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| 2. |
- Hansson, Anders P, et al.
(författare)
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Right atrial free wall conduction velocity and degree of anisotropy in patients with stable sinus rhythm studied during open heart surgery
- 1998
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 19:2, s. 293-300
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Although the perpetuation of several supraventricular arrhythmias is critically dependent upon intra-atrial conduction, the literature lacks detailed information on normal values of conduction velocity and degree of anisotropy. In order to explore these factors further, we have measured conduction velocities at the right atrial free wall during sinus rhythm and during atrial pacing in four directions parallel and perpendicular to the atrioventricular groove in patients with normal atria and stable sinus rhythm. METHODS AND RESULTS: Using a Bard Cardiac Mapping System, atrial ECGs were recorded using a 3 x 4 cm electrode array with 56 equally spaced bipolar electrodes in 12 patients undergoing open heart surgery due to ischaemic heart disease or Wolf-Parkinson-White syndrome. A bipolar pen probe connected to a Medtronic 5328 stimulator was used for pacing at a 10% higher rate than sinus rhythm. The local activation times were manually set and isochronal activation maps were created for each recording. The conduction velocities were calculated from the activation maps over a distance ranging from 2.2 to 4.2 cm. The majority of the activation maps showed no signs of anisotropy; the others had less than 15% spatial inhomogeneity of conduction. Mean conduction velocity, calculated from five consecutive beats, was 88 +/- 9 cm.s-1 (mean +/- SD), ranging between 68 +/- 4 and 103 +/- 3 cm.s-1 during sinus rhythm. Mean conduction velocity during atrial pacing was 81 +/- 16 cm.s-1 at a propagation direction of 0 degree, 74 +/- 14 cm.s-1 at a 90 degrees direction, 79 +/- 12 cm.s-1 at 180 degrees and 78 +/- 20 cm.s-1 at 270 degrees, where 0 degree was parallel to the atrioventricular groove in the cranial direction and the angle increased counter-clockwise. Mean conduction velocity during sinus rhythm was significantly higher (P < 0.05) than during atrial pacing at the 90 degrees and 180 degrees directions but not compared to atrial pacing at 0 degree or 270 degrees. There was no significant difference in mean conduction velocity in different directions during atrial pacing. CONCLUSION: Although anisotropy was documented during conduction velocity in individual cases, conduction velocity was not dependent on propagation direction at the epicardial right atrial free wall in patients with stable sinus rhythm. These findings do not exclude the presence of internodal preferential pathways as these are located sub-epicardially and a marked transmural discordance in activation has previously been documented in the vicinity of such pathways.
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| 3. |
- Holm, Magnus, et al.
(författare)
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Epicardial right atrial free wall mapping in chronic atrial fibrillation. Documentation of repetitive activation with a focal spread--a hitherto unrecognised phenomenon in man
- 1997
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 18:2, s. 290-310
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Previous studies have shown that atrial fibrillation of recent onset in man is based on a varying number of simultaneously present activation waves reentering either themselves or each other. In the present study, right atrial activation during chronic atrial fibrillation in man was studied. METHODS AND RESULTS: In 16 patients with chronic atrial fibrillation multiple epicardial recordings of 8 s each were made at the right atrial posterior free wall and at the appendage using a 20 x 35 mm electrode array with 56 bipolar measurement points. The preferable activation pattern of each recording and the propagation direction, cycle length and conduction velocity of individual activation waves within each recording were determined. Activation was characterized by unorganised activation with several simultaneously present activation waves: inconsistent preferable activation pattern (n = 5), predominantly organised activation with either frequent episodes of uniform activation: consistent preferable activation pattern (n = 7) or frequent episodes of activation with focal spread; focal preferable activation pattern (n = 4). Random re-entry was frequently documented in recordings with the inconsistent preferable activation pattern and less frequently in recordings with the consistent and focal preferable activation pattern. Complete re-entry circuits were rarely documented. The median fibrillation cycle length was 146, 159 (P < 0.05) and 165 ms (not significant) and the mean conduction velocity during uniform activation was 64, 67 and 83 cm. s-1 (not significant) in recordings with the inconsistent, consistent and focal preferable activation pattern, respectively. CONCLUSIONS: During chronic atrial fibrillation in man, right atrial free wall activation ranges from disorganised activation with multiple co-existing activation waves to predominantly organised activation characterized by either uniform activation consistent with the presence of large re-entry circuits or repetitive activation of unknown mechanism and focal spread.
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| 4. |
- Holmqvist, Fredrik, et al.
(författare)
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Atrial fibrillatory rate and sinus rhythm maintenance in patients undergoing cardioversion of persistent atrial fibrillation.
- 2006
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 27:18, s. 2201-2207
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Tidskriftsartikel (refereegranskat)abstract
- The study set out to explore whether an index of atrial electrical electrophysiology can be used to predict atrial fibrillation (AF) relapse, and if the predictive properties differ as a result of arrhythmia duration. METHODS AND RESULTS: The study comprised 175 consecutive patients with persistent AF (median duration 94 days, range 2 to 1044) referred for cardioversion. Twenty-nine patients had arrhythmia duration under 30 days (median 5 days, range 2-26). Atrial fibrillatory rate (AFR) was estimated using a frequency power spectrum analysis of QRST-cancelled ECG. At 1-month follow-up, 56% of the patients had relapsed to AF. The pre-cardioversion mean AFR of those patients was 399+/-52 fibrillations per minute (fpm) compared with 363+/-63 fpm among patients maintaining SR (P<0.0001). In patients with short AF duration, the difference was even more pronounced (424+/-52 vs. 345+/-65 fpm, P<0.01). In this group, a finding of an AFR above the mean value of the study population predicted AF relapse with high accuracy. CONCLUSION: In patients undergoing cardioversion of persistent AF, AF relapse is predicted by a higher AFR. A stronger association is seen in patients with short arrhythmia duration, reflecting either rapid remodelling or pre-existing changes in those who relapse to AF.
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| 5. |
- Kirchhof, Paulus, et al.
(författare)
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Outcome parameters for trials in atrial fibrillation: executive summary
- 2007
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 28:22, s. 2803-2817
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Forskningsöversikt (refereegranskat)abstract
- Atrial fibrillation (AF), the most common atrial arrhythmia, has a complex aetiology and causes relevant morbidity and mortality due to different mechanisms, including but not limited to stroke, heart failure, and tachy- or bradyarrhythmia. Current therapeutic options (rate control, rhythm control, antithrombotic therapy, 'upstream therapy') only prevent a part of this burden of disease. Several new treatment modalities are therefore under evaluation in controlled trials. Given the multifold clinical consequences of AF, trials in AF patients should assess the effect of therapy in each of the main outcome domains. This paper describes an expert consensus of required outcome parameters in seven relevant outcome domains, namely death, stroke, symptoms and quality of life, rhythm, left ventricular function, cost, and emerging outcome parameters. In addition to these 'requirements' for outcome assessment in AF trials, further, more detailed outcome parameters are described. In addition to a careful selection of a relevant primary outcome parameter, coverage of outcomes in all major domains of AF- related morbidity and mortality is desirable for any clinical trial in AF.
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| 6. |
- Lip, Gregory Y. H., et al.
(författare)
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Oral direct thrombin inhibitor AZD0837 for the prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation: a randomized dose-guiding, safety, and tolerability study of four doses of AZD0837 vs. vitamin K antagonists
- 2009
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 30:23, s. 2897-2907
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Tidskriftsartikel (refereegranskat)abstract
- Aims Oral anticoagulation with vitamin K antagonists (VKAs) for stroke prevention in atrial fibrillation (AF) is effective but has significant limitations. AZD0837, a new oral anticoagulant, is a prodrug converted to a selective and reversible direct thrombin inhibitor (AR-H067637). We report from a Phase II randomized, dose-guiding study (NCT00684307) to assess safety, tolerability, pharmacokinetics, and pharmacodynamics of extended-release AZD0837 in patients with AF. Methods and results Atrial fibrillation patients (n = 955) with >= 1 additional risk factor for stroke were randomized to receive AZD0837 (150, 300, or 450 mg once daily or 200 mg twice daily) or VKA (international normalized ratio 2-3, target 2.5) for 3-9 months. Approximately 30% of patients were naive to VKA treatment. Total bleeding events were similar or lower in all AZD0837 groups (5.3-14.7%, mean exposure 138-145 days) vs. VKA (14.5%, mean exposure 161 days), with fewer clinically relevant bleeding events on AZD0837 150 and 300 mg once daily. Adverse events were similar between treatment groups; with AZD0837, the most common were gastrointestinal disorders (e.g. diarrhoea, flatulence, or nausea). D-Dimer, used as a biomarker of thrombogenesis, decreased in all groups in VKA-naive subjects with treatment, whereas in VKA pre-treated patients, D-dinner levels started tow and remained low in all groups. As expected, only a few strokes or systemic embolic events occurred. In the AZD0837 groups, mean S-creatinine increased by similar to 10% from baseline and returned to baseline following treatment cessation. The frequency of serum alanine aminotransferase >= 3 x upper limit of normal was similar for AZD0837 and VKA. Conclusion AZD0837 was generally well tolerated at all doses tested. AZD0837 treatment at an exposure corresponding to the 300 mg od dose in this study provides similar suppression of thrombogenesis at a potentially lower bleeding risk compared with dose-adjusted VKA.
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| 7. |
- Nieuwlaat, Robby, et al.
(författare)
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Antithrombotic treatment in real-life atrial fibrillation patients: a report from the Euro Heart Survey on Atrial Fibrillation
- 2006
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 27:24, s. 3018-3026
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Tidskriftsartikel (refereegranskat)abstract
- Aims To describe guideline adherence and application of different stroke risk strati. cation schemes regarding antithrombotic therapy in real-life atrial. brillation (AF) patients and to assess which factors influence antithrombotic management decisions. Methods and results The Euro Heart Survey enrolled 5333 AF patients in 35 countries, in 2003 and 2004. Prescription of antithrombotic drugs, especially oral anticoagulation (OAC), was hardly tailored to the patient's stroke risk pro. le as indicated by the joint guidelines of the American College of Cardiology, American Heart Association, and the European Society of Cardiology, ACCP guidelines, or CHADS(2) and Framingham risk scores. In multivariable analysis, only a limited number of the well-known stroke risk factors triggered OAC prescription. In contrast, less relevant factors, of which clinical type of AF and availability of an OAC monitoring outpatient clinic were the most marked, played a significant role in OAC prescription. Electrical cardioversions and catheter ablations clearly triggered OAC prescription, whereas pharmacological cardioversions even in the presence of stroke risk factors did not. Conclusion Antithrombotic therapy in AF is hardly tailored to the patient's stroke risk pro. le. Factors other than well-known stroke risk factors were significantly involved in antithrombotic management decisions. To facilitate this tailored treatment, guideline writers and physician educators should focus on providing one uniform and easy to use stroke risk strati. cation scheme.
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| 8. |
- Nieuwlaat, R, et al.
(författare)
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Atrial fibrillation management: a prospective survey in ESC Member Countries - The Euro Heart Survey on Atrial Fibrillation
- 2005
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 26:22, s. 2422-2434
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Tidskriftsartikel (refereegranskat)abstract
- Aims To describe atrial fibrillation (AF) management in member countries of the European Society of Cardiology (ESC) and to verify cardiology practices against guidelines. Methods and results Among 182 hospitals in 35 countries, 5333 ambulant and hospitalized AF patients were enrolled, in 2003 and 2004. AF was primary or secondary diagnosis, and was confirmed on ECG in the preceding 12 months. Clinical type of AF was reported to be first detected in 978, paroxysmal in 1517, persistent in 1167, and permanent in 1547 patients. Concomitant diseases were present in 90% of all patients, causing risk factors for stroke to be also highly prevalent (86%). As many as 69% of patients were symptomatic at the time of the survey; among asymptomatic patients, 54% were previously experienced symptoms. Oral anticoagulation was prescribed in 67 and 49% of eligible and ineligible patients, respectively. A rhythm control strategy was applied in 67% of currently symptomatic patients and in 44% of patients who never experienced symptoms. Conclusion This survey provides a unique snapshot of current AF management in ESC member countries. Discordance between guidelines and practice was found regarding several issues on stroke prevention and antiarrhythmic therapy.
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| 9. |
- Nieuwlaat, Robby, et al.
(författare)
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Should we abandon the common practice of withholding oral anticoagulation in paroxysmal atrial fibrillation?
- 2008
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 29:7, s. 915-922
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Tidskriftsartikel (refereegranskat)abstract
- Aims To assess the relation between the atrial fibrillation (AF) subtype and thrombo-embolic events. Methods and results The observational Euro Heart Survey on AF (2003-04) enrolled 1509 paroxysmal, 1109 persistent, and 1515 permanent AF patients, according to the 2001 American College of Cardiology, American Heart Association, and the European Society of Cardiology guidelines definitions. A 1 year follow-up was performed. Permanent AF patients had at baseline a worse stroke risk profile than paroxysmal and persistent AF patients. In paroxysmal AF, the risk for stroke, any thrombo-embolism, major bleeding and the combined endpoint of cardiovascular mortality, any thrombo-embolism, and major bleeding was comparable with persistent and permanent AF, in both univariable and multivariable analyses. Compared with AF patients without stroke, patients suffering from a stroke had a comparable frequency and duration of AF attacks, but tended to have a worse stroke risk profile at baseline. During 1 year following cardioversion, paroxysmal AF patients had a higher risk for stroke (P = 0.029) and any thrombo-embolism (P = 0.001) than persistent AF patients. Conclusion In the Euro Heart Survey, paroxysmal AF had a comparable risk for thrombo-embolic events as persistent and permanent AF. This observation strengthens the guideline recommendation not to consider the clinical AF subtype when deciding on anticoagulation.
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