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Europace Advance Access originally published online on November 12, 2007
Europace 2008 10(1):9-14; doi:10.1093/europace/eum233
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Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2007. For permissions please email: journals.permissions@oxfordjournals.org

ATRIAL FIBRILLATION

Predictors of arrhythmia recurrence in patients with lone atrial fibrillation

Germán Arriagada {dagger}, Antonio Berruezo {dagger}, Lluís Mont*, David Tamborero, Irma Molina, Blanca Coll-Vinent, Bárbara Vidal, Marta Sitges, Paola Berne, Josep Brugada on behalf of the GIRAFA (Grup Integrat de Recerca en Fibril·lació Auricular) Investigators

Thorax Institute, Hospital Clínic, University of Barcelona, Villarroel 170, Barcelona 08036, Catalonia, Spain Institut D'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS)

Manuscript submitted 20 April 2007. Accepted after revision 26 September 2007.

* Corresponding author. Tel: +34 932275551; fax: +34 93 451 30 45. E-mail address: lmont{at}clinic.ub.es


   Abstract
Top
 Abstract
Introduction
 Methods
 Results
 Discussion
 Clinical implications
 Limitations
 Conclusions
 Funding
 References
 
Aims: The need for antiarrhythmic drugs (AAD) after a first episode of atrial fibrillation (AF) is determined by the probability of recurrence. The aim of this study was to asses the probability of relapse and the predictors of recurrence in patients with idiopathic AF.

Methods and results: A cohort of 98 consecutive patients younger than 65 years admitted at the emergency room because of an episode of symptomatic idiopathic (lone) AF was included in this study. On admission, a complete medical history was taken, and an echocardiogram and 24-h Holter monitoring were performed. Patients were seen at 3 and 6 months after the index episode. There were 35 (35.7%) patients with a new-onset AF episode and 63 (64.3%) with a recurrent AF episode. A majority of them were male (71%), with a mean age of 48±11 years. Patients with new-onset AF episodes did not receive AAD. At 6 month follow-up, 57% of all patients suffered at least one symptomatic AF relapse. Patients with AF relapses belong more often to the recurrent group vs. new-onset group of AF (65.1 vs. 34.9%, respectively, P = 0.03); they had larger LA diameter indexed for body surface area (BSA) (22.6±3.7 vs. 19.8±3.2 mm/m2, P = 0.001), larger left ventricular end-systolic diameter (18.4±3.1 vs. 17.2±2.5 mm/m2, P = 0.05) and a tendency towards a higher proportion of atrial tachycardia runs on Holter (66.7 vs. 50%, P = 0.09). Logistic regression analysis showed that the presence of previous episodes of AF (OR: 3.2; 95% CI; 1.0–8.0, P = 0.04) and a larger anteroposterior LA diameter (OR: 1.3; 95% CI; 1.1–1.6, P = 0.001) were independent predictors of AF recurrences at 6 months.

Conclusions: The recurrence rate in lone AF patients is high. The presence of previous episodes and a mildly enlarged anteroposterior LA diameter increase the probability of relapse of lone AF.

Key Words: Lone atrial fibrillation, Antiarrhythmic drugs


   Introduction
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 Abstract
 Introduction
Methods
 Results
 Discussion
 Clinical implications
 Limitations
 Conclusions
 Funding
 References
 
Atrial fibrillation (AF) is the most common arrhythmia in general population. Patients with AF are heterogeneous in their clinical presentation, severity of symptoms, and underlying cardiovascular disease.1Go Lone AF is clinically defined, as an arrhythmia that occurs in the absence of structural heart disease or any other causal factors, and is considered a benign disorder in patients younger than 60 years.2Go The optimal management of this population is not clearly defined yet. ACC/AHA/ESC guidelines recommend a pharmacological management, according to the patients' clinical presentation, mainly regarding the intensity of symptoms, the number of previous episodes of AF, and the type of AF (paroxysmal vs. persistent). The need for anticoagulant therapy is determined by the presence of risk factors for thromboembolism. However, these recommendations are not based on the recurrence rate of AF, probably because of the lack of data, since major clinical trials published only include a minimal proportion of patients with lone AF and have not analysed the predictors of AF recurrence in this group of patients.3Go–5Go

On the other hand, it is demonstrated that an enlargement of the left atrium (LA) is related to the presence of AF in patients with structural heart disease and in those with lone AF.6Go Specifically, in a case of paroxysmal lone AF, it is proved that LA dilatation is present, suggesting that there is an anatomical substrate that promotes the development of the arrhythmia.7Go However, it is not assessed the usefulness of the measurement of the cardiac dimensions and function in estimating the probability of recurrences of patients with lone AF. Therefore, the aim of the study is to assess the recurrence rate and the clinical and echocardiographic predictors of recurrences in a cohort of non-selected consecutive patients with symptomatic idiopathic AF.


   Methods
Top
 Abstract
 Introduction
 Methods
Results
 Discussion
 Clinical implications
 Limitations
 Conclusions
 Funding
 References
 
Study population
A total of 98 consecutive patients younger than 65 years, admitted at emergency department between January 2001 and June 2005 due to a symptomatic AF of <48 h of onset and without structural heart disease, were included in the study. Patients with AF of unknown duration were excluded.

To evaluate the presence of a structural heart disease, a detailed clinical history, physical examination, and a 2-D echocardiography were performed. Furthermore, other secondary causes of AF were excluded through complementary exams that included a chest X-ray, ECG, thyroid hormones, haemogram, creatinin, electrolytes, glycaemia and prothrombin time and cardiac enzymes if chest pain or any ECG abnormality. In addition, 24 h Holter monitoring was performed in all patients included in the study.

Definitions
Atrial fibrillation was defined as paroxysmal when the arrhythmia terminated within 48 h, without the need of electrical cardioversion. If the arrhythmia required electrical cardioversion was defined as persistent. The first-detected episode was defined as new-onset AF. Patients with previous AF before the index episode were classified as recurrent AF. The definitions had to be adapted to the recommended therapeutic protocol at the emergency room for idiopathic AF that includes oral flecainide (200 mg followed by 100 mg every 12 h) and electrical cardioversion if sinus rhythm was not recovered within 48 h.

Patients were included in the study after written informed consent form was obtained. The study protocol was approved by the local Ethics Committee.

Comprehensive transthoracic echocardiography was performed using a commercially available system and images were digitally stored for later off-line analysis. All measurements were made when the patient was in sinus rhythm. M-mode and 2-D scans were obtained following the recommendations of the American Society of Echocardiography.8Go LA size was evaluated in the anteroposterior dimension (from the long paraesternal view) and in the transversal (medio-lateral) and longitudinal (infero-superior) dimensions (from the apical four-chamber view). Additionally, left atrial maximum (end-systole) area and volume were determined, also from apical four-chamber view. Left ventricular (LV) diastolic function was assessed in terms of LV inflow diastolic velocities, pulmonary vein flow and lateral mitral annulus motion. All cardiac dimensions were indexed for body surface area (BSA) of each patient.

Exclusion criteria were of age <18 and >65 years, any cardiovascular disease, any ECG abnormality, other diseases like systemic hypertension, diabetes mellitus, chronic obstructive pulmonary disease, chronic liver disease, infectious disease, inflammatory disease and AF secondary to drugs, hypoxemia, alcohol abuse, and thyroid disease. We did not perform routine exercise test to rule out ischaemic heart disease because the low prevalence in this specific and highly selected population.

Follow-up
According to clinical guidelines, antiarrhythmic drugs (AAD) were used. Only patients with preceding AF episodes were taken AAD during the study. Physicians started Ic class AAD treatment if the patient was not taking AAD previously. If the patient was already taken AAD and was considered refractory to Ic, then amiodarona was recommended. None of the new-onset AF patients received AAD medication after discharge. None of the whole cohort received anticoagulant treatment. If cardioversion was considered after discharge, acenocumarol was administered during three weeks previous to and after cardioversion.

Follow-up consisted in an outpatient visit at 3 and 6 months after discharge. Serial ECGs were recorded at each visit to document the maintenance of sinus rhythm or the recurrence of AF. Patients were also asked to report if they had any symptoms of arrhythmia between the scheduled visits. A patient was considered as having recurrences when AF was documented through an ECG or Holter recording, or when symptoms were highly suggestive of a recurrent episode.

Statistical analysis
Continuous variables were expressed as mean ± SD. Student's t-test was used for continuous variables and {chi}2 test for categorical variables. Multivariate analysis was done using forward stepwise logistic regression analysis, with a P < 0.05 as error and P < 0.10 as remove criteria (hazard ratio, 95% confidence interval). Linearity assumption of those continuous variables included in the multivariable analysis was assessed by performing a wald test. A two sided P-value ≤0.05 was considered statistically significant. All the analyses were performed with a commercially available package (SPSS software, version 11.0).


   Results
Top
 Abstract
 Introduction
 Methods
 Results
Discussion
 Clinical implications
 Limitations
 Conclusions
 Funding
 References
 
We analysed a cohort of 98 consecutive patients that were admitted at the emergency department for an acute onset (<48 h) episode of symptomatic idiopathic AF. According to our archive data, ~210 patients per month, with history of AF, were visited during the inclusion period of the study at the medical area of the emergency room. Only 15% of them were younger than 65 years old and 62% of them (9% of the whole group) had none of the exclusion criteria. Finally, only 43% of the remaining patients (1.4% of the entire group) had documented AF in the ECG on admission. It means ~2 to 3 eligible patients per month. Baseline characteristics of the whole group are listed in Table 1. On admission there were 35 (35.7%) patients with new-onset AF and 63 (64.3%) with previous episodes of AF. Majority of them were males (71.4%) with a mean age of 48 ± 11 years (range 18–65). A 25.8% of patients had a mildly enlarged LA indexed for BSA according to recent recommendations.9Go


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  		Table 1 Baseline characteristics of patients with idiopathic AF included in the study

 
A total of 50 patients (51%) of the whole group had a paroxysmal index episode that reverted to sinus rhythm spontaneously or after oral flecainide. The remaining 48 (49%) required an electrical cardioversion, and were considered as a persistent AF episode.

Follow-up was completed by 100% of patients. At 6-months follow-up 56 (57%) patients of the entire group presented a recurrent episode of AF. Univariate analysis (Table 2) showed that there were more AF relapses in patients with previous AF episodes than in patients with a new-onset AF at the inclusion in the study (65.1 vs. 34.9%, respectively, P = 0.03) despite the use of AAD in 70% in the former. Patients with atrial tachycardia runs on baseline 24 h Holter monitoring had a tendency towards a higher recurrence rate (66.7 vs. 50.0%, P = 0.09). Among the echocardiographic parameters, those with recurrences during follow-up had a larger anteroposterior LA diameter and larger LV end-systolic diameter. There were no differences in age, sex, and AF classification (paroxysmal vs. persistent) or any additional echocardiographic measurements (LA area, LA volume, Doppler measures, etc). Finally, the percentage of patients taking AAD was not different between recurrent vs. non-recurrent patients in the group of preceding AF at the inclusion moment (Table 3). None of the patients who had a first AF episode at the moment of the inclusion were taken AAD after the emergency room discharge.


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  		Table 2 Univariate predictors of atrial fibrillation recurrence

 


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  		Table 3 Percentage of patients taking AAD between recurrent vs. non recurrent patients in the group of preceding AF at the inclusion moment

 
Logistic regression analysis showed that the probability of AF relapse was higher in patients presenting at the emergency room with a recurrent episode of idiopathic vs. new onset AF (OR: 3.1; CI 95%; 1.0–8.0, P = 0.04) and in patients with larger anteroposterior LA diameter (OR: 1.3 per each milimeter increase; CI 95%; 1.1–1.6, P = 0.001). When the LAD is uncorrected for BSA, the measurement is not predictive of recurrences. With these two independent predictors, the mean predicted proportion of AF recurrences of the multivariate model showed a direct relationship between the probability of recurrences and the increasing anteroposterior LA diameter. Furthermore, the distinction between new-onset and recurrent episodes of lone AF helps in identifying two groups with different probabilities of AF recurrence for each LA diameter (Figure 1).


Figure 1
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  		Figure 1 The figure shows the mean predicted proportion of patients with AF recurrence related to left atrial size (expressed as anteroposterior LA diameter indexed for BSA) and to the clinical presentation at baseline (new-onset vs. recurrent AF).

 

   Discussion
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
Clinical implications
 Limitations
 Conclusions
 Funding
 References
 
It is known that age, cardiomyopathy, mitral valve disease, hypertension, and an enlarged LA size are predictors of recurrence in patients with AF1Go and predictors of progression to chronic AF.10Go However, little is known about the population of lone AF that represent between 10 and 30% of patients with AF.2Go,11Go,12Go Since different diagnostic and recruitment criteria, non-uniform demographic characteristics, and technology have been used to identify patients with lone AF, there is a limited information regarding the natural history of lone AF.2Go,13Go–15Go Furthermore, AF is a complex arrhythmia, as its variable clinical presentation and underlying pathophysiology suggest.16Go–18Go Many management strategies are available and there is still a debate on which strategy to use in the different patient groups. In patients with lone AF, a group seldom, if ever, included in large clinical trials, the recommended management is to evaluate the symptoms and the number of previous AF episodes prior to starting pharmacological treatment.1Go Regarding the results of this study, one could suggest to take into account the anteroposterior LA diameter (indexed for BSA) to decide to treat or not with AAD.

In the study of Rostagno et al.14Go patients with idiopathic AF could experience a recurrent episode in up to 59% over an average follow-up period of 6 years. Another study has shown a recurrence rate of 75% in patients with a paroxysmal lone AF after a mean follow-up period of 8 years of clinical diagnosis.19Go The present study shows a higher incidence of relapse of AF in the whole group, a 57% of recurrence in a period of 6 months follow-up after the index episode. Nonetheless, the differences might be explained in part by the fact that patients were also included in a case of preceding AF and this group has a 65% recurrence in this period. With the two independent predictors of recurrence identified, it is possible to create different subgroups of lone AF patients: those with or without a mildly dilated LA9Go and the preexistent vs. new-onset episode of AF (Figure 2). Thus, our observations not necessarily disagree with the previous ones, with respect to the recurrence rates. It is possible that patients differ in some characteristics, like LA dimensions; however, it is difficult to determine because not all patients in the most important series had an echocardiogram at inclusion.2Go,13Go


Figure 2
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  		Figure 2 Mean predicted proportion of patients with AF recurrence at 6 months follow-up in the four groups created by the combination of the left atrial size and clinical presentation at baseline.

 
Another important issue is the observation that the probability of recurrence was independent on whether the index episodes of AF were paroxysmal or persistent.

Previous studies had demonstrated that AF and an enlarged LA size, both are independent predictors of adverse events and mortality in patients with cardiovascular disease and in the general population.20Go,21Go Thus, it maybe also valid for patients with idiopathic AF,22Go in whom the enlarged LA might be the expression of increased filling pressure and diastolic dysfunction, as it is suggested previously.22Go–24Go However, in the present study the group with recurrences did not show statistically significant differences in echocardiographic parameters evaluating diastolic dysfunction. Larger follow-up studies are needed to clarify this point. In the same way, a recent 30-year follow-up study has demonstrated that the long-term mortality of patients with lone AF and without LA enlargement is similar to the general age- and sex-matched population. The study also point out that AF is a heterogeneous disorder and that comorbidities (as the age at diagnosis and the development of hypertension) significantly modulate disease progression and complications25Go.

Despite it is well recognized that anteroposterior diameter of the LA is not a precise measurement of the real size of the LA,9Go,26Go in our group of patients this was the only parameter that predicted AF recurrences. This is in accordance with other previous studies that have found that anteroposterior LA diameter is a strong predictor of future arrhythmia episodes in other clinical settings rather than lone AF. It may be speculated that LA dilatation in the AP dimension may favor AF development more than dilatation of the LA in the longitudinal or transversal axis.


   Clinical implications
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Clinical implications
Limitations
 Conclusions
 Funding
 References
 
These observations could help physicians to tailor pharmacologic management in patients with lone AF on admission and during follow-up. If the patient has a recurrent episode of lone AF and a dilated anteroposterior LA diameter indexed for BSA, the probability of recurrence is around 90% despite the use of AAD. Thus, another therapeutic approach may be necessary. In that respect, it might be appropriate to offer AF ablation or other drugs with antiarrhythmic properties (i.e. angiotensin receptor blockers, statins, etc) instead or in addition to antiarrhythmics, as the treatment of choice.27Go In particular, AF ablation may be an alternative because its good results in the population with mildly enlarged atria.1Go,28Go

On the contrary, when the patient has a new-onset lone AF and a non-dilated anteroposterior LA indexed for BSA, the probability of recurrence without AAD is around 30%. In this case and also probably in a case of new-onset lone AF with LA dilatation, the best treatment option needs to be investigated.


   Limitations
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 Abstract
 Introduction
 Methods
 Results
 Discussion
 Clinical implications
 Limitations
Conclusions
 Funding
 References
 
One limitation of the study is the possibility of underestimating the true recurrence rate of AF, because, it is demonstrated that some patients have asymptomatic, ‘silent’ episodes of AF during the follow-up.29Go Even among patients with a symptomatic first episode of AF, asymptomatic recurrences are possible.

Another limitation of the study is the relatively small sample size, although enough to identify useful predictors of recurrence in this population. The study analyses the recurrence rate only during 6 months period, thus the recurrence rate and the clinical implications may differ with longer follow-up.

Finally, the possible pro-arrhythmic effect of AAD may have been underestimated. However, it is demonstrated that in the majority of patients their capability to prevent recurrences overcomes that of the placebo effect.1Go


   Conclusions
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Clinical implications
 Limitations
 Conclusions
Funding
 References
 
Recurrence after a first-detected episode of idiopathic AF is high, both in new-onset and recurrent AF, despite the use of antiarrhythmics in the latter. An enlarged anteroposterior LA diameter indexed for BSA and the presence of a recurrent episode at initial presentation are independent predictors for AF recurrence. The results may help in selecting patients for different treatment strategies.

Conflict of interest: none declared.


   Funding
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Clinical implications
 Limitations
 Conclusions
 Funding
References
 
For this study, we received a grant from the ‘Fundació Clinic per a la Recerca Biomédica.


   Footnotes
 
{dagger} The first two authors contributed equally to this work. Back


   References
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Clinical implications
 Limitations
 Conclusions
 Funding
 References
 
[1] Fuster V, Ryden LE, Asinger RW, Cannom DS, Crijns HJ, Frye RL, et al. American College of Cardiology/American Heart Association Task Force on Practice Guidelines, European Society of Cardiology Committee for Practice Guidelines and Policy Conferences, North American Society of Pacing and Electrophysiology. ACC/AHA/ESC Guidelines for the Management of Patients With Atrial Fibrillation: Executive Summary. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines and Policy Conferences (Committee to Develop Guidelines for the Management of Patients With Atrial Fibrillation) Developed in Collaboration With the North American Society of Pacing and Electrophysiology. Circulation (2001) 104:2118–50.[Free Full Text]

[2] Kopecky SL, Gersh BJ, McGoon MD, Whisnant JP, Holmes DR Jr, Ilstrup DM, et al. The natural history of lone atrial fibrillation: a population-based study over three decades. N Engl J Med (1987) 317:669–74.[Abstract]

[3] Wyse DG, Waldo AL, DiMarco JP, Domanski JP, Rosemberg Y, Schron EB, et al, For the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) investigators. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med (2002) 347:1825–33.[Abstract/Free Full Text]

[4] Van Gelder IC, Hagens VE, Bosker HA, Kingma JH, Kamp O, Kingma T, et al, For the Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation Study Group. A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation. N Engl J Med (2002) 347:1834–40.[Abstract/Free Full Text]

[5] Rienstra M, Hagens VE, Van Veldhuisen DJ, Bosker HA, Tijssen JGP, Kamp O, et al. Clinical characteristics of persistent lone atrial fibrillation in the RACE study. Am J Cardiol (2004) 94:1486–90.[CrossRef][Web of Science][Medline]

[6] Thamilarasan M, Klein AL. Factors relating to left atrial enlargement in atrial fibrillation: ‘chicken or the egg’ hypothesis. Am Heart J (1999) 137:381–3.[CrossRef][Web of Science][Medline]

[7] Sitges M, Teijeira VA, Scalise A, Vidal B, Tamborero D, Collvinent B, et al. Is there an anatomical substrate for idiopathic paroxismal atrial fibrillation? A case-control echocardiographic study. Europace (2007) 9:294–8.[Abstract/Free Full Text]

[8] Gardin JM, Adams DB, Douglas PS, Feigenbaum H, Forst DH, Fraser AG, et al. American Society of echocardiography. Recommendations for a standardized report for adult transthoracic echocardiography: a report from the American Society of Echocardiography's Nomenclature and Standards Committee and Task Force for a Standardized Echocardiography Report. J Am Soc Echocardiogr (2002) 15:275–90.[CrossRef][Web of Science][Medline]

[9] Lang RM, Bierig M, Devereux RB, Flachskampf FA, Foster E, Pellikka PA, et al. Recommendations for chamber quantification. Eur J Echocardiogr (2006) 7:79–108.[Abstract/Free Full Text]

[10] Kerr CR, Humpries KH, Talajic M, Klein GJ, Connolly SJ, Gren M, et al. Progression to chronic atrial fibrillation following the initial diagnosis of paroxysmal atrial fibrillation. Am Heart J (2005) 149:489–96.[CrossRef][Web of Science][Medline]

[11] Levy S, Maarek M, Coumel P, Gieze L, Lekieffre J, Medvedowsky JL, et al. Characterization of different subsets of atrial fibrillation in general practice in France: the ALFA study. Circulation (1999) 99:3028–35.[Abstract/Free Full Text]

[12] Gersh BJ, Solomon A. Lone atrial fibrillation: epidemiology and natural history. Am Heart J (1999) 137:592–5.[CrossRef][Web of Science][Medline]

[13] Brand FN, Abbott RD, Kannel WB, Wolf PA. Characteristics and prognosis of lone atrial fibrillation: 30-years follow up in the Framingham study. JAMA (1985) 254:3449–53.[Abstract/Free Full Text]

[14] Rostagno C, Bacci F, Martelli M, Naldoni A, Bertini G, Gensini G. Clinical course of lone atrial fibrillation since first symptomatic arrhythmic episode. Am J Cardiol (1995) 76:837–9.[CrossRef][Web of Science][Medline]

[15] Planas F, Antúnez F, Poblet T, Pujol M, Romero C, Sadurní J, et al. Perfil clínico de la fibrilación auricular paroxística idiopática (registro FAP). Rev Esp Cardiol (2001) 54:838–44.[Web of Science][Medline]

[16] Haissaguerre M, Jais P, Shah DC, Takahashi A, Hocini M, Quiniou G, et al. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl Med (1998) 39:659–66.

[17] Jalife J, Berenfeld O, Mansour M. Mother rotors and fibrillatory conduction: a mechanism of atrial fibrillation. Cardiovasc Res (2002) 54:204–16.[Abstract/Free Full Text]

[18] Hirose M, Takeishi Y, Miyamoto T, Kubota I, Laurita KR, Chiba S. Mechanism for atrial tachyarrhythmia in chronic volume overload-induced dilated atria. J Cardiovasc Electrophysiol (2005) 16:760–9.[CrossRef][Web of Science][Medline]

[19] Scardi S, Mazzone C, Pandullo C, Goldstein D, Poletti A, Humar F. Lone atrial fibrillation: prognostic differences between paroxysmal and chronic forms after 10 years follow-up. Am Heart J (1999) 137:686–91.[CrossRef][Web of Science][Medline]

[20] Benjamin EJ, Wolf PA, D'Agostino RB, Silvershatz H, Kannel WB, Levy D. Impact of atrial fibrillation on the risk of death: the Framingham Heart Study. Circulation (1998) 98:946–52.[Abstract/Free Full Text]

[21] Psaty BM, Manolio TA, Kuller LH, Kronmal RA, Cushman M, Fried LP, et al. Incidence of and risk factors for atrial fibrillation in older adults. Circulation (1997) 96:2455–61.[Abstract/Free Full Text]

[22] Osranek M, Bursi F, Bailey KR, Grossardt BR, Brown RD Jr, Kopecky SL, et al. Left atrial size volume predicts cardiovascular events in patients originally diagnosed with lone atrial fibrillation: three-decade follow-up. E Heart J (2005) 26:2556–61.[CrossRef]

[23] Jais P, Peng JT, Shah DC, Garrigue S, Hocini M, Yamane T, et al. Left ventricular diastolic dysfunction in patients with so-called lone atrial fibrillation. J Cardiovasc Electrophysiol. (2000) 11:623–5.

[24] Tsang TS, Gersh BJ, Appleton CP, Tajik AJ, Barnes ME, Bailey KR, et al. Left atrial diastolic dysfunction as a predictor of the first diagnosed nonvalvular atrial fibrillation in 840 elderly men and women. J Am Coll Cardiol (2002) 40:1636–44.[Abstract/Free Full Text]

[25] Jahangir A, Lee V, Friedman PA, Trusty JM, Hodge DO, Kopecky SL, et al. Long-term progression and outcomes with aging in patients with lone atrial fibrillation: a 30-year follow-up study. Circulation (2007) 115:3050–6.[Abstract/Free Full Text]

[26] Lester SJ, Ryan EW, Schiller NB, Foster E. Best method in clinical practice and in research studies to determine left atrial size. Am J Cardiol (1999) 84:829–32.[CrossRef][Web of Science][Medline]

[27] Madrid AH, Bueno MG, Rebollo JM, Marin I, Pena G, Bernal G, et al. Use of irbesartan to maintain sinus rhythm in patients with long-lasting persistent atrial fibrillation: a prospective and randomized study. Circulation (2002) 16:331–6.

[28] Berruezo A, Tamborero D, Mont L, Sitges M, Benito B, Tolosana JM, et al. Pre-procedural predictors of atrial fibrillation recurrence after circumferential pulmonary vein ablation. Eur Heart J (2007) 28:836–41.[Abstract/Free Full Text]

[29] Page RL, Tilsch TW, Connolly SJ, Schnell DJ, Marcello SR, Wilkinson WE, et al. Asymptomatic or ‘silent’ atrial fibrillation: frequency in untreated patients and patients receiving azimilide. Circulation (2003) 107:1141–5.[Abstract/Free Full Text]


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