Future Development Of Atrial Fibrillation Research Articles

P3772Risk factors for future development of atrial fibrillation are not evident among apparently healthy individuals with paroxysmal atrial fibrillation

Abstract Background Atrial fibrillation (AF) is one of the important factors of cardiovascular morbidity and mortality and to find not only patients with persistent AF but also individuals with paroxysmal AF among apparently healthy people is a crucial strategy for decreasing number of patients with serious cardio-embolic stroke. However, screening ability using previously known risk factors for future development of AF has not been examined in individuals with paroxysmal AF. Methods A total of 59730 male individuals, aged 40 years or older who underwent multiple comprehensive physical check-ups including 12 lead electrocardiogram (ECG) from 2012 to 2015 were enrolled. Persistent AF was defined a case that consecutively manifested AF till the last checkup. Paroxysmal AF was defined as a case who transiently manifested AF in each of the checkup and subsequently manifested sinus rhythm at the last checkup. Non-AF was defined as a case that never manifested AF in any of checkup. Age-adjusted prevalence rates and their 95% confidence intervals of known-risk factors in the first survey were estimated by logistic regression analysis separately by the three groups (non-AF (n=58602), paroxysmal AF (n=392) and persistent AF (736)). Results Age-adjusted prevalence rates (95% confidence interval) of risks factors for AF are shown in the table. Already known risk factors were evidently manifested in persistent AF group, however, prevalence rates of these factors in paroxysmal AF group were not different from the rates in non-AF group. Conclusion The repeated measurements of ECG study indicated that individuals who would develop paroxysmal AF in the near future did not have typical risk factors for AF and a screening test using risk factors for AF have no chance to find a high-risk individual for paroxysmal AF.

Atrial electromechanical duration prolongs in patients with erectile dysfunction

Background: It is well known that erectile dysfunction (ED) is associated with increased risk of atrial fibrillation (AF) development. On the other hand, prolongation of the duration of atrial electromechanical delay (AEMD) is known to be a precursor for AF development. We aimed to evaluate AEMD in patients with ED patients without documented AF.Methods: Total of 68 outpatients with previously documented vascular ED and 44 participants without ED were enrolled to the current study. Sixty-eight patients with ED called as ED group and 44 participants without ED served as control group. We performed International Index of Erectile Function (IIEF-5) questionnaire for all participants to determine the disease severity of ED groups and to diagnose ED in control groups. Patients with a IIEF-5 score ≥22 were defined as having normal erectile functions. Both intra- and inter-AEMD were measured with tissue Doppler imaging. P-wave dispersion (PWD) was measured on a 12-lead electrocardiogram.Results: Basal characteristics were similar between the two groups. PWD, inter- and right intra-AEMD were significantly prolonged in patients with ED, compared to the control group (p = .02, p < .001 and p < .001, respectively). In the correlation analysis, IIEF-5 score was significantly negative correlated with systolic blood pressure, right intra- and inter-AEMD (r = –0.37, p = .02; r= −0.27, p = .02; r = –0.39, p = .001, respectively).Conclusions: According to current study results, AEMD is significantly correlated with ED severity and may be useful to stratify ED patients to the high-risk group for future development of AF as a cheap and easy method.

Electrocardiographic evidence of abnormal atrial phenotype in Brugada syndrome

BackgroundBrugada syndrome (BrS) is an inherited ion channelopathy that may predispose affected individuals to atrial cardiomyopathy. We tested the hypothesis that BrS patients have higher degrees of atrial electrophysiological abnormalities compared to controls, and these can be reflected by changes in P-wave parameters determined on the electrocardiogram (ECG). MethodsThis was a single-center retrospective study comparing BrS patients to age- and gender-matched control subjects. Mean P-wave duration (PWDmean), maximum PWD (PWDmax) and minimum PWD (PWDmin), P-wave dispersion (PWDmax – PWDmin), and P-wave terminal force in V1 (PTFV1) were measured. PWDmax ≥ 120 ms, in the presence and absence of biphasic P-waves in the inferior leads, were termed advanced and partial inter-atrial block (IAB), respectively. ResultsThe proportion of IAB was significantly higher in BrS patients (28/51; 55%) than in control subjects (14/51; 27%; Fisher's Exact test; P < 0.01). Advanced IAB was observed in two BrS patients but none of the control subjects (P = 0.50). Compared to controls, BrS patients showed higher PWDmean (107 [98–113] vs. 97 [90–108] ms; KWANOVA, P < 0.01), PWDmax (123 [110–132] vs. 113 [107–121] ms; P < 0.001) but statistically indistinguishable PWDmin (82 [72–92] vs. 77 [69–85]; P = 0.09), and P-wave dispersion (38 [26–52] vs. 37 [23–45] ms; P = 0.14). PTFV1 was significantly higher in BrS patients than in control subjects (24 [0–40] vs. 0 [0–27] mm.ms; P < 0.05). ConclusionAtrial conduction abnormalities are frequently observed in BrS. These patients may require monitoring for future development of atrial fibrillation and stroke.

Clinical Impact of Oral Anticoagulation in Patients with Atrial High-rate Episodes

Background: Atrial high-rate episodes (AHREs) are common in pacemaker patients. Our aims were to compare patients with AHREs to those without them and to assess if, in those with AHREs, the initiation of oral anticoagulation (OAC) has any clinical impact on the occurrence of ischemic and hemorrhagic events. Methods: From 2014-2017 we selected patients with pacemaker in whom AHREs were detected. AHREs were defined as episodes lasting more than 6 minutes if the electrogram was available or more than 6 hours if not. We used an age- and gender-matched population with pacemaker but no AHRE as a control group (observational study). Those with AHRE were referred to their assistant physician to decide OAC initiation, based on individual circumstances (interventional study). In interventional study, the primary outcome was a composite of systemic thromboembolism or major bleeding. Secondary outcomes were clinical relevant nonmajor bleeding, major and nonmajor bleeding, CV death, and death from all causes. Results: AHREs were detected in 86 patients: 69 patients initiated OAC and the remaining 17 patients did not. When comparing patients with and without AHRE, baseline characteristics were not different between the groups, except for indexed left atrium volume—40 mL (IQR: 34-50) in AHRE group versus 35 mL (IQR: 34-40) in control group (P = .014). AHREs were associated with future development of atrial fibrillation (AF) and the risk was higher if AHRE duration was superior to 6 hours. Death and cardiovascular (CV) death were not significantly different between the groups with and without AHRE. Primary outcome occurred in 4.9 per 100 person-year in OAC group versus 3.4 per 100 person-year in non-OAC group (HR 1.4, 95% CI .2-11.3, P = .78). Secondary outcomes were not significantly different in the groups. Conclusions: In this group of patients with pacemakers, the presence of AHREs was useful for predicting the future development of AF and the risk of AF was higher in those with a longer duration of AHRE. In the AHRE group, OAC therapy was not associated with a significant difference in the risk of thromboembolism or major bleeding.

P1216Electrical dysfunction precedes atrial dilation in left atrial hypertension and predicts future development of atrial fibrillation

P1216Electrical dysfunction precedes atrial dilation in left atrial hypertension and predicts future development of atrial fibrillation

Impact of long-term glycemic variability on development of atrial fibrillation in type 2 diabetic patients.

Objective:It is well known that patients with type 2 diabetes mellitus (T2DM) have a high risk of atrial fibrillation (AF). The current study was designed to determine the relationship between long-term glycemic variability and incidence of new-onset AF in T2DM patients.Methods:Between January 2008 and December 2009, we conducted a retrospective cohort study in patients with T2DM referred to our hospital. In 505 consecutive patients without any medical history of AF at baseline, the relationship between hemoglobin A1c (HbA1c) variability and future AF incidence was evaluated, with adjustments for other possible confounding factors. HbA1c variability was determined by standard deviation (SD) and coefficient of variation (CV).Results:Over a median of 6.9-year follow-up period, 48 patients (9.5%) developed incident AF. Multiple cox regression revealed that higher HbA1c-SD (HR: 1.726, 95% CI: 1.104–1.830, p=0.001) or HbA1c-CV (HR: 1.241, 95% CI: 1.029–1.497, p=0.024) remained the remarkable predictor of new-onset AF after adjusting for age, body mass index, left ventricular mass index, and left atrium diameter. Receiver operating curve analysis identified thresholds for HbA1c-SD (0.665%, sensitivity 71.4%, specificity 54.9%) and HbA1c-CV (8.970%, sensitivity 73.8%, specificity 47.1%) to detect new-onset AF development.Conclusion:In patients with T2DM, higher HbA1c variability is significantly associated with future AF development.

Association between Heat Shock Protein-60 and Development of Atrial Fibrillation: Results from the Multi-Ethnic Study of Atherosclerosis (MESA).

During atrial fibrillation (AF), a high rate of myocyte activation causes cellular stress and initiates the process of atrial remodeling, which further promotes persistence of AF. Although heat shock proteins (HSPs) have been shown to prevent atrial remodeling and suppress the occurrence of AF in cellular and animal experimental models, increased levels of HSP-60 have been observed in patients with postoperative AF, likely reflecting a response to cellular stress. To better understand the role of HSP-60 in relation to AF, we examined the association of HSP-60 levels in relation to the future development of AF in the Multi-Ethnic Study of Atherosclerosis (MESA). MESA is a cohort study that recruited 6,814 participants aged 45-84 years and free of known cardiovascular disease at baseline (2000-2002) from six field centers. We investigated 983 participants, selected at random from the total cohort, who had HSP-60 measured and were free of AF at baseline. We tested the association of HSP-60 levels with the incidence of AF using multivariate Cox models after adjustment for demographics, clinical characteristics, and biomarkers. During an average of 10.6 years of follow-up, 77 participants developed AF. We did not observe a significant association between the log-transformed HSP-60 levels and development of AF on either unadjusted or multivariate analysis (adjusted hazard ratio: 1.02 per unit difference on natural log scale, 95% confidence interval: 0.77-1.34 ln (ng/mL). Contrary to the findings from the preclinical studies, which demonstrated an important role of HSP-60 in the pathogenesis of AF, we did not observe a significant association between HSP-60 and occurrence of AF.

Abstract 12471: CHA 2 DS 2 VASc Score Predicts Future Development of Atrial Fibrillation After Successful Catheter Ablation of Typical Atrial–Flutter

Introduction: After successful catheter ablation (CA) for typical atrial flutter (AFL), long term development of atrial fibrillation (AF) is common. No definitive predictive models currently exist to identify patients who are likely to develop AF. The aim of this study was to evaluate whether CHA 2 DS 2 VASc score can predict future occurrence of AF after successful CA of AFL. Methods: We conducted a retrospective chart review of 171 consecutive patients with isolated AFL who underwent successful CA between years 2007-2014 at a teaching community hospital. Patients with at least 2 years of follow-up were included for analysis. 40 patients were lost to follow-up. CHA 2 DS 2 VASc scores were calculated at the time of CA. Follow up consisted of in-office electrocardiograms, and (when available) in-office and remote device interrogation. Patients were anticoagulated at the discretion of their treating physician. The endpoint was time to first occurrence of AF. Data was analyzed using appropriate descriptive and univariate statistics to describe, compare and contrast based upon AF occurrence groups. A cox regression was performed to examine CHA 2 DS 2 VASc score as a predictor of AF occurrence during CA follow-up. Results: 131 patients were included in the study. Average age was 66 ±11.5 years and follow-up duration was 26.6±1.5 months. AF occurred in 52 patients (39.7%) by 2 years. Patients who developed AF had a CHA 2 DS 2 VASc score of 3.4±1.4, compared to 2.6±1.3 for patients who did not (p &lt; 0.003). Patients who developed AF were also older (70.2±10.3 vs. 63.7±11.6 years, p&lt;.001,), and had a higher rate of Hypertension (3.40±1.35 vs. 2.6±1.3, p=.037,). CHA 2 DS 2 VASc score was found to be significantly associated with AF onset during the 2 year follow-up (p&lt;.007, Hazard Ratio 1.36, 95%CI 1.09-1.70). Conclusion: The incidence of AF following CA of AFL is common. CHA 2 DS 2 VASc score may be a useful tool and predictor of AF after typical AFL ablation. This needs to be evaluated further in larger randomized trials which may help in guiding long term anticoagulation therapy.

Predictors of Future Atrial Fibrillation Development in Patients with Hypertrophic Cardiomyopathy: A Prospective Follow‐Up Study

We evaluated whether left atrial (LA) phasic functions, P-wave dispersion (PWD), and plasma NT-proBNP levels could predict future development of atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM). Seventy patients with HCM were evaluated. The LA phasic functions including the LA total emptying volume (LATEV), LA total emptying fraction (LATEF), LA active emptying volume (LAAEV), LA active emptying fraction (LAAEF), LA passive emptying volume (LAPEV), and LA passive emptying fraction (LAPEF) were evaluated. P-wave dispersion was calculated. Plasma NT-proBNP levels were measured on the same day with echocardiographic study. Patients were followed up 53.09 ± 1.87 months. Patients who developed AF (n = 18) had significantly higher PWD values, NT-proBNP levels, LAVI, E/E' av, and resting LVOT gradients and significantly lower LATEF and LAAEF. In multivariate analysis, LATEF (P = 0.002), LAAEF (P = 0.007), logNT-proBNP level (P = 0.022), and PWD (P = 0.018) were associated with AF development. The results of receiver operating characteristic analysis revealed that a LATEF cutoff value 49% with 72% sensitivity and 81% specificity, a LAAEF cutoff value of 36% with 72% sensitivity and 71% specificity, and an NT-proBNP cutoff value of 720 pg/mL predicted future AF development with 72% sensitivity and 60% specificity. A PWD cutoff value of 47.5 msecond predicted future AF development with 78% sensitivity and 72% specificity. In patients with HCM, LA phasic functions, PWD, and NT-proBNP levels predict future development of AF. Assessment of LA phasic functions during routine echocardiographic evaluation and measuring NT-proBNP levels and PWD values of patients with HCM during daily practice may provide important data in predicting those at high risk of AF occurrence.

Red blood cell distribution width and atrial fibrillation in patients with sick sinus syndrome

BackgroundSick sinus syndrome (SSS) is associated with atrial fibrillation (AF). Red blood cell distribution width (RDW) is a marker of anisocytosis of erythrocytes and is related to inflammatory stress. Recently, RDW has been associated with AF. The aim of the present study was to evaluate the potential association of RDW with AF history in patients with SSS. MethodsConsecutive patients with symptomatic SSS undergoing dual-chamber pacemaker implantation were screened. Baseline clinical, laboratory, echocardiographic, and electrocardiographic parameters were recorded. Conventional inflammatory indexes were also assessed. Multivariate logistic regression analysis and receiver operating characteristic (ROC) curve analysis for parameters associated with AF were performed. ResultsThe final study population consisted of 101 patients (47 men); median age: 77 [73–82] years. The demographic and clinical characteristics were comparable between tachy-brady (AF history) patients (n=32) and patients with other forms of SSS (n=69). Left atrial diameter was increased in tachy-brady patients [44 (39–48)mm vs. 39 (36–44)mm; p=0.05]. Also, the RDW was greater in these patients [14.7 (13.6–15.4)% vs. 13.7 (13.4–14.3)%; p=0.02]. Multivariate analysis showed that RDW is independently associated with AF (OR: 1.58; 95% CI: 1.06–2.85; p=0.04). The ROC curve analysis showed that the area under the curve was 0.69 (p=0.028). A RDW cut-off point of 14 was related to AF with a sensitivity of 70% and a specificity of 69%. ConclusionRDW is associated with AF history in patients with SSS. The prognostic value of RDW in terms of future AF development and arrhythmia perpetuation in these patients should be further examined.

Impact of B‐type natriuretic peptide (BNP) on development of atrial fibrillation in people with Type 2 diabetes

To examine if a simple biomarker can identify people with diabetes who are at high risk of atrial fibrillation. A retrospective cohort study was conducted at a single centre in people with Type 2 diabetes referred to our department between January 2000 and December 2007. In 517 consecutive people without any history, signs or symptoms of atrial fibrillation at baseline, the association between baseline B-type natriuretic peptide level and future atrial fibrillation incidence was examined, with adjustments for other potentially confounding factors. A total of 28 people were diagnosed with new-onset atrial fibrillation during a median 6-year follow-up. When people were categorized into three groups according to B-type natriuretic peptide clinical thresholds (20 and 100 pg/ml), hazard ratios for the development of atrial fibrillation in the middle and highest B-type natriuretic peptide groups were 2.8 and 9.4, respectively, compared with the lowest B-type natriuretic peptide group. Time-dependent receiver-operating curve analysis identified a threshold for B-type natriuretic peptide to detect atrial fibrillation development of 52.8 pg/ml (sensitivity 75.2%, specificity 68.8%). The B-type natriuretic peptide predictive value was independent of and similar to that of left atrial size and ventricular dimension. In people with Type 2 diabetes, high baseline B-type natriuretic peptide levels were significantly associated with future atrial fibrillation development.

Prognostic value of atrial fibrillation inducibility after right atrial flutter ablation.

Patients with typical right atrial flutter (AFL) may also have underlying atrial fibrillation (AF) or be at high risk of developing AF. Inducibility of AF among patients undergoing AFL ablation may be an important predictor of future occurrence of AF and may be useful in guiding management of this patient population. This study aimed to determine whether inducibility of AF at the time of AFL ablation is independently associated with the risk of future AF. Attempt at induction of AF by burst pacing was performed in consecutive patients who underwent AFL ablation. Time to incidence of AF after AFL ablation was examined using multivariable Cox proportional hazards models. All analyses were stratified by a history of AF. A total of 175 patients were retrospectively evaluated over a median follow-up period of 482 days. In patients without a documented history of AF (n = 93), the incidence of AF after AFL ablation was 18.7 per 100 person-years. In these patients, inducible AF was strongly associated with the future development of AF (adjusted hazard ratio 15.99; 95% confidence interval 5.10-50.12). In contrast, in patients with a documented history of AF (n = 82), the incidence of AF after AFL ablation was 59.3 per 100 person-years and inducible AF was not associated with the future development of AF (adjusted hazard ratio 1.26; 95% confidence interval 0.74-2.14). Inducibility of AF after AFL ablation is strongly and independently associated with the risk of future AF among patients without a history of AF but not among patients with a history of AF.

Left Atrial Remodeling in Hypertrophic Cardiomyopathy and Susceptibility Markers for Atrial Fibrillation Identified by Cardiovascular Magnetic Resonance

In hypertrophic cardiomyopathy (HC), atrial fibrillation (AF) is an important determinant of clinical deterioration due to heart failure or embolic stroke. This study characterizes left atrial (LA) structural and functional parameters to establish markers predictive of AF risk, using cardiovascular magnetic resonance (CMR) imaging. We studied 427 consecutive patients with HC in sinus rhythm with CMR (age 44±18 years), including 41 who developed clinically overt AF after study entry (2.6±2.1 years), 49 patients with AF before CMR, 337 patients with HC but without AF, and 244 normal controls. LA chamber was assessed for absolute and indexed end-diastolic volume (LAEDV), end-systolic volume, and percent ejection fraction (LAEF). In the 41 prospectively studied patients with HC who developed AF during follow-up, LAEDV was significantly greater than in patients without AF (146±48 vs 107±37 ml) or in normal controls (81±24 ml, p<0.001). Percent LAEF was lower in patients developing AF (36±10%) than without AF (46±12%) or controls (55±9%, p<0.001). Multivariate analysis identified LAEF (<38%), LAEDV (≥118 ml), and age (≥40 years) as independently associated with AF occurrence. In conclusion, CMR measures of LA remodeling and dysfunction reliably identified patients with HC at risk for future development of AF. Decrease in LAEF represents a strong novel marker of susceptibility to AF in this disease.

Hypertension accelerates the ‘normal’ aging process with a premature increase in left atrial volume

Hypertension (HT) is associated with left ventricular (LV) diastolic dysfunction and consequent left atrial (LA) dilatation. We investigated changes in LA size and phasic function by decade in patients with HT. Patients with mild or moderate HT (n = 122) were compared with a case controlled normal cohort (blood pressure <140/90 mm Hg). Biplane LA maximum, minimum, and pre ‘a’ wave volumes were measured; LA filling, passive emptying, and active emptying volumes and fractions were calculated. Transmitral inflow and pulsed wave mitral annular tissue Doppler velocity were measured as expressions of LV diastolic function. The HT group had larger LA maximum volumes compared with normal controls for all decades until the 8th decade. Subjects with HT in decade 4 had LA maximum volume similar to that of normal controls from decade 8 (27.8 ± 4.3 mL/m2 vs 25.6 ± 6.1 mL/m2 respectively, P = .22). Active emptying volume and fraction were higher in the HT group across all decades, while there was no difference between the HT and normal groups for passive emptying volume. LV mass and E/E′ ratio were significantly higher across all decades in the HT group. HT alters atrial dynamics significantly, with resultant increased LA volume and active emptying volume consequent to altered LV diastolic function. HT ‘accelerates’ the normal aging process with patients as early as decade 4 having similar LA size to that of normal controls in decade 8. This premature increase in LA volume may result in the future development of atrial fibrillation in HT patients.

A functional variant in the promoter region regulates the C‐reactive protein gene and is a potential candidate for increased risk of atrial fibrillation

In a large population-based cohort, the level of C-reactive protein (CRP) in patients at baseline predicts an increased risk of future development of atrial fibrillation (AF). The mechanism of this increased risk is unknown. Furthermore, both the molecular effects of CRP on atrial myocytes and fibroblasts and whether genetic variants in the CRP gene predispose to AF are also unknown. A genetic association study between CRP gene polymorphisms and AF was performed in two independent populations (I: 100 AF patients and 101 controls; II: 348 AF patients and 356 controls), with functional studies to elucidate the mechanism of association. Three polymorphisms (T-861C, A-821G and C-390A/C-390T) were found in the 1-kb promoter of CRP. A triallelic polymorphism (C-390A/C-390T) captured all haplotype information and determined the CRP gene promoter activity and the plasma CRP level, and was in nearly complete linkage disequilibrium with G1059C polymorphism in exon 2. The -390A variant was associated with a higher CRP gene promoter activity, a higher plasma CRP level and a higher risk of AF. Patients with AF also had a higher plasma CRP level than controls. CRP significantly increased the inward L-type calcium current in atrial myocytes with no changes in other ionic currents. CRP did not affect the expressions of type I alpha 1 (COL1A1), type III alpha 1 (COL3A1) and type 1 alpha 2 (COL1A2) procollagens in atrial fibroblasts. A CRP gene promoter triallelic polymorphism was associated with CRP gene promoter activity, determined the plasma level of CRP, and predicted the risk of AF. The mechanism of this may be via augmention of calcium influx by CRP in atrial myocytes, but not because of atrial fibrosis.

Herpes simplex virus infection and risk of atrial fibrillation: A nationwide study

BackgroundCurrently, precise mechanisms of atrial fibrillation (AF) are uncertain but proved to be associated with inflammation. There has been no specific study to evaluate the risk of AF after diagnosis of herpes simplex virus (HSV) infection. MethodsTo investigate the relationship between HSV infection and the occurrence of AF, we used a nation-wide population-based dataset from Taiwan. A total of 15,180 patients with diagnosis of HSV infection were included in the study group from a 1,000,000 sampling cohort dataset between January 2000 and December 2003. Another 73,197 age-, gender-, and comorbidity-matched subjects without HSV infection were included in the control group. The log-rank test was performed to analyze the differences in accumulated AF-free survival rates between these 2 groups. Cox proportional hazard regressions were performed to evaluate the independent factor in determining the longitudinal hazard of AF. ResultsDuring a 3-year follow-up period, 240 patients from the study group (1.6%) and 801 patients from the comparison group (1.1%) had newly developed AF. The log-rank test showed that patients with HSV had significantly higher incidence of AF development than those without HSV (p<0.001). After Cox model adjustment for risk factors and comorbidities, HSV infection was independently associated with increased risk of AF development (hazard ratios [HR], 1.39; 95% confidence interval [CI], 1.2–1.60; p<0.0001). ConclusionOur study concludes that HSV infection may be independently associated with an increased risk of future AF development.

Response to Letter Regarding Article, “Birth Weight Is a Significant Risk Factor for Incident Atrial Fibrillation”

We highly appreciate Dr Ashrani's interest in our article.1 We agree that birth length may be a significant marker for future development of atrial fibrillation, and that a direct comparison of birth length with birth weight would be an interesting extension of our study. Unfortunately, birth length is not …

Assessment of atrial electromechanical delay and influential factors in patients with obstructive sleep apnea

The interaction between moderate-to-severe obstructive sleep apnea (OSA) and cardiac arrhythmias, especially atrial fibrillation (AF), is well known. We aimed to determine whether atrial electromechanical parameters assessed by tissue Doppler imaging (TDI) would be affected in moderate-to-severe OSA, and detect the influential factors of atrial electromechanical parameters in these patients. Interatrial and intra-atrial electromechanical delay was measured by TDI in patients with moderate-to-severe OSA (n = 64) and control subjects (n = 39). P-wave dispersion (PWD) was calculated on the 12-lead ECG. Interatrial and intra-atrial electromechanical delay was significantly higher in the OSA group when compared with the controls (52.26 ± 12.9 vs 29.61 ± 11.26, P < 0.0001 and 18.90 ± 8.13 vs 8.71 ± 5.46, P < 0.0001; respectively). PWD was higher in the OSA group (46.09 ± 13.40 ms vs 34.10 ± 10.75 ms, P < 0.0001). Interatrial electromechanical delay had a positive correlation with PWD (r = 0.490, P < 0.0001), left atrial (LA) diameter (r = 0.383, P = 0.002), LA volume index (r = 0.354, P = 0.004), and apnea-hypopnea index (r = 0.365, P = 0.003). In addition, interatrial electromechanical delay was negatively correlated with the magnitude of the lowest oxygen saturation percentage (r = -0.498, P < 0.0001). This study showed that interatrial and intra-atrial electromechanical delay and PWD were prolonged in patients with moderate-to-severe OSA. LA dilatation, hypoxemia, and the severity of the disease may contribute a prolongation in interatrial electromechanical delay via atrial structural and electrical alterations, which may predict the risk of future AF development in patients with moderate-to-severe OSA.

The role of obesity and sleep apnea in atrial fibrillation

To discuss the relationship between obesity and obstructive sleep apnea as they relate to the growing atrial fibrillation epidemic, and to discuss possible mechanistic links and implications for treatment of atrial fibrillation. Increasing BMI plays an important role in development of atrial fibrillation in both men and women. Sleep-disordered breathing contributes to cardiac chamber enlargement, which may be responsible for increasing atrial fibrillation in this population. Patients with obstructive sleep apnea and/or obesity have less freedom from atrial fibrillation recurrence after catheter ablation for atrial fibrillation. BMI is a strong predictor of future development of atrial fibrillation and should be considered as a risk factor for atrial fibrillation. Patients with obstructive sleep apnea and/or obesity have high atrial fibrillation recurrence rates following atrial fibrillation ablation.

Left atrial dyssynchrony assessed by strain imaging in predicting future development of atrial fibrillation in patients with heart failure

Background The clinical and echocardiographic parameters associated with the risk of developing new onset atrial fibrillation (AF) in congestive heart failure (CHF) have not been studied comprehensively. We determined if dyssynchronous left atrial (LA) lengthening and contraction predicted future development of new onset AF in patients with CHF. Methods One hundred fifty-eight patients who were admitted for CHF without past or current AF were evaluated. We measured the time to peak velocity and time to peak strain with reference to the QRS complex during ventricular systole (reservoir) and late diastole (atrial contraction) in mid-portion of 4 LA walls. Dyssynchronous atrial lengthening and contraction (atrial dyssynchrony) was defined as the standard deviation of each parameter. Results New onset AF developed in 21 patients (13.3%) after a mean follow-up of 43 ± 15 months. Based on univariate Cox analysis, older age, larger LA dimension and volume index, lower LA fractional shortening, and the presence of atrial dyssynchrony were associated with new onset AF. In multivariate Cox analysis, atrial dyssynchrony based on strain (> 39 ms, HR 10.0, p = 0.003) and LA size (≥ 45 mm, HR 4.3, p = 0.016) were independent predictors of new onset AF in CHF. Conclusions We demonstrated that atrial dyssynchrony based on strain is the strongest univariate and multivariate predictor for new onset AF in hospitalized patients with CHF.