and 8 and 12 weeks after training. Using a Langendorff perfusion system, AF was induced by S1S2 stimulation and the induction rate was recorded. Atrial IK1 and IKAch ion current densities were recorded using whole-cell patch-clamp technique in isolated atrial myocytes. Changes in atrial Kir2.1, Kir2.2, Kir3.1, and Kir3.4 mRNA expression were assessed by reverse transcriptase-coupled polymerase chain reaction.

RESULTS

After 8 and 12 weeks, Groups M and H vs. Group C had greater (all P < 0.05) atrial anteroposterior diameter; greater incidence of AF (60% and 90% vs. 45%, respectively; P < 0.05, also between Groups H and M); and greater atrial IKAch current density. In Group H, Kir2.1 and Kir2.2 mRNA expression in the left and right atria was increased (P < 0.05, vs. Groups C and M) as was left atrial Kir3.1 and Kir3.4 mRNA expression (P < 0.05, vs. Group C).

CONCLUSION

In a rabbit model, continuous training enlarges atrial diameter leading to atrial structural and electrical remodeling and increased AF incidence.

Competitive Endurance Activities of Middle-aged Athletes as a Risk Factor for Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia in athletes. Epidemiological studies have documented a greater prevalence of AF in athletes engaged in long-term endurance sports. Several mechanisms were proposed to underlie the association between exercise and AF, but the exact pathophysiology remains unclear. The studies up to now have been concentrated on the competitive middle-aged endurance athletes, but there is no evidence of AF prevalence among highly active noncompetitive athletes of the same age. Endurance athletes who do not compete might be at a lower risk for AF than their competitive peers. This hypothesis is theoretically examined, and the current evidence summarized in this article.

Physical activity volume in relation to risk of atrial fibrillation. A non-linear meta-regression analysis

Background

Light physical activity is known to reduce atrial fibrillation risk, whereas moderate to vigorous physical activity may result in an increased risk. However, the question of what volume of physical activity can be considered beneficial remains poorly understood. The scope of the present work was to examine the relation between physical activity volume and atrial fibrillation risk.

Design

A comprehensive systematic review was performed following the PRISMA guidelines.

Methods

A non-linear meta-regression considering the amount of energy spent in physical activity was carried out. The first derivative of the non-linear relation between physical activity and atrial fibrillation risk was evaluated to determine the volume of physical activity that carried the minimum atrial fibrillation risk.

Results

The dose–response analysis of the relation between physical activity and atrial fibrillation risk showed that physical activity at volumes of 5–20 metabolic equivalents per week (MET-h/week) was associated with significant reduction in atrial fibrillation risk (relative risk for 19 MET-h/week = 0.92 (0.87, 0.98). By comparison, physical activity volumes exceeding 20 MET-h/week were unrelated to atrial fibrillation risk (relative risk for 21 MET-h/week = 0.95 (0.88, 1.02).

Conclusion

These data show a J-shaped relation between physical activity volume and atrial fibrillation risk. Physical activity at volumes of up to 20 MET-h/week is associated with reduced atrial fibrillation risk, whereas volumes exceeding 20 MET-h/week show no relation with risk.

The heart remains the core: cardiac causes of poor performance in horses compared to human athletes

Cardiac remodelling occurs in response to exercise and is generally beneficial for athletic performance due to the increase in cardiac output. However, this remodelling also may lead to an increased prevalence of cardiac murmurs and arrhythmias. In most cases, these are not considered to be significant. However, in some cases, there may be potentially deleterious consequences. Whilst sudden cardiac death (SCD) is a rare occurrence, the consequences are catastrophic for both the horse and potentially the rider or driver. Furthermore, the sudden death of a horse in the public arena has negative connotations in regards to public perception of welfare during equestrian sports. Prediction of which individuals might be susceptible to potential deleterious effects of exercise is a focus of interest in both human and equine athletes but remains a challenge because many athletes experience cardiac murmurs and exercise-induced arrhythmias that are clinically irrelevant. This review summarises the effects of exercise on cardiac remodelling in the horse and the potential effects on athletic performance and SCD. The use of biomarkers and their future potential in the management of athletic horses is also reviewed.

Are heart rate monitors valuable tools for diagnosing arrhythmias in endurance athletes?

Millions of physically active individuals worldwide use heart rate monitors (HRMs) to control their exercise intensity. In many cases, the HRM indicates an unusually high heart rate (HR) or even arrhythmias during training. Unfortunately, studies assessing the reliability of these devices to help control HR disturbances during exercise do not exist. We examined 142 regularly training endurance runners and cyclists, aged 18-51 years, with unexplained HR abnormalities indicated by various HRMs to assess the utility of HRMs in diagnosing exertion-induced arrhythmias. Each athlete simultaneously wore a Holter electrocardiogram (ECG) recorder and an HRM during typical endurance training in which they had previously detected "arrhythmias" to verify the diagnosis. Average HRs during exercise were precisely recorded by all types of HRMs. No signs of arrhythmia were detected during exercise in approximately 39% of athletes, and concordant HRs were recorded by the HRMs and Holter ECG. HRMs indicated surprisingly high short-term HRs in 45% of athletes that were not detected by the Holter ECG and were artifacts. In 15% of athletes, single ventricular/supraventricular beats were detected by the Holter ECG but not by the HRM. We detected a serious tachyarrhythmia in the HRM and Holter ECG data with concomitant clinical symptoms in only one athlete, who was forced to cease exercising. We conclude that the HRM is not a suitable tool for monitoring heart arrhythmias in athletes and propose an algorithm to exclude the suspicion of exercise-induced arrhythmia detected by HRMs in asymptomatic, physically active individuals.

Endurance Exercise and the Heart: Friend or Foe?

Although low- to moderate-intensity exercise has well-known cardiovascular benefits, it has been increasingly suggested that prolonged strenuous endurance exercise (SEE) could have potential deleterious cardiac effects. In effect, the term 'cardiac overuse injury' (or 'over-exercise') has been recently reported to group all the possible deleterious cardiac consequences of repeated exposure to SEE or 'over-exercise'. In this article, we provide a balanced overview of the current state of knowledge regarding the 'pros' and 'cons' of SEE from a cardiological point of view.

Exercise and Arrhythmias: A Double-Edged Sword

Ample evidence indicates that moderate regular exercise is beneficial for both normal individuals and patients with cardiovascular (CV) disease. However, intense and strenuous exercise in individuals with evident or occult underlying CV abnormalities may have adverse effects with provocation and exacerbation of arrhythmias that may lead to life-threatening situations. Both of these aspects of exercise-induced effects are herein reviewed.

Atrial Fibrillation In Athletes: Pathophysiology, Clinical Presentation, Evaluation and Management

Atrial fibrillation (AF) is the most common cardiac arrhythmia in athletes, especially in middle-aged athletes. Studies have demonstrated that athletes who engage in endurance sports such as runners, cyclists and skiers are more prone to AF than other athletes. The effects of exercise on the onset and progression of AF is complex. Triggers of AF in athletes may include atrial ectopy and sports supplements. Substrates for AF in athletes include atrial remodeling, fibrosis, and inflammation. Modulators of AF in athletes include autonomic activation, electrolyte abnormalities, and possibly, gastroesophageal reflux. Management of AF in athletes with rate-controlling agents and antiarrhythmic drugs remains a challenge and can be associated with impaired athletic performance. The value of catheter ablation is emerging and should be considered in suitable athletes with AF.

Left atrial remodeling, early repolarization pattern, and inflammatory cytokines in professional soccer players

OBJECTIVES

Although regular physical exercise clearly reduces cardiovascular morbidity risk, long-term endurance sports practice has been recognized as a risk factor for atrial fibrillation (AF). However, the mechanisms how endurance sports can lead to AF are not yet clear. The aim of our present study was to investigate the influence of long-term endurance training on vagal tone, atrial size, and inflammatory profile in professional elite soccer players.

METHODS

A total of 25 professional major league soccer players (mean age 24±4 years) and 20 sedentary controls (mean age 26±3 years) were included in the study and consecutively examined. All subjects underwent a sports cardiology check-up with physical examination, electrocardiography, echocardiography, exercise testing on a bicycle ergometer, and laboratory analysis [standard laboratory and cytokine profile: interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-8, IL-10].

RESULTS

Athletes were divided into two groups according to presence or absence of an early repolarization (ER) pattern, defined as a ST-segment elevation at the J-point (STE) ≥0.1mm in 2 leads. Athletes with an ER pattern showed significantly lower heart rate and an increased E/e' ratio compared to athletes without an ER pattern. STE significantly correlated with E/e' ratio as well as with left atrial (LA) volume. The pro-inflammatory cytokines IL-6, IL-8, TNF-α as well as the anti-inflammatory cytokine IL-10 were significantly elevated in all soccer players. However, athletes with an ER pattern had significantly higher IL-6 plasma levels than athletes without ER pattern. Furthermore, athletes with "high" level IL-6 had significantly larger LA volumes than players with "low" level IL-6.

CONCLUSIONS

Athletes with an ER pattern had significantly higher E/e' ratios, reflecting higher atrial filling pressures, higher LA volume, and higher IL-6 plasma levels. All these factors may contribute to atrial remodeling over time and thus increase the risk of AF in long-term endurance sports.

Effect of years of endurance exercise on risk of atrial fibrillation and atrial flutter

Emerging evidence suggests that endurance exercise increases the risk for atrial fibrillation (AF) in men, but few studies have investigated the dose-response relation between exercise and risk for atrial arrhythmias. Both exposure to exercise and reference points vary among studies, and previous studies have not differentiated between AF and atrial flutter. The aim of this study was to assess the risk for atrial arrhythmias by cumulative years of regular endurance exercise in men. To cover the range from physical inactivity to long-term endurance exercise, the study sample in this retrospective cohort study was based on 2 distinct cohorts: male participants in a long-distance cross-country ski race and men from the general population, in total 3,545 men aged ≥ 53 years. Arrhythmia diagnoses were validated by electrocardiograms during review of medical records. Regular endurance exercise was self-reported by questionnaire. A broad range of confounding factors was available for adjustment. The adjusted odds ratios per 10 years of regular endurance exercise were 1.16 (95% confidence interval 1.06 to 1.29) for AF and 1.42 (95% confidence interval 1.20 to 1.69) for atrial flutter. In stratified analyses, the associations were significant in cross-country skiers and in men from the general population. In conclusion, cumulative years of regular endurance exercise were associated with a gradually increased risk for AF and atrial flutter.

Risk factors and genetics of atrial fibrillation

Atrial fibrillation (AF) is by far the most common sustained tachyarrhythmia, affecting 1% to 2% of the general population. AF prevalence and the total annual cost for treatment are alarming, emphasizing the need for an urgent attention to the problem. Thus, having up-to-date information on AF risk factors and appreciating how they promote maintenance of AF maintenance are essential. This article presents a simplified examination of AF risk factors, including emerging genetic risks.

Increased risk of atrial fibrillation among elderly Norwegian men with a history of long-term endurance sport practice

Atrial fibrillation (AF) is the most common cardiac arrhythmia. The prevalence increases with increasing age. In middle-aged men, endurance sport practice is associated with increased risk of AF but there are few studies among elderly people. The aim of this study was to investigate the role of long-term endurance sport practice as a risk factor for AF in elderly men. A cross-sectional study compared 509 men aged 65-90 years who participated in a long-distance cross-country ski race with 1768 men aged 65-87 years from the general population. Long-term endurance sport practice was the main exposure. Self-reported AF and covariates were assessed by questionnaires. Risk differences (RDs) for AF were estimated by using a linear regression model. After multivariable adjustment, a history of endurance sport practice gave an added risk for AF of 6.0 percent points (pp) (95% confidence interval 0.8-11.1). Light and moderate leisure-time physical activity during the last 12 months reduced the risk with 3.7 and 4.3 pp, respectively, but the RDs were not statistically significant. This study suggests that elderly men with a history of long-term endurance sport practice have an increased risk of AF compared with elderly men in the general population.

Endurance Sport Activity and Risk of Atrial Fibrillation - Epidemiology, Proposed Mechanisms and Management

There is evidence for a higher prevalence of atrial fibrillation (AF) in athletes engaged in long-term endurance sports training compared with the general population. Although atrial anatomic adaptations, alterations in autonomic nervous system, chronic systemic inflammation and fibrosis have been proposed as potential mechanisms, they remain speculative. Medical therapy with long-term antiarrhythmic agents or 'pill in the pocket' medications is hampered by limitations, such as sports eligibility and interference with exercise tolerance. AF ablation represents a valid therapeutic option with results similar to these achieved in other patients. Nevertheless, further clinical trials are needed to confirm whether endurance sport practice affects the maintenance of sinus rhythm following catheter ablation of AF.

Exercise, the athlete's heart, and sudden cardiac death

Physical activity is a potent therapy for both the prevention and treatment of cardiovascular disease. Exercise appears to most benefit people who are the least active. There is some evidence to suggest that a curvilinear relationship exists between exercise and survival, whereby beyond an optimal level of fitness, the principle of diminishing returns applies. Indeed, some go further in suggesting that there is evidence that extreme athletic training may be harmful in some individuals. The incidence of sudden cardiac death in athletes is greater than in matched, nonathletic counterparts, and this finding is driven by the provocation of an underlying cardiac abnormality by strenuous exertion. The task of detecting pathological myocardial substrate in athletes is made difficult by physiological adaptations to exercise that can mimic the appearance of cardiomyopathies and ion channelopathies in some individuals. This article details the clinical evaluation of the athlete with reference limits for cardiac physiological remodeling and discusses the diagnostic dilemmas that arise.

[Atrial fibrillation and physical activity]

Atrial fibrillation is the most frequent arrhythmia. Its "lone" form (when underlying pathology is not discovered) can be detected in a small percentage of endurance sports participants, and in growing numbers among veterans, probably as a result of some cardiac or other irregularities. Enhanced vagal tone and sudden sympathetic impulse, repetitive oxidative stress, inflammatory processes, enlarged atria, electric instabilization can explain the higher occurrence. Treatment of atrial fibrillation enables the affected persons to participate in regular medium-intensity exercise, 3-5 hours a week, which offers a protective role against cardiovascular, metabolic and mental illnesses.

Atrial fibrillation and acid reflux disease

To date, the precise mechanism of atrial fibrillation (AF) as a possible cause of reflux disease remains uncertain, although some possibilities can be postulated. Inflammation and vagal stimulation may have a key role linking these 2 common diseases. There is some evidence in the form of case reports and limited observational studies reporting that reflux disease, and more specifically esophagitis, can cause paroxysmal AF, and various mechanisms have been proposed. Some studies have demonstrated that acid suppressive therapy by proton pump inhibitors (PPIs) may help ameliorate symptoms associated with AF and also facilitate conversion to normal sinus rhythm in a subset of patients. Further prospective studies are needed to determine if a true causal mechanism exists between the two and assess whether the mechanism is dependent on a specific subtype of AF. In addition, the response of AF-related symptoms to PPI therapy and the potential for PPI therapy to reduce the development of AF merits further investigation.