Asymptomatic Atrial Fibrillation Episodes Research Articles

Skin sympathetic nerve activity in symptomatic and asymptomatic paroxysmal atrial fibrillation

BackgroundThe causes of symptoms in patients with paroxysmal atrial fibrillation (AF) remains unclear. ObjectiveThe purpose of this study was to correlate the magnitudes of skin sympathetic nerve activity (SKNA) with symptoms in patients with AF. MethodsWe prospectively enrolled patients with symptomatic paroxysmal AF for ambulatory electrocardiography and SKNA recording. Heart rhythms at the time of symptoms were categorized as AF or normal sinus rhythm (NSR). Maximal and average skin sympathetic nerve activity (aSKNA) and heart rate (HR) were compared between symptomatic and asymptomatic AF and NSR episodes using mixed effects models to account for within-patient correlations. ResultsAmong the 31 enrolled patients, 16 (52%) had at least 1 episode of AF, and 24 (77%) endorsed symptoms during the monitoring period. Compared with asymptomatic AF episodes, symptomatic AF episodes had higher maximal aSKNA (1.260 [interquartile range (IQR) 1.114–1.723] μV vs 1.108 [IQR 0.974–1.312] μV; P <0.001) and higher maximal HR (152 ± 24 bpm vs 132 ± 19 bpm; P <.001). Symptomatic NSR episodes were associated with higher maximal aSKNA (1.612 [IQR 1.287–2.027] μV vs 1.332 [IQR 1.033–1.668] μV; P = .001) and higher maximal HR (152 ± 24 bpm vs 105 ± 16 bpm; P <.001) than asymptomatic NSR episodes. Of the symptomatic episodes, 66 (73%) occurred during NSR and 24 (27%) during AF. All P values were obtained from mixed effects models. ConclusionSymptomatic episodes in patients with paroxysmal AF were more frequently associated with NSR than AF. Symptomatic AF and NSR episodes were associated with higher aSKNA than asymptomatic episodes. In patients with paroxysmal AF, symptoms correlate better with SKNA than heart rhythm.

Episode-level characteristics of atrial fibrillation are associated with symptomatic events

Abstract Background Symptoms related to Atrial Fibrillation (AF) can be debilitating are the main driver to seek hospital attention. However, many patients do not experience any symptoms and intra-subject variation is also seen. The reasons for this variability are unclear and a better understanding of the features associated with symptomatic AF episodes may improve stratification and personalisation of care. Purpose To evaluate the features associated with symptomatic versus asymptomatic AF episodes recorded using an insertable cardiac monitor (ICM). Methods We linked a deidentified database of aggregated electronic health records from 2007-2021 to a manufacturer’s device data warehouse with continuous diagnostic monitoring data. ICM-detected AF episodes of a minimum of one hour duration were retrospectively analysed. Symptomatic AF was defined as episodes temporally correlated with patient activation of a handheld symptom activator device. Episode- level comparison of mean heart rate at detection and during the entire AF episode, AF episode duration, activity index and AF evidence score (a linear scale based on episode irregularity) between symptomatic and asymptomatic patients was performed. Data was reported as mean ± standard deviation or median (inter-quartile range) if non-normally distributed. Wilcoxon Signed-Rank test was used for per-subject paired analysis. Multi-variate logistic regression model with binomial distribution and exchangeable correlation structure was used to identify factors associated with symptomatic episodes. A Generalized Estimating Equations model was used to account for multiple AF episodes within a subject. Results 417,432 unique episodes were recorded in 11,436 patients. 6,190 (1.48%) episodes from 1776 patients were marked as symptomatic. These were longer (5.5 (12.1) hours vs 3.7 (9.3) hours), had a higher mean HR at onset (105.7±29.3bpm vs 89.1+-24.6bpm) and a greater AF evidence score (97.6+-26.9 vs 82.1+-24.4). On multi- variate logistic regression, AF evidence score, and mean HR was independently associated with symptomatic AF (table 1). Per subject analysis of 1589 patients with both symptomatic and asymptomatic episodes also suggested significantly higher AF evidence scores. (-3.64±22.0). Discussion: This is the largest episode-level characterisation of AF episodes in patients with an ICM. The AF evidence score, a marker of ventricular rate variability, may be useful for the remote stratification of AF episodes. Prospective study of stratification based on this parameter would be of value.Regression model of symptomatic AF

Safety and Efficacy of Patent Foramen Ovale Device Closure: Evaluation of Outcomes in a Tertiary Referral Center

Abstract Aim and Objectives: Recent randomized controlled trials have demonstrated the benefit of patent foramen ovale (PFO) device closure over medical therapy alone for secondary prevention of cryptogenic stroke in carefully selected patients. In the current study, we sought to investigate the outcomes and complications of PFO device closure in our referral tertiary cardiovascular center. Materials and Methods: In this retrospective study, 155 adult patients who underwent PFO device closure between 2006 and 2021 were included. Patient characteristics, recurrent neurologic events, and procedure-related complications were evaluated. Results: The follow-up period was 2.3 ± 1.2 years. The average age of the participants was 41.3 ± 10 years, and 59.4% were male. Six patients (3.9%) suffered recurrent cerebrovascular events in the follow-up. No procedure-related complications were reported in our study population. Two patients (1.3%) with recurrent stroke had developed newly diagnosed atrial fibrillation (AF). Conclusion: PFO device closure is a safe and effective method for the prevention of recurrent ischemic stroke in patients with no other detectable etiology. Patients, particularly those with cardiovascular risk factors, should be meticulously investigated for the asymptomatic episodes of AF as the contributing factor with prolonged Holter monitoring or use of loop recorders.

Left atrial strain as a predictor of atrial fibrillation in patients with asymptomatic severe aortic stenosis and preserved left ventricular systolic function

Aim. To study the structural and functional left heart parameters in patients with severe aortic stenosis (AS) and preserved ejection fraction (EF) in order to determine the risk of atrial fibrillation (AF).Material and methods. The study included 84 patients (men, 37; mean age, 68±8 years) with severe AS and EF &gt;55%. All patients had sinus rhythm and were asymptomatic. Echocardiography was performed to assess longitudinal strain of the left ventricle (LVLS), right ventricle, left atrium (LALS) and the left atrial stiffness (LAS) using the speckle tracking method. Left ventricular mass index (LVMI) and maximum left atrium volume index (LAVI) were also determined. Patients were followed up for 1 year.Results. AF was reported in 27 (32%) patients, of which 9 (33%) had asymptomatic AF episodes detected by 48-hour electrocardiography. Eighteen (67%) patients with AF felt palpitations. Patients with and without episodes of atrial fibrillation had non-significant differences in LVMI, LAVI, and LVLS. Patients with atrial fibrillation had a lower LALS and a higher LAS compared with patients without atrial fibrillation. Regression analysis revealed that LALS and LAS were independent predictors of AF.Conclusion. AF develops in about one third of asymptomatic patients with severe AS and normal EF. The development of AF predisposes to the onset of AS symptoms in most patients. LALS and LAS were predictors of AF in these patients. Identification of patients at risk of AF will allow for earlier aortic valve replacement.

Advantages of using a portable cardiac monitor in outpatients with paroxysmal atrial fibrillation

Aim. To study the advantages of using a portable electrocardiographic (ECG) monitor in outpatients with paroxysmal atrial fibrillation (AF).Material and methods. We examined 88 patients (26 men, 62 women, mean age, 63 [57;68] years) with paroxysmal AF with an average frequency of arrhythmia episodes of 1,0 [0.3;3.75] per month. Forty three (49%) patients were included in the remote monitoring (RM) group using the ECG Dongle monitor, and 45 (51%) patients were included in the conventional monitoring (CM) group. Patients underwent scheduled examinations 2, 6 and 12 months after the start of therapy. Unscheduled consultations were carried out in case of AF recurrence. Patients from the RM group, using portable cardiac monitor, additionally self-registered ECG 1 time per week and in case of symptoms suggestive of AF. ECG strips were sent to the clinical investigator for analysis.Results. With the help of portable cardiac monitor, 2477 ECG strips were collected and analyzed: 2159 (87,2%) — sinus rhythm, 318 (12,8%) — AF and atypical atrial flutter. Forty four episodes of AF in 3 patients were asymptomatic. In addition, 211 (8,5%) sinus rhythm ECG strips were recorded by 13 patients with symptoms suggestive of AF. In the RM group, 7 (16%) patients were hospitalized due to recurrent AF, while in the CM group, 20 (44%) patients (p=0,004). The total number of emergency hospitalizations was 8 and 29 in the RM and CM groups, respectively. The number of patients who called an ambulance was significantly lower in the RM group: in the CM group, 37 calls for an ambulance were made by 22 patients, while in the RM group — 12 patients made 15 calls (p=0,044). The proportion of calls followed by hospitalization (40 vs 70%, p=0,043) was significantly lower in the RM group.Conclusion. Remote ECG monitoring using the ECG Dongle system is a useful way to monitor patients with paroxysmal AF, which make it possible to register asymptomatic AF episodes, differentiate the causes of palpitations, and significantly reduce the frequency of emergency calls and hospitalizations.

EVALUATION OF ATRIAL FIBRILLATION BURDEN AFTER THE FIRST ECG-DOCUMENTED EPISODE VIA IMPLANTABLE LOOP RECORDERS

Objective: The natural history of paroxysmal atrial fibrillation (AF) after the first clinical AF episode is not well known. AF burden is of clinical significance as it may have clinical implications concerning the long-term management of the arrhythmia and the decision-making on AF patients. We studied the natural history of AF in patients after their first clinical AF episode. Design and method: Thirty consecutive patients (age 66.9 ± 10 years; 14 men) received an implantable loop recorder (ILR) (Reveal XT 9529; Medtronic, Minneapolis, Minnesota, USA) after their first symptomatic paroxysmal AF episode. We recorded the AF recurrences and burden (clinical and subclinical AF) during a follow-up period of three years. We excluded patients with persistent or permanent AF and patients with AF attributed to reversible or transient causes. Results: Eight patients (26.6%) did not present any AF recurrence during the first year of the follow-up period. Five patients (16.6%) did not also suffer any AF episode during the second year, while in three patients (10%) no AF episode was recorded during the three-year follow-up period. In 16 patients (53.3%) the AF burden was increased during the second year of follow-up period while in 9 patients (30%) the AF burden was decreased. During the third year of follow-up period the AF burden was increased in 19 patients (63.3%), decreased in 7 patients (23.3%) and remained almost the same in 4 patients (13.3%). Five patients (16.6%) presented at least one episode of persistent AF during the follow-up period. Seven patients (23.3%) suffered only from symptomatic AF episodes, while in nine patients (30%) only asymptomatic AF episodes were recorded. Eleven patients (36.7%) had both types of AF episodes (symptomatic and asymptomatic). Conclusions: The AF recurrences and burden increased in most AF patients during the three-year follow-up period. However, some patients did not suffer any AF recurrence or they presented a decrease in AF burden. Paroxysmal AF clinical profile differs among the AF patients significantly and this indicates that an individualized approach via long-term rhythm monitoring may be of clinical significance, at least in some newly diagnosed AF patients.

Atrial fibrillation progression and burden after the first clinical episode: a prospective observational study via implantable loop recorders

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Medtronic Inc Background The progression of atrial fibrillation (AF) after the first clinical AF episode is not well known. AF burden is of clinical significance as it may have clinical implications concerning the long-term management of the arrhythmia and the decision-making on AF patients. Continuous rhythm monitoring via implantable loop recorders (ILRs) can precisely evaluate the AF recurrence profile. Purpose To observe the AF progression and AF burden in patients after their first clinical AF episode. Methods Thirty consecutive patients (age 66.9 ± 10 years; 14 men) received an ILR after their first clinical AF episode. We recorded the AF recurrences and burden during a follow-up period of three years. We excluded patients with persistent or permanent AF and patients with an episode of AF attributed to reversible or transient causes. Results Three patients (10%) had no AF recurrence, whereas 4 patients (13.3%) presented only one episode. Almost half of the patients (46.7%) had a low recurrence rate (&amp;lt;5 episodes/year), whereas the majority of patients (19/30) suffered from episodes with maximum duration ≤24 hours. Eleven patients (36.7%) presented either no episode or a low recurrence rate with episodes lasting ≤24 hours. In 16 patients (53.3%) the AF burden was increased during the second year of follow-up period while in 9 patients (30%) the AF burden was decreased. During the third year of follow-up period the AF burden was increased in 19 patients (63.3%), decreased in 7 patients (23.3%) and remained almost the same in 4 patients (13.3%). Five patients (16.6%) presented at least one episode of persistent AF during the follow-up period. Seven patients (23.3%) suffered only from symptomatic AF episodes, while in nine patients (30%) only asymptomatic AF episodes were recorded. Eleven patients (36.7%) had both types of AF episodes (symptomatic and asymptomatic). Conclusions The AF recurrences and burden increased in most AF patients. However, a significant percentage of patients either suffer no AF recurrence after their first symptomatic episode or show a low recurrence rate. Most patients present episodes of short duration. Paroxysmal AF clinical profile differed significantly among the patients. If these findings are confirmed in larger studies, they could have clinical implications ensuring individualized management of the arrhythmia in the future in newly diagnosed AF patients.

Predictive Value of Left Atrial and Ventricular Strain for the Detection of Atrial Fibrillation in Patients With Cryptogenic Stroke.

Background and AimsCryptogenic stroke (CS) is associated with a high rate of recurrences and adverse outcomes at long-term follow-up, especially due to its unknown etiology that often leads to ineffective secondary prevention. Asymptomatic atrial fibrillation (AF) could play an important pathophysiological role. Some studies have pointed to left atrial (LA) and left ventricular (LV) systolic and diastolic dysfunction as surrogate markers of AF. The aim of the study is to evaluate the relationship between echocardiographic parameters of LA and LV function, and the occurrence of AF revealed by continuous ECG monitoring in a cohort of patients with CS.MethodsSingle-center prospective cohort study. Seventy-two patients with CS with insertable cardiac monitors (ICM) underwent transthoracic echocardiography (TTE). TTE was focused on LA and LV function, including both standard and longitudinal strain-derived parameters. All detected AF episodes lasting more than 2 min were considered.ResultsContinuous ECG monitoring revealed subclinical AF in 23 patients (32%) at an average of 6.5 months after ICM implantation. Many echocardiographic parameters, indicating LA volume and LV systolic/diastolic function, were significantly associated with the occurrence of AF, suggesting the worst atrial function in the AF group. Furthermore, multivariable regression analysis revealed that peak atrial contraction strain and left ventricular strain were independently associated with AF (adjusted OR = 0.72, CI 95% 0.48–0.90, p = 0.005, and adjusted OR = 0.69, CI 95% 0.46–0.95, p = 0.041, respectively).ConclusionIn patients with CS, LA and LV strain analysis add predictive value for the occurrence of AF over clinical and morpho-functional echocardiographic parameters. Impaired booster pump strain and LV longitudinal strain are strong and independent predictors of AF.

Subclinical Atrial Fibrillation: A Silent Threat with Uncertain Implications.

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. Implantable and wearable cardiac devices have enabled the detection of asymptomatic AF episodes-termed subclinical AF (SCAF). SCAF, the prevalence of which is likely significantly underestimated, is associated with increased cardiovascular and all-cause mortality and a significant stroke risk. Recent advances in machine learning, namely artificial intelligence-enabled ECG (AI-ECG), have enabled identification of patients at higher likelihood of SCAF. Leveraging the capabilities of AI-ECG algorithms to drive screening protocols could eventually allow for earlier detection and treatment and help reduce the burden associated with AF.

P1014The natural history of atrial fibrillation after the first clinical episode: a prospective observational study via implantable loop recorders

Abstract Funding Acknowledgements The study was supported by Medtronic Inc Background The natural history of paroxysmal atrial fibrillation (AF) after the first clinical AF episode is not well known. AF burden is of clinical significance as it may have clinical implications concerning the long-term management of the arrhythmia and the decision-making on AF patients. Purpose To observe the natural history of AF in patients after their first clinical paroxysmal AF episode. Methods Thirty consecutive patients (age 66.9 ± 10 years; 14 men) received an implantable loop recorder (ILR) after their first symptomatic paroxysmal AF episode. We recorded the AF recurrences and burden (clinical and subclinical AF) during a follow-up period of three years. We excluded patients with persistent or permanent AF and patients with an episode of AF attributed to reversible or transient causes. Results Eight patients (26.6%) did not present any AF recurrence during the first year of the follow-up period. Five patients (16.6%) did not also suffer any AF episode during the second year, while in three patients (10%) no AF episode was recorded during the three-year follow-up period. In 16 patients (53.3%) the AF burden was increased during the second year of follow-up period while in 9 patients (30%) the AF burden was decreased. During the third year of follow-up period the AF burden was increased in 19 patients (63.3%), decreased in 7 patients (23.3%) and remained almost the same in 4 patients (13.3%). Five patients (16.6%) presented at least one episode of persistent AF during the follow-up period. Seven patients (23.3%) suffered only from symptomatic AF episodes, while in nine patients (30%) only asymptomatic AF episodes were recorded. Eleven patients (36.7%) had both types of AF episodes (symptomatic and asymptomatic). Conclusions The AF recurrence and burden increased in most AF patients during the three-year follow-up period. However, some patients did not suffer any AF recurrence or they presented a decrease in AF burden. Paroxysmal AF clinical profile differs among the AF patients significantly and this indicates that an individualized approach via long-term rhythm monitoring may be of clinical significance, at least in some newly diagnosed AF patients.

High incidence of subclinical atrial fibrillation in patients with syncope monitored with implantable cardiac monitor

ObjectiveThe use of implantable cardiac monitors (ICM) is highly useful in syncope workup. Latest-generation devices can detect asymptomatic episodes of atrial fibrillation. The main objective of this study was to determine the incidence of subclinical atrial fibrillation (AF) detected in a patient population undergoing prolonged electrocardiographic monitoring with an ICM for the etiological workup of syncope. MethodsProspective observational study carried out in a tertiary hospital from April 2014 to October 2019. All consecutive adult patients monitored with a latest-generation ICM for syncope with no prior history of AF were included in the analysis. ResultsOf a total of 509 ICMs implanted during the study period, 208 patients fulfilled the inclusion criteria. 42 patients (20.2%) were found to have AF on ICM. The incidence of AF was 11.7 cases per 100 person-years (95% CI: 8.7–15.9 per 100 person-years). The median burden of AF was 0.2% (IQR 0–0.8%). Age, the presence of hypertension, chronic kidney disease, the size of the septum and left atrium on electrocardiogram and the presence of broad QRS on baseline electrocardiogram were predictors for the appearance of AF in the univariate analysis. ConclusionThe incidental finding of atrial fibrillation in patients with syncope monitored with ICM is common. The burden of AF is low, and it is generally subclinical. These findings create added value for the use of ICM in the workup for syncope, although further studies are needed to determine the clinical benefit of documenting subclinical AF.

Abstract WP258: Effectiveness of Detection Asymptomatic Episodes of Atrial Fibrillation in Heart Failure Patients With Cardioverter Defibrillator

Introduction: Implantable cardioverter defibrillators due to the possibility of continuous recording of intracardiac electrograms can detect episodes of atrial fibrillation. In practice, this allows better identification of patients with asymptomatic AF episodes, thus increasing the proportion of patients who may benefit from pharmacological prophylaxis of thromboembolic events, particularly stroke. Hypothesis: If intracardiac electrogram analysis should be part of each visit carried out in patients with implantable cardioverter defibrillator, how much of detected episodes of atrial fibrillation is asymptomatic. Methods: The study included 174 consecutive outpatient cases with heart failure, sinus rhythm and implanted Cardioverter Defibrillator and Cardiac Resynchronisation Therapy with Defibrillator. Control visits with analysis intracardiac electrograms records occurred every three months. Each AF episode stored in the device’s memory lasting at least 30 seconds was considered an episode of atrial fibrillation. A symptomatic episode was considered when arrhythmia led to ICD shock, heart deterioration, collapse or fainting, palpitations, weakness, chest pain or shortness of breath accompanied by a feeling of irregular heartbeat. During mean follow-up of 20 months, 901 visits were carried out. 147 patients had at least one year of follow-up. Results: Atrial fibrillation (AF) episodes in the study occurred in 54 (31.0%) patients. Of the 241 atrial fibrillation episodes recorded in the device’s memory, 71.4% were asymptomatic. There was no statistically significant difference in the incidence of new episodes of atrial fibrillation (P = 0.384) in the study group with a history of stroke or transient ischemic episodes during follow-up. However, asymptomatic AF episodes were more common in stroke patients (P = 0.0074). In the time of observation in the whole group of patients there were no new strokes and transient ischemic attack. Conclusion: In conclusion, detection of asymptomatic atrial fibrillation episodes based on intracardiac electrocardiogram records is effective method. In the study group, such episodes were up 71.4% of all newly detected AF episodes.

Subclinical Atrial Fibrillation and Risk of Stroke: Past, Present and Future.

Subclinical atrial fibrillation (SCAF) describes asymptomatic episodes of atrial fibrillation (AF) that are detected by cardiac implantable electronic devices (CIED). The increased utilization of CIEDs renders our understanding of SCAF important to clinical practice. Furthermore, 20% of AF present initially as a stroke event and prolonged cardiac monitoring of stroke patients is likely to uncover a significant prevalence of SCAF. New evidence has shown that implanting cardiac monitors into patients with no history of atrial fibrillation but with risk factors for stroke will yield an incidence of SCAF approaching 30–40% at around three years. Atrial high rate episodes lasting longer than five minutes are likely to represent SCAF. SCAF has been associated with an increased risk of stroke that is particularly significant when episodes of SCAF are greater than 23 h in duration. Longer episodes of SCAF are incrementally more likely to progress to episodes of SCAF >23 h as time progresses. While only around 30–40% of SCAF events are temporally related to stroke events, the presence of SCAF likely represents an important risk marker for stroke. Ongoing trials of anticoagulation in patients with SCAF durations less than 24 h will inform clinical practice and are highly anticipated. Further studies are needed to clarify the association between SCAF and clinical outcomes as well as the factors that modify this association.

Sequential approach for the detection of atrial fibrillation in patients with cryptogenic stroke

Introduction and objectivesParoxysmal and asymptomatic episodes of atrial fibrillation (AF) can be the cause of previously diagnosed cryptogenic stroke. Guidelines recommend monitoring in this setting, although the optimum duration and method remains unknown. We aimed to determine the diagnostic yield of a sequential monitoring approach using external and internal loop recorders for detecting AF in patients with cryptogenic stroke after a complete diagnostic evaluation. MethodsA total of 119 patients were enrolled. A 24-h Holter was performed in all patients. An ambulatory external loop recorder was scheduled in patients without evidence of AF on Holter, followed by ambulatory internal loop recorder implantation in cases without evidence of AF at this point. ResultsAF was identified in 43 of 119 patients (36%). The rate of detection was 15.1% at 6 months, 24.3% at 12 months, 35.3% at 24 months, and 36.1% at 36 months. AF was detected in 21/112 patients (18.75%) with the external loop recorder, and in 17/80 (21%) with internal loop recorder. ConclusionsA standardized sequential monitoring strategy in patients in whom an embolic source is suspected detects AF frequently, allowing a reduction in insertable loop recorder implantation as in 60% of cases AF is detected using non-invasive methods.

Subclinical atrial fibrillation - what is the risk of stroke?

Atrial fibrillation is the most common arrhythmia and as such, it has become a significant public health issue due to its impact on patient morbidity and mortality. The prevalence of atrial fibrillation (AF) almost doubled in the last decade, being currently 2% in unselected patient populations. Its occurrence varies with age (present in almost 20% of octogenarians) and concomitant diseases. The most prevalent concomitant diseases are hypertension, diabetes, heart failure, renal failure, and cognitive decline. Cognitive decline or stroke may be actually the first manifestation of undiagnosed atrial fibrillation. In the majority of cases, atrial fibrillation is more of a syndrome than a disease in itself, with a multitude of etiologic factors and mechanisms. The risk of cardioembolic stroke increases with the number of comorbidities and age. The overall age-adjusted risk of stroke in patients with atrial fibrillation is 5 times higher than in the general population. Nowadays, the detection of asymptomatic episodes of atrial fibrillation by cardiac electronic implantable devices (CIED), referred to as device detected or subclinical atrial fibrillation, has opened new frontiers in AF management. The risk of stroke and subsequent need for anticoagulation treatment in this group of patients with device detected AF is however not clear. Here, we will review the literature to determine the association of subclinical atrial fibrillation with the risk of stroke.

Incidence and Predictive Factors of Hidden Atrial Fibrillation Detected by Implantable Loop Recorder After an Embolic Stroke of Undetermined Source.

The term embolic stroke of undetermined source (ESUS) has been defined for patients with ischemic strokes, where neither a cardioembolic nor a non-cardiac source can be detected. These patients may have asymptomatic episodes of atrial fibrillation (AF). Prolonged monitoring with implantable loop recorder (ILR) and daily remote interrogation in patients after an ESUS has shown an incidence of AF of about 25%. The main objective of this study was to analyze the incidence and predictive factors of atrial fibrillation in patients with ESUS who underwent an ILR implantation. It was a single center study. From June 2013 to January 2017 all consecutive patients with an ESUS, who underwent an ILR implantation searching for hidden AF, were included. Possible predictive factors of AF were also analyzed. 65 patients were included (mean age 65.4±13.8 years, 55.4% males, mean CHA2DS2VASc score 2.3± 1.5). After a median follow-up of 17.1±10.7 months, AF was detected in 19 (29.2%) of patients. Variables associated with AF were: age > 65 years (HR 9.45 (CI 95% 1.25-71.34); p= 0.02), CHA2DS2VASC score≥2 (HR 4.09 (CI 95% 0.93-17.87); p=0,06), left atrial enlargement (HR 2.29 (CI 95% 0.89-5.91); p=0.08) and presence of Supraventricular premature complex(SVC) on 24-hour Holter (HR 4.05 (CI 95% 1.55-10.57); p = 0.004) A cut-point of 0.15% for SVC was identified to predict AF with a sensitivity and specificity of 88.9 and 90%, respectively. A CHA2DS2VASc score<2 and age<65 years showed a negative predictive value to exclude AF of 91.3% and 96%, respectively. A high incidence of AF was detected in this population. Age >65 years, LA enlargement, CHA2DS2VASC score≥2 and presence of SVC on 24-hour Holter are predictive factors of AF in patients with ESUS.

Effect of dual-chamber minimal ventricular pacing on paroxysmal atrial fibrillation incidence in myotonic dystrophy type 1 patients: A prospective, randomized, single-blind, crossover study

Atrial fibrillation (AF) is a common finding in the myotonic dystrophy type 1 (DM1) population. Pacemakers (PMs) may facilitate the diagnosis and management of frequent subclinical asymptomatic AF episodes. The purpose of this study was to evaluate the effect of minimal ventricular pacing on paroxysmal AF incidence in DM1 patients during a 24-month follow-up period. We enrolled 70 DM1 patients (age 43.4 ± 13.8 years; 39 women) who underwent dual-chamber PM implantation. Patients were randomized to minimizing ventricular pacing features (ON) or not (OFF). Patients crossed over to the opposite pacing programming 12 months later. We counted the number of DM1 patients with at least 1 episode of AF, the AF total duration, and the burden recorded by PM diagnostics during the MVP ON and OFF phases. Twenty-five DM1 patients (41.7%) showed at least 1 AF episode. Seven patients (11.7%) demonstrated AF episodes during MVP ON phase and 25 patients (41.7%) during MVP OFF phase (P<.001). Thirty-five patients had no AF during MVP ON or OFF phase, 3 patients had AF episodes only during MVP ON phase, 21 patients had AF episodes only during MVP OFF phase, and 4 patients had AF episodes during MVP ON and OFF phases. Activation of the MVP algorithm was associated with a 44% reduction in relative risk of developing AF. Furthermore, during the MVP ON phases, the study population showed a shorter total AF duration and a lower AF burden. MVP is an efficacy strategy for reducing the risk of AF in DM1 patients who have undergone PM implantation.

Occurrence and Natural History of Clinically Silent Episodes of Atrial Fibrillation in Hypertrophic Cardiomyopathy

Overt symptomatic atrial fibrillation (AF) occurs in over 20% of patients with hypertrophic cardiomyopathy (HC) leading to impaired quality of life, loss of productivity, and the risk for embolic stroke. However, the overall burden presented by AF in the HC population is unresolved due to the unknown frequency of silent asymptomatic episodes that do not necessarily achieve clinical recognition but nevertheless may have important disease-related implications. Therefore, stored electrograms were analyzed retrospectively for AF in 75 consecutive patients with HC (without AF history) implanted with dual-chamber cardioverter-defibrillators. Patients were followed for 5.0 ± 4.1years at the Tufts Medical Center HCM Institute; ages were 50 ± 15years, and 55% were male. Implantable cardioverter-defibrillator interrogation in the 75 patients showed AF to be absent in 54 (72%), 18 (24%) had clinically silent AF episodes, and the remaining 3 (4%) without previous asymptomatic episodes developed symptomatic and clinically overt paroxysmal AF. Of the 18 patients with clinically silent AF, 8 developed symptomatic AF, 4.1 ± 1.5years later. Nonfatal embolic stroke occurred in 1 patient associated with asymptomatic AF and without other risk factors. In conclusion, clinically silent AF appears to be common in HC, occurring in almost 25% of patients. Such asymptomatic episodes of AF have important future implications, including potential thromboembolic risk, and development of symptomatic and clinically overt AF requiring prophylactic anticoagulation.

Anticoagulation Management in Patients with Pacemaker-Detected Atrial Fibrillation.

INTRODUCTION:In patients with an implanted pacemaker, asymptomatic atrial fibrillation (AF) is associated with an increased risk of thrombo-embolic complications. There is still no consensus which duration of episodes of atrial fibrillation should be taken as an indicator for inclusion of oral anticoagulation therapy (OAC).MATERIAL AND METHODS:A total of 104 patients who had no AF episodes in the past and have an indication for permanent pacing were included in the study.RESULTS:During an average follow-up of 18 months, 33 of the patients developed episodes of AF. Inclusion of OAC was performed in 17 patients, in whom AF was recorded, although in all patients CHA2DS2-VASc score was ≥ 1. The inclusion of OAC showed a statistically significant correlation with increasing duration of episodes of AF (r = 0.502, p = 0.003). During the follow-up period none of the patients developed thrombo-embolic complication.CONCLUSION:Considering that our group of patients had no thrombo-embolic events, we could conclude that dividing the AF episodes in less than 1% in 24 hours and longer than 1% within 24 hours could be an indicator for decision-making to include OAK if the CHA2DS2-VASc score is ≥ 1.

Stroke and Systemic Embolism After Successful Ablation of Typical Atrial Flutter.

Following successful cavotricuspid isthmus (CTI) ablation during typical atrial flutter (AFL), anticoagulation therapy is usually withdrawn. However, potential subsequent atrial fibrillation (AF) in these patients may increase embolic risk in the long term. Embolic rates in this setting have not been clearly established. Our aim was to determine the incidence of stroke/systemic embolism following radiofrequency ablation of AFL, particularly in those without a prior history of AF. After succesful AFL ablation, patients may suffer embolic complications in the long-term follow-up, mainly due to asymptomatic AF episodes. We conducted a retrospective analysis of all patients who underwent CTI ablation due to AFL in our center between 2006 and 2009. During the study period, 188 patients (mean age, 62.9 ± 8.6 years) underwent CTI ablation; 120 without prior AF were included in the study. At the end of the follow-up period (mean, 5.0 ± 2.4 years), 56.7% of patients (68/120) remained in sinus rhythm, 7/120 experienced a recurrence of AFL, and 45/120 (38%) developed AF. Ischemic stroke occurred in 11 patients and systemic embolism in 1. Of these patients, 5 had documented AF following AFL ablation. In the remaining 7 cases, previously undiagnosed AF was subsequently diagnosed at the time of stroke/embolism. Patients with AFL who undergo successful ablation are by no means free from embolic complications during long-term follow-up, mainly due to a high rate of AF development. Given the difficulties in detecting AF and the uncertainty about the temporal relation of AF and stroke, oral anticoagulation may need to be continued in those patients with underlying stroke risk factors.