Onset Atrial Fibrillation In Patients Research Articles

Abstract 18292: Incidence and Recurrence of Atrial Fibrillation in Patients Undergoing Cavotricuspid Isthmus Ablation for Typical Atrial Flutter

Background: A proportion of patients with cavotricuspid dependent right atrial flutter (AFL) have previous episodes of atrial fibrillation (AF). Many patients with isolated AFL (no previous AF) develop AF after AFL ablation. There is limited data evaluating the impact of AFL ablation on the a) development of AF in those without AF and b) recurrence of AF in patients with previous AF. Methods: We performed a retrospective study including all consecutive patients (with or without previous AF) undergoing cavotricuspid isthmus ablation for AFL in a large academic center. Results: A total of 589 patients underwent AFL ablation between 2007 and 2012. Mean age was 64 ±13 years with 74% males. Mean left ventricular ejection fraction was 50 ±14%. Median duration since diagnosis of AFL was 2 months (IQ range 1-10) months. 289 (49%) patients had a history of AF (paroxysmal in 95%) and the remaining 300 (51%) patients did not have AF. Patients “with AF” were on more antiarrhythmics (AADs) prior to ablation when compared to those “without AF”. 67 (23%) patients “with AF” had AF in the lab spontaneously, by programmed stimulation or with isoproterenol infusion when compared to 27 (9%) patients “without AF”; p<0.001. After a mean follow-up time of 31 months, 200 (34%) patients were on AADs (47% vs 12% in patients with and without AF respectively). During follow up, 166 (57%) of the patients “with AF”, had a recurrence of AF and 87 (29%) patients “without AF” developed AF; p<0.001. The independent predictors of AF during follow up in patients with prior AF were CHADS2 score, number of AADs used and AF induction during the procedure. In patients without prior AF, LVEF was the only independent predictor of incident AF Conclusions: At 2.5 years after AFL ablation a) 29% of the patients with isolated AFL develop incident AF and b) 43% of the patients with prior AF do not have AF recurrence. LVEF is the only independent predictor for new onset AF in patients without prior AF.

Aldosterone Antagonists in the Prevention of Atrial Fibrillation in Adult Patients with Congestive Heart Failure: A Meta-analysis of Randomized Controlled Trials

BACKGROUND: Onset of atrial fibrillation (AF) is related to congestive heart failure (CHF) severity. The renin angiotensin-aldosterone system activates the mineralcorticoid receptor in patients with CHF, increasing the concentration of aldosterone and cortisol levels. Prolonged, these may cause deleterious effects leading to arrhythmia, worsening of CHF and mortality. Aldosterone antagonists may influence the atrial fibrosis and remodeling, which may prevent the onset of AF in patients with CHF. METHODS: Randomized, double-blind trials were searched from PUBMED, Medline, Embase and Cochrane on the effect of aldosterone antagonists (i.e., spironolactone, eplerenone, or canrenone) vs placebo on the prevention of AF, worsening CHF and deaths from cardiovascular causes. Selected studies were subjected to meta-analysis on the effects on incidence of new-onset AF, death from cardiovascular causes, hospitalization from CHF, and hypokalemia. RESULTS: Four randomized trials were selected, for a total of 5,114 patients were identified and extracted. Aldosterone antagonists reduced the incidence of new-onset AF by 42% (relative risk [RR] 0.58; 95% CI 0.40, 0.85; p=0.005) vs placebo. Mortality from cardiovascular causes was reduced by 21% (RR 0.79; 95% CI 0.65, 0.96; p=0.002). The risk of hospitalization from CHF was reduced by 37% (RR 0.63; 95% CI 0.53, 0.76; p=0.00001). CONCLUSION: The additional of aldosterone antagonists to the treatment of CHF significantly reduced the risk of new-onset AF, hospitalization from CHF, and deaths from cardiovascular causes.

Flecainide versus vernakalant for conversion of recent-onset atrial fibrillation

An oral single dose of flecainide is used worldwide for conversion of recent onset atrial fibrillation (AF) in hemodynamically stable patients without structural heart disease. Vernakalant is a novel, rapid drug, which is used intravenously, with proven effectiveness and safety compared to placebo and amiodarone in randomized clinical trials. The aim of our study was to compare the time taken for conversion of recent onset AF in patients treated with vernakalant or flecainide. This is a sequential study in which 32 hemodynamically stable patients with recent onset AF without structural heart disease were prospectively and consecutively included in two periods, one for each drug. A single oral dose of flecainide 300 mg was administered to 15 patients and 17 patients received intravenous vernakalant. Clinical and laboratory variables, conversion rate and time to conversion were recorded. Baseline characteristics were similar in both groups. Time to conversion to sinus rhythm was of 163 min (120-300) in the flecainide group versus 10 min (6-18) in the vernakalant group (p=0.0001). Time to conversion of AF to sinus rhythm was significantly shorter in the vernakalant group compared with the flecainide group, and was associated with shorter hospital stay. This reduction in hospital stay length may produce benefits in patients' medical care, costs and welfare.

015: Relation between platelet activation and inflammation indexes measured on admission and new onset atrial fibrillation in patients with acute myocardial infarction

Platelet activation is present in atrial fibrillation (AF), but there is some debate whether this is due to AF itself and/or to underlying cardiovascular diseases. We aim to determine the association between a marker of platelet reactivity (mean platelet volume (MPV)) and systemic inflammation (CRP) measured on admission, and new onset episode of AF in patients with MI. Prospective cohort of 4994 consecutive patients with AMI. Patients with paroxysmal or persistent AF were excluded. 426 (8.5%) patients were diagnosed with a new onset of AF during the in-hospital-stay (mean stay 3±2 days). These patients were older (75 vs 65, p<0.001), predominantly male, and prevalence of hypertension and diabetes was greater. Also less smoker were found among this group. Despite similar reperfusion strategies, clinical presentation with heart failure and increased heart rate (HR) was more frequently found in patients with AF. Left ventricular ejection fraction (LVEF) was significantly depressed in AF patients (47 vs. 55, p<0.001), among with increased NT-proBNP, admission MPV (8.9 vs. 8.6, p<0.001) and CRP (10.7 vs 5.7, p<0.001). Backward logistic regression analysis (model 1) found that age [OR=1.04, 95%CI (1.031–1.050), p<0.001)], HR [OR=1.016, 95%CI (1.011–1.021), p<0.001)], LVEF [OR=0.979, 95%CI (0.970–0.987), p<0.001)] and MPV [OR=1.182, 95%CI (1.064–1.312), p<0.001)] were independent predictors of AF occurrence. A second backward regression analysis (model 2= model 1+CRP) found that age [OR=1.036, 95%CI (1.026–1.046), p<0.001)], HR [OR=1.013, 95%CI (1.008–1.018), p<0.001)], LVEF [OR=0.977, 95%CI (0.968–0.987), p<0.001)] and CRP [OR=1.003, 95%CI (1.001–1.005), p=0.006)] were independent predictors of AF occurrence after MI. This study suggested that new onset of AF early after MI is rather linked to inflammation induced by myocardial damage or the existing atherosclerotic burden than platelet activation.

P216 Impact of Tachycardia and New Onset Atrial Fibrillation in Acute Exacerbations of COPD

Introduction and ObjectivesCardiac arrhythmias are regularly found in patients with COPD, with higher frequencies reported during exacerbations. We wished to examine the impact of tachycardia and new onset atrial fibrillation...

New Onset Atrial Fibrillation in Patients with Acute Periprocedural and Non-Peripocedural Ischemic Stroke (P06.249)

New Onset Atrial Fibrillation in Patients with Acute Periprocedural and Non-Peripocedural Ischemic Stroke (P06.249)

Above Which Blood Pressure Level Does the Risk of Atrial Fibrillation Increase?

See related article, pp 198–204 Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, occurs in 1% to 2% of the general population,1 and its incidence is growing. Mostly because of the progressive aging of the population, the prevalence of AF is expected to double over the next 50 years.1 AF is a potentially devastating condition for several reasons. It portends a 5-fold risk of stroke,2 and ischemic strokes that occur in people with AF are often fatal or leave surviving patients generally more disabled and at higher risk of recurrences compared with other causes of stroke. AF triples the risk of heart failure,3 doubles the risk of dementia, and markedly increases the risk of all-cause mortality.4 For the above reasons, prevention of AF through appropriate control of its modifiable risk factors is a public health priority. Unfortunately, despite numerous experimental and clinical studies, the individual risk of developing AF in a given time frame is still difficult to estimate.5 Hypertension is a well-known modifiable risk factor for AF,3,4 although it is unclear above which blood pressure (BP) level the risk of AF definitely increases and, even more important, which target BP level should be pursued to reduce the risk of AF in treated hypertensive patients. In a population based, case-control study of 433 patients with incident AF and 899 controls, the risk of AF doubled in participants with systolic BP ≥150 …

Prevention of atrial fibrillation in patients with aortic valve stenosis with candesartan treatment after aortic valve replacement

BackgroundAccumulating data has suggested that treatment with Angiotensin-II receptor antagonists can prevent the new onset of atrial fibrillation (AF). The aim of this study was to evaluate whether treatment with candesartan on top of conventional treatment could prevent new onset AF in patients with aortic valve stenosis (AS) after aortic valve replacement. Methods and resultsThe study was a single centre, consecutive; investigator initiated study using a prospective randomised blinded endpoint design. 91 patients with severe AS without known AF scheduled for aortic valve replacement (AVR) were randomised to candesartan 32mg once daily on top of conventional treatment or conventional therapy immediately after AVR. Patients were examined with ECG 3, 6, 9 and 12months after surgery, and Holter-ECG analysis after 3 and 12months. Primary endpoint was episode of AF with a duration exceeding 30s, on the ECG or Holter-ECG and/or patients hospitalised due to AF. 14 patients developed new onset AF during follow up. AF-free survival was significantly higher (94% vs 74%, p=0.02) in patients treated with candesartan. ConclusionIn patients with symptomatic severe AS undergoing AVR, treatment with candesartan may prevent the new onset of atrial fibrillation.

Relationship of functional mitral regurgitation to new-onset atrial fibrillation in acute myocardial infarction

Background/objectiveThe role of factors that increase left atrial pressure or cause acute left atrial dilatation is frequently emphasised in the pathogenesis of atrial fibrillation (AF) in patients with acute myocardial...

Postoperative Atrial Fibrillation After Noncardiothoracic Surgery: Is It Different From After Cardiothoracic Surgery?

Postoperative atrial fibrillation (AF) is the most common arrhythmia that occurs after both cardiac and noncardiac surgery. It is associated with an increased morbidity, longer hospital stay and higher hospital costs. In addition, one of the most important clinical consequences of postoperative AF might be an increased incidence of perioperative stroke.1) There have been many investigations on the incidence, predictors, prophylactic strategies, and management of postoperative AF in patients undergoing cardiothoracic surgery. However, few studies have investigated the incidence and consequences of AF after noncardiothoracic surgery. Refer to the page 100-104 New onset AF after cardiac surgery has been reported to occur in 12 to 40 percent of patients after coronary artery bypass surgery, and the rate is even higher after valve replacement surgery, as high as 60%.2) Predictors associated with an increased risk of postoperative AF, after cardiac surgery, include advanced age, postoperative electrolyte shifts, pericarditis, a history of preoperative AF, a history of congestive heart failure, and chronic obstructive pulmonary disease. Focusing on the incidence and risk factors associated with new onset AF after thoracic (noncardiac) surgery, Vaporciyan and colleagues reported on 2,588 patients and found that the overall incidence of postoperative AF was 12.3%, somewhat lower than that with cardiac surgery; this is consistent with the results of previous reports.3),4) Significant multivariate predictors of AF after thoracic surgery include a male gender, older patient age, history of congestive heart failure, history of arrhythmias, and history of peripheral vascular disease.5) New onset AF, after cardiac and thoracic surgery, is likely triggered by direct intrathoracic stimulation or atrial irritation. It is, therefore, not surprising that the incidence of AF has been found to be lower when surgery does not involve the thorax. In one prospective series of 916 patients over 40 years of age undergoing major noncardiothoracic surgery, the incidence of AF was 2.5%;6) another more recently published study reported much lower incidence, 0.37%.7) Sohn and colleagues added and extended the observations on the topic of AF after noncardiothoracic surgery in this issue of the journal. They report the incidence of postoperative AF after noncardiothoracic surgery was 0.39%, and found that it was a relatively rare complication; it was associated with older age, and emergency surgery, and it extended the hospital stay. Their observations of significant multivariate predictors are different from those reported by Vaporciyan and colleagues. However, diverse patient groups were studied and different cardiac monitoring was used. Therefore, interpretation of the results should be made with consideration of the differences between the studies. The clinicians, especially cardiologists who are likely to care for patients prone to postoperative cardiac complications, consider which patients might benefit from prophylactic strategies. Prospective randomized trials have examined the utility of variety of pharmacological agents and nonpharmacological methods for prophylaxis in patients undergoing cardiothoracic surgery. Although the results have been conflicting, most investigators would agree that β-blockers can serve as effective prophylactic treatment with amiodarone and sotalol as alternative medications. It is uncertain whether such prophylactic medication would be effective in patients undergoing noncardiothoracic surgery because the mechanism of the postoperative AF might be somewhat different. If postoperative AF results from a preexisting electrophysiological substrate with a superimposed trigger, the latter factor might be more important in noncardiothoracic surgery. Therefore, extrapolation of the prophylactic strategies used in patients undergoing cardiothoracic surgery to the entire population of patients undergoing noncardiac surgery may not be warranted.8) Although most episodes of postoperative AF are self-limited, the natural course of postoperative AF after noncardiothoracic surgery should be defined. AF persisting for longer than 48 hours is associated with an increased risk of stroke or transient ischemic attack. Thus, after 48 hours of AF, anticoagulation should be considered, weighing the potential benefits against the risk of postoperative bleeding.9) The article reported by Sohn and colleagues raises concern with regard to postoperative AF after noncardiothoracic surgery; they suggest that it might be different from AF after cardiothoracic surgery in its pathogenesis, natural course and required management. To date, there have been no randomized controlled trials on new onset AF complicating noncardiothoracic surgery. Therefore, larger trials are needed to provide evidence based safe and effective strategies for the management of new onset AF in patients undergoing noncardiothoracic surgery.

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.

Prediction of atrial fibrillation in patients with cardiac dysfunctions†

Atrial fibrillation (AF) is a common arrhythmia in advanced heart failure. The occurrence of AF increases the risk of death and hospitalization for patients with heart failure. The results of different studies indicated that patients with paroxysmal AF have a longer filtered P wave duration (FPD), a lower root mean square voltage of the last 20 ms of the P wave (RMS 20), and a lower chemoreflexsensitivity (CHRS). Our study bases on these observations in order to examine the methods for predicting AF in patients with a left ventricular ejection fraction below 40% without a prior documentation of AF. The ratio between the difference of RR intervals in ECG and venous pO(2) before and after 5-min oxygen inhalation was measured (ms/mmHg) in order to determine the CHRS. A P wave signal-averaged ECG was performed for the measurement of FPD and RMS 20. The measurements were only performed in 94 patients with sinus rhythm. AF occurred during the mean follow-up of 39.9 months in 24 patients (26%). There were no significant differences concerning age, heart diseases, sex, ejection fraction, heart rate, or the use of drugs. The FPD (130.3 +/- 4.2 vs. 118.9 +/- 12.4 ms, P < 0.0001) was significantly longer and the RMS 20 (3.03 +/- 0.95 vs. 3.83 +/- 1.58 microV, P = 0.02) was significantly lower in patients with AF than in sinus rhythm. The CHRS did not differ significantly between both groups (3.57 +/- 1.49 vs. 3.48 +/- 1.62 ms/mmHg, P = 0.81). The chi(2) test showed that the threshold of FPD>or=125 ms and RMS 20 <or=3.3 microV revealed the best predictive value for AF. A stepwise logistic regression analysis of all variables identified the threshold of FPD>or=125 ms and RMS 20 <or=3.3 microV (OR 18.71; 95% CI, 4.85-72.16, P < 0.0001) as independent predictors for AF. In summary, our data show that the results of a P wave signal-averaged ECG can predict the risk for new onset of AF in patients with heart failure. The value of signal-averaged FPD is probably the result of reflecting the intra-atrial conduction delay, which is a pathophysiological condition for AF. The CHRS is not a suitable method for predicting AF.

Altered complexity and correlation properties of R-R interval dynamics before the spontaneous onset of paroxysmal atrial fibrillation.

Trigger mechanisms for the onset of paroxysmal atrial fibrillation (AF) in patients without structural heart disease are not well established. New analysis methods of heart rate (HR) variability based on nonlinear system theory may reveal features and abnormalities in R-R interval behavior that are not detectable by traditional analysis methods. The purpose of this study was to reveal possible alterations in the dynamics of R-R intervals before the spontaneous onset of paroxysmal AF. Traditional time and frequency domain HR variability indices, along with the short-term scaling exponent alpha(1) and approximate entropy (ApEn), were analyzed in 20-minute intervals before 92 episodes of spontaneous, paroxysmal AF in 22 patients without structural heart disease. Traditional HR variability measures showed no significant changes before the onset of AF. A progressive decrease occurred both in ApEn (1.09+/-0.26 120 to 100 minutes before AF; 0.88+/-0.24 20 to 0 minutes before AF; P<0.001) and in alpha(1) (1.01+/-0.28 120 to 100 minutes before AF, 0.89+/-0.28 20 to 0 minutes before AF; P<0.05) before the AF episodes. Both ApEn (0. 89+/-0.27 versus 1.02+/-0.30; P<0.05) and alpha(1) (0.91+/-0.28 versus 1.27+/-0.21; P<0.001) were also lower before the onset of AF compared with values obtained from matched healthy control subjects. A decrease in the complexity of R-R intervals and altered fractal properties in short-term R-R interval dynamics precede the spontaneous onset of AF in patients with no structural heart disease. Further studies are needed to determine the physiological correlates of these new, nonlinear HR variability measures.

Augmented Sympathoadrenal Activity during Treadmill Exercise in Patients With Wolff-Parkinson-White Syndrome and Atrial Fibrillation

It is believed that reciprocating tachycardia and accessory pathways play important roles in atrial fibrillation (AF) in patients with Wolff-Parkinson-White (WPW) syndrome. However, the mechanism by which AF occurs is not yet fully understood. This study was performed to evaluate the contribution of sympathoadrenal activity to the onset of AF in patients with WPW syndrome. Symptom-limited treadmill exercise testing was performed and plasma norepinephrine and epinephrine concentrations were measured simultaneously in 27 patients with WPW syndrome and 20 control subjects. In 13 patients with WPW syndrome and AF, plasma norepinephrine and epinephrine concentrations increased to 3.69 +/- 2.44 and 0.76 +/- 0.69 ng/ml at maximum exercise, respectively. These values were significantly higher (p < 0.001) than those in control subjects and in patients without AF. Pretreatment with 0.2 mg/kg of propranolol significantly reduced the incidence of exercise-induced atrial premature complexes (chi 2 = 7.33, p < 0.05). With oral beta-blockade for an average of 22.8 months, the incidence of AF decreased significantly from 1.77 +/- 0.53/patient per year to 0.33 +/- 0.57/patient per year (p < 0.001). Augmented sympathoadrenal activity in patients with WPW syndrome may contribute to AF.