Rate Control In Atrial Fibrillation Research Articles

Digoxin use and risk of mortality in hypertensive patients with atrial fibrillation.

Digoxin is widely used for rate control of atrial fibrillation. However, recent studies have reported conflicting results on the association of digoxin with mortality when used in patients with atrial fibrillation. Moreover, the relationship of digoxin use to mortality in hypertensive patients with atrial fibrillation has not been examined. All-cause mortality was examined in relation to in-treatment digoxin use in 937 hypertensive patients with ECG left ventricular hypertrophy in atrial fibrillation at baseline (n = 134) or who developed atrial fibrillation during follow-up (n = 803), randomly assigned to losartan or atenolol-based treatment, in post-hoc analysis of a substudy of the Losartan Intervention For Endpoint Reduction in hypertension (LIFE) trial. During 4.7 ± 1.1 years of mean follow-up, 167 patients died (17.8%) and 372 (39.7%) were treated with digoxin. In univariate Cox analyses, in-treatment digoxin use, entered as a time-varying covariate, was associated with a 61% higher risk of dying (hazard ratio 1.61, 95% confidence interval 1.18-2.19, P = 0.003). After adjusting for other univariate predictors of death in this population, including age, diabetes, history of ischemic heart disease, stroke, or heart failure, baseline Cornell product, QRS duration, heart rate, serum glucose, creatinine and high-density lipoprotein cholesterol, and a propensity score for digoxin use entered as standard covariates, and for in-treatment heart rate, pulse pressure, and Sokolow-Lyon voltage treated as time-varying covariates, digoxin use was no longer a significant predictor of mortality (hazard ratio 1.04, 95% confidence interval 0.73-1.48, P = 0.839). In hypertensive patients with ECG left ventricular hypertrophy with existing or new atrial fibrillation, digoxin use is not associated with a significantly increased risk of all-cause mortality after adjusting for other independent predictors of death and for the factors associated with the propensity to use digoxin in this population. These findings suggest that factors other than digoxin use may account for the increased mortality found with digoxin use in some studies. .

β-Blockers versus calcium channel blockers for acute rate control of atrial fibrillation with rapid ventricular response: a systematic review.

This is a systematic review of the literature to compare the efficacy of calcium channel blockers to β-blockers for acute rate control of atrial fibrillation with rapid ventricular response in the emergency department setting. PubMed, EMBASE, and the Cochrane Registry were searched. Relative risk (95% confidence interval) was calculated between drugs and methodological quality of included studies was evaluated. Of the 1003 studies yielded by our initial search, two met inclusion criteria and provided sufficient data. These were randomized double-blinded studies (n=92) comparing intravenous diltiazem with intravenous metoprolol. The combined relative risk of acute rate control by diltiazem versus metoprolol was 1.8 (95% confidence interval 1.2-2.6). On the basis of the paucity of available evidence, diltiazem may be more effective than metoprolol in achieving rapid rate control, but high-quality randomized studies are needed.

28 Heart Rate is not Related to Survival in Patients with Heart Failure and Atrial Fibrillation

<h3>Introduction</h3> Atrial fibrillation (AF) is common in patients with chronic heart failure (CHF), and is associated with significant morbidity and mortality. Although there is robust evidence that heart rate is a risk factor in CHF and that reducing elevated heart rates improves survival in patients who are in sinus rhythm, the importance of strict heart rate control in AF is still not clear. This study sought to investigate the influence of resting ventricular rate on survival in CHF, comparing those who are in sinus rhythm to those in AF. <h3>Methods</h3> A total of 1415 CHF patients (mean age 76+-11 years, 36% females, 65% IHD, 41% NYHA II, 44% NYHA III, 14% NYHA IV), of whom 62% (n = 875) were in sinus rhythm and 38% (n = 540) in permanent AF were evaluated from the BIOSTAT-CHF Scotland study. Patients from both in-patient and out-patient settings were included. We analysed the heart rate and rhythm data recorded on a 12 lead ECG at the baseline review. Multivariate Cox proportional hazards models and Kaplan-Meier curves were used to assess the influence of heart rate on survival in CHF patients with AF or sinus rhythm. <h3>Results</h3> During a median per-person follow-up of 1.5 yrs (QIR 0.7–2.2), there were 330 (23%) all-cause deaths. Although Kaplan-Meier survival curves displayed significant differences between the AF and sinus rhythm groups (log-rank test p = 0.014), multivariate Cox survival models showed no significant difference between the 2 groups (hazard ratio [HR]: 0.98, 95% CI: 0.75–1.29; p = 0.9). When assessing the influence of heart rate, multivariate Cox models showed that higher heart rates (per 10 beats/min increments) were associated with worse survival in patients in sinus rhythm (HR: 1.14, 95% CI: 1.03–1.25; p = 0.008), but not for those in AF (HR: 0.98, 95% CI: 0.91–1.07, p = 0.7), for both preserved and reduced ejection fraction heart failure. When separated into two categories (heart rate &lt;80bpm vs. ≥80 bpm), those in sinus rhythm with a heart rate ≥80 bpm had a significantly worse survival than those with a heart rate &lt;80 bpm (HR: 1.57, 95% CI: 1.10–2.23, p = 0.012). <h3>Conclusion</h3> Although higher heart rate was associated with worse survival for CHF patients in sinus rhythm, it does not appear to be associated with survival in those who are in AF. These findings question the value of strict heart rate control in CHF patients with atrial fibrillation, thus necessitating further research in this area.

Dynamics of AV coupling during human atrial fibrillation: role of atrial rate.

The causal relationship between atrial and ventricular activities during human atrial fibrillation (AF) is poorly understood. This study analyzed the effects of an increase in atrial rate on the link between atrial and ventricular activities during AF. Atrial and ventricular time series were determined in 14 patients during the spontaneous acceleration of the atrial rhythm at AF onset. The dynamic relationship between atrial and ventricular activities was quantified in terms of atrioventricular (AV) coupling by AV synchrogram analysis. The technique identified n:m coupling patterns (n atrial beats in m ventricular cycles), quantifying their percentage, maximal length, and conduction ratio (= m/n). Simulations with a difference-equation AV model were performed to correlate the observed dynamics to specific atrial/nodal properties. The atrial rate increase significantly affected AV coupling and ventricular response during AF. The shortening of atrial intervals from 185 ± 32 to 165 ± 24 ms (P < 0.001) determined transitions toward AV patterns with progressively decreasing m/n ratios (from conduction ratio = 0.34 ± 0.09 to 0.29 ± 0.08, P < 0.01), lower occurrence (from percentage of coupled beats = 27.1 ± 8.0 to 21.8 ± 6.9%, P < 0.05), and higher instability (from maximal length = 3.9 ± 1.5 to 2.8 ± 0.7 s, P < 0.01). Advanced levels of AV block and coupling instability at higher atrial rates were associated with increased ventricular interval variability (from 123 ± 52 to 133 ± 55 ms, P < 0.05). AV pattern transitions and coupling instability in patients were predicted, assuming the filtering of high-rate irregular atrial beats by the slow recovery of nodal excitability. These results support the role of atrial rate in determining AV coupling and ventricular response and may have implications for rate control in AF.

DIGOXIN USE IN ATRIAL FIBRILLATION IS ASSOCIATED WITH INCREASED RISK OF MORTALITY: A SYSTEMATIC REVIEW AND META-ANALYSIS OF MORE THAN 200,000 PATIENTS

Digoxin is a commonly used therapy for rate control in atrial fibrillation (AF). However, there have been discrepant findings on the association between digoxin use and risk of increased mortality in AF patients. We performed meta-analysis of cohort and randomized controlled trials to evaluate

Autologous dermal fibroblast injections slow atrioventricular conduction and ventricular rate in atrial fibrillation in swine.

Nonpharmacological ventricular rate control in atrial fibrillation (AF) without producing atrioventricular (AV) block remains a clinical challenge. We investigated the hypothesis that autologous dermal fibroblast (ADF) injection into the AV nodal area would reduce ventricular response during AF without causing AV block. Fourteen pigs underwent electrophysiology study before, immediately, and 28 days after ≈ 200 million cultured ADFs (n = 8) or saline (n = 6) were injected under electroanatomical guidance in the AV nodal area, with continuous 28-day ECG recording. In the ADF group at 28 days postinjection, there were prolongations of PR interval (after versus before: 130 ± 13 versus 113 ± 14 ms, P = 0.04), of AH interval during both sinus rhythm (92 ± 13 versus 76.8 ± 8 ms, P < 0.01) and atrial pacing at 400 ms (102 ± 13 versus 91 ± 9 ms, P < 0.01), and of AV node Wenckebach cycle length (230 ± 19 versus 213 ± 24 ms, P < 0.01), with no changes in the control group. The RR interval during induced AF 28 days after injections was 24% longer in ADF-treated group compared with controls (488 ± 120 versus 386 ± 116 ms, P < 0.001). Histological analysis revealed presence of ADF-labeled cells in the AV nodal area at 28 days. Transient accelerated junctional rhythm during injections, and transient nocturnal Mobitz I AV conduction occurred early postinjection in both groups. Cells survived for 4 weeks and significantly slowed AV conduction and ventricular rate in acutely induced AF. Critically, despite a large number of injections in the AV nodal area and marked effects on AV conduction, AV block did not occur. Further studies are necessary to determine the clinical feasibility and safety of this strategy for ventricular rate control in AF.

Abstract 18172: Rhythm Control with Catheter Ablation Improves Ejection Fraction Compared to Rate Control: A Meta-Analysis of Randomized Controlled Studies

Background: Atrial fibrillation (AF) can exacerbate/worsen heart failure. A randomized study showed that rhythm control with anti-arrhythmic drugs (AADs) is not superior to rate control for heart failure patients who develop AF. However, a recent study revealed catheter ablation can improve the ejection fraction (EF) compared to medical rate control. Hypothesis: We performed a meta-analysis to compare the effect of rhythm control and medical rate control on EF in heart failure patients with AF. Methods: We searched PubMed, Embase, Google Scholar and Cochrane databases for all randomized controlled trials (RCTs) comparing rhythm control versus rate control for AF in heart failure. Primary outcome was change in EF. Random effects model was used to pool and analyze data across the studies. Results: Of a total of 7 RCTs (4 - AADs, 3 - catheter ablation) which compared rhythm control and medical rate control, 4 studies (n=202) reported quantitative data on EF. There was significant heterogeneity between the studies (I2=82%, p &lt;0.001). Compared to rate control, the mean improvement in EF with rhythm control was 5.94% (95% CI 0.63- 11.26, p=0.03). Sub-group analysis revealed catheter ablation improved the EF by 6.67% (95% CI 0.23 -13.11, p=0.04) whereas rhythm control with AADs did not significantly change EF (3.50, -1.76 -8.76). Conclusion: Rhythm control is associated with greater improvement in EF compared to rate control therapy in heart failure patients with AF. Catheter ablation of AF significantly improves the EF in these patients. Further studies are needed to determine if this improvement in EF is associated with decreased morbidity and mortality.

Digoxin and risk of death in adults with atrial fibrillation: the ATRIA-CVRN study.

Digoxin remains commonly used for rate control in atrial fibrillation, but limited data exist supporting this practice and some studies have shown an association with adverse outcomes. We examined the independent association between digoxin and risks of death and hospitalization in adults with incident atrial fibrillation and no heart failure. We performed a retrospective cohort study of 14,787 age, sex, and high-dimensional propensity score-matched adults with incident atrial fibrillation and no previous heart failure or digoxin use in the AnTicoagulation and Risk factors In Atrial fibrillation-Cardiovascular Research Network (ATRIA-CVRN) study within Kaiser Permanente Northern and Southern California. We examined the independent association between newly initiated digoxin and the risks of death and hospitalization using extended Cox regression. During a median 1.17 (interquartile range, 0.49-1.97) years of follow-up among matched patients with atrial fibrillation, incident digoxin use was associated with higher rates of death (8.3 versus 4.9 per 100 person-years; P<0.001) and hospitalization (60.1 versus 37.2 per 100 person-years; P<0.001). Incident digoxin use was independently associated with a 71% higher risk of death (hazard ratio, 1.71; 95% confidence interval, 1.52-1.93) and a 63% higher risk of hospitalization (hazard ratio, 1.63; 95% confidence interval, 1.56-1.71). Results were consistent in subgroups of age and sex and when using intent-to-treat or on-treatment analytic approaches. In adults with atrial fibrillation, digoxin use was independently associated with higher risks of death and hospitalization. Given other available rate control options, digoxin should be used with caution in the management of atrial fibrillation.

Ivabradine for rate control in atrial fibrillation

Ivabradine for rate control in atrial fibrillation

Role of digoxin in controlling the ventricular rate during atrial fibrillation: a systematic review and a rethinking

Role of digoxin in controlling the ventricular rate during atrial fibrillation: a systematic review and a rethinking Philippe Maury,1 Anne Rollin,1 Michel Galinier,1 Yves Juilli&egrave;re21University Hospital Rangueil, Toulouse, France; 2Institut Lorrain du Coeur de des Vaisseaux Louis Mathieu, Nancy, FranceAbstract: Although digitalis has been used since the last century, it seems to be in the process of being progressively abandoned. However, digoxin has demonstrated a large positive benefit in terms of reduction of morbidity in heart failure patients with sinus rhythm, while the sometimes-observed increase in mortality is dramatically reduced with low serum concentrations. Digoxin, which is the only digitalis currently available, remains one of three drugs used for rate control in atrial fibrillation. Even if digoxin alone is insufficient to provide rate control during exertion in most patients, the optimal cardiac rate both at rest and at exertion is still undetermined, as is the importance of achieving sufficient rate control in asymptomatic patients. Because of its low cost and the accumulated knowledge and expertise about prescription, digoxin probably will remain an undisputed medication for rate control for atrial fibrillation, especially for heart failure patients.Keywords: digitalis, heart failure, atrial fibrillation, heart rate

Avoiding permanent atrial fibrillation: treatment approaches to prevent disease progression

Atrial fibrillation (AF) is the most common sustained arrhythmia and a major global public health problem due to its associated morbidity, including stroke and heart failure, diminished quality of life, and increased mortality. AF often presents initially in a paroxysmal form and may progress to a more sustained form over time. Evidence from randomized controlled trials suggests that there may be no mortality benefit to using a rhythm control approach in comparison with rate control of AF. Nevertheless, sustained forms of AF may be associated with increased symptoms and cardiovascular morbidity, and consequently they remain an additional target for therapy. The present review evaluates the clinical correlates of arrhythmia progression and risk stratification techniques available to assess probability of AF progression. Further, currently available management options for arrhythmia control in AF are evaluated and their therapeutic effect and efficacy on disease progression are explored.

Slowing down the heart rate in permanent atrial fibrillation

This editorial refers to ‘Calcium channel blockers improve exercise capacity and reduce N-terminal Pro-B-type natriuretic peptide levels compared with beta-blockers in patients with permanent atrial fibrillation’, by S.R. Ulimoen et al. doi:10.1093/eurheartj/eht429 Ventricular rate control for atrial fibrillation (AF) is almost as old as the first records of the disease. While digitalis has been the focus of classical observations,1 this substance is currently losing relevance for AF ventricular rate control owing to uncertainties regarding its prognostic value. Recent studies and retrospective analyses of older trials have shed an unfavourable light on digitalis in AF patients, in particular if serum concentrations are elevated.2,3 In general, rate control aims at reducing symptoms and improving exercise capacity. It is recommended as initial treatment for all patients with AF.4 While symptomatic patients with paroxysmal and persistent AF should subsequently undergo further rhythm control actions, patients with permanent AF (as per definition) will remain on rate control medication. Rate control is non-inferior to rhythm control with respect to mortality in patients with different types of AF and with or without heart failure (HF).5,6 Data regarding the impact of rate control on mortality are …

Calcium channel blockers improve exercise capacity and reduce N-terminal Pro-B-type natriuretic peptide levels compared with beta-blockers in patients with permanent atrial fibrillation

Rate control of atrial fibrillation (AF) has become a main treatment modality, but we need more knowledge regarding the different drugs used for this purpose. In this study, we aimed to compare the effect of four common rate-reducing drugs on exercise capacity and levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with permanent AF. We included 60 patients (mean age 71 ± 9 years, 18 women) with permanent AF and normal left ventricular function in a randomized, cross-over, investigator-blind study. Diltiazem 360 mg, verapamil 240 mg, metoprolol 100 mg, and carvedilol 25 mg were administered o.d. for 3 weeks. At baseline and on the last day of each treatment period, the patients underwent a maximal cardiopulmonary exercise test and blood samples were obtained at rest and at peak exercise. The exercise capacity (peak VO2) was significantly lower during treatment with metoprolol and carvedilol compared with baseline (no treatment) or treatment with diltiazem and verapamil (P < 0.001 for all). Compared with baseline, treatment with diltiazem and verapamil significantly reduced the NT-proBNP levels both at rest and at peak exercise, whereas treatment with metoprolol and carvedilol increased the levels (P < 0.05 for all). Rate-reducing treatment with diltiazem or verapamil preserved exercise capacity and reduced levels of NT-proBNP compared with baseline, whereas treatment with metoprolol or carvedilol reduced the exercise capacity and increased levels of NT-proBNP.

Catheter Ablation Versus Rate Control for Atrial Fibrillation: What have We Learnt From the ARC-HF trial?

Catheter Ablation Versus Rate Control for Atrial Fibrillation: What have We Learnt From the ARC-HF trial?

Mortality after atrioventricular nodal radiofrequency catheter ablation in atrial fibrillation: outcomes from a controlled nonrandomized long-term study

Atrioventricular nodal radiofrequency ablation (AVNA) may be recommended for rate control in some patients with atrial fibrillation (AF). However, outcome after AVNA has not been assessed over the long term although it results in pacemaker dependency. Short-term follow-up may not capture the long-term risks of an irreversible procedure. This study investigated the outcome after AVNA, expected to achieve effective rate control and possibly to improve prognosis in AF. Methods: We examined the clinical course of 8,962 consecutive patients with AF seen in the cardiology department of a four-hospital institution between 2000 and 2010. The outcome in 218 patients with AVNA (group 1) was compared with those in other patients (group 2, n=8744). Results: Patients in the 2 groups had same age (71±11 vs 71±15, p=0.60). However, patients in group 1 were sicker than those in group 2 with more frequent heart failure (79% vs 54%, p<0.0001), renal failure (20% vs 9%, p<0.0001), permanent AF (57% vs 39%, p<0.0001), lower left ventricular ejection fraction (42±17 vs 47±16%, p=0.0009), more frequent cardiac resynchronisation therapy (23% vs 2%, p<0.0001) and higher CHA2DS2VASc score (3.5±1.6 vs 3.2±1.8, p=0.02). Death was recorded in 2,023/8,962 patients during follow-up of 934±1134 days. In univariate analysis, patients in group 1 did not have a higher risk of all-cause death than those in group 2 (hazard ratios [HR] = 0.82, 95% confidence interval [CI], 0.63-1.07; p=0.14). Using Cox proportional-hazards model and adjustment on 25 potential confounders, AVNA was associated with a lower risk of mortality (HR=0.59, 95% CI, 0.39-0.88; p=0.01) with younger age (HR=0.36 for age<65, p<0.0001), higher LVEF (HR=1.01 per 1% decrease, p<0.0001), non permanent AF (HR=0.64, p<0.0001), absence of diabetes (HR=0.76, p=0.02), use of beta blockers (HR=0.80, p=0.03), oral anticoagulation (HR=0.56, p<0.0001) and lack of diuretic use (HR=0.72, p=0.004). Conclusions: AVNA needed for rate control in AF (with or without cardiac resynchronisation therapy) was independently associated with a lower mortality in the systematic analysis of a large cohort of AF patients with one of the longest follow-up to date.

Navigating Recently Updated Atrial Fibrillation Clinical Practice Guidelines

Multiple organizations have published clinical practice guidelines that recommend strategies for the management of atrial fibrillation (AF) in the clinic. This article presents various clinical practice recommendations for rate control in AF. Also discussed are the recommendations for antiarrhythmic therapy in AF, recommendations for antithrombotic therapy in AF, tools and techniques used in cryoballoon ablation of pulmonary veins, duty cycled radiofrequency ablation tools and techniques, as well as information about laser ablation.

Rate Control in Atrial Fibrillation: Methods for Assessment, Targets for Ventricular Rate during AF, and Clinical Relevance for Device Therapy.

Rate control is a widely used treatment strategy for management of patients with atrial fibrillation (AF). Multiple studies have shown that pharmacologic rate control is as effective as pharmacologic rhythm control for management of AF. A snapshot ECG or intermittent monitoring using Holters is the most widely used technique for assessing ventricular rate during AF. Patients with implantable devices, such as pacemakers, implantable cardioverter defibrillators, cardiac resynchronization therapy devices, and implantable loop recorders provide the ability for continuous long term monitoring of AF and ventricular rate during AF. It has been shown that continuous monitoring of AF and ventricular rate during AF by implantable devices is the most comprehensive method for assessment of AF occurrence and poor rate control, particularly in patients with paroxysmal and asymptomatic AF. Rapid ventricular rate during AF, as assessed by implantable devices, has been shown to cause reduction in cardiac resynchronization therapy, predict inappropriate defibrillation therapy, and identify increased risk for cardiovascular hospitalizations. The ventricular rate targets for achieving good rate control during AF depend on the patient characteristics with stricter targets recommended for patient with compromised functional capacity, such as patients with HF. Thus it can be hypothesized that timely intervention based on continuous assessment of AF and poor rate control, with ventricular rate targets defined based on cardiovascular disease state, may improve clinical outcomes in patients with AF.

Utility of Mapping Signals to Improve Precision of Atrioventricular Node Ablation

Atrioventricular node (AVN) ablation is effective for rate control in atrial fibrillation. This may require multiple radiofrequency applications to achieve complete atrioventricular block (CAB). In this retrospective study, we tested the hypothesis that mapping the AVN utilizing electrograms (EGMs) on both proximal and distal bipoles of the mapping catheter may improve the likelihood of CAB. Lesion characteristics and EGM components on the proximal and distal bipoles of the ablation catheter in first-time AVN ablation procedures were analyzed. Outcomes of each lesion, including presence of CAB, acute recurrence of AVN conduction, new-onset right bundle branch block (RBBB), and junctional escape rhythm, were analyzed. Multivariate binary logistic regression analysis was performed to identify EGM characteristics that independently predicted the outcomes of interest. Lesions with these EGM characteristics were then identified and their outcomes compared with the whole cohort. A total of 441 ablation lesions were analyzed. EGM characteristics that independently predicted outcomes were the presence of His and atrial EGMs on the distal bipole and the absence of ventricular EGM on the proximal bipole. Among the 25 lesions with all these characteristics, 18 (72%) resulted in CAB compared to the overall cohort rate of 38% (P = 0.001). There was no new-onset RBBB. The likelihood of acute recurrent AVN conduction and junctional escape rhythm were similar. Combining proximal and distal bipole EGM characteristics of the ablation catheter can improve the accuracy of AVN localization during AVN ablation and avoid right bundle branch injury.

Rate control in atrial fibrillation, insight into the RACE II study

Rate control in atrial fibrillation, insight into the RACE II study

Evidenced-Based Pharmacotherapy for Rate Control in Atrial Fibrillation

Atrial fibrillation is the most common arrhythmia found in older adults that places them at a high risk for stroke. The presence of AF in an individual, especially older than 60 years, increases the risk of mortality, affects quality of life, and increases prevalence of heart failure. The goal of AF treatment is to maintain heart rate or rhythm control and stroke prevention through anticoagulation. With appropriate management of AF an improvement of symptoms and a reduced morbidity from stroke or heart failure can be achieved. The best treatment for AF is prevention and early diagnosis.