| 1. |
- Bollmann, Andreas, et al.
(författare)
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Fibrillatory rate response to candesartan in persistent atrial fibrillation.
- 2008
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 10, s. 1138-1144
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Angiotensin-receptor blockers may exert favourable anti-arrhythmic effects in atrial fibrillation (AF), but their mechanisms are not fully understood. In this study, we tested the hypotheses that (i) candesartan reduces atrial fibrillatory rate and (ii) fibrillatory rate and its response to candesartan are related with the outcome of cardioversion. For this purpose, a post hoc subanalysis of the randomized, placebo-controlled CAPRAF (Candesartan in the Prevention of Relapsing Atrial Fibrillation) trial was performed. Methods and results Patients with AF undergoing electrical cardioversion were randomized to receive candesartan 8 mg once daily (n = 58) or matching placebo (n = 66) and no additional class I or III anti-arrhythmic drugs. Fibrillatory rate was determined from ECG lead V1 at baseline and at the day of cardioversion using spatiotemporal QRST cancellation and time-frequency analysis. The median time on treatment was 29 days. Candesartan reduced fibrillatory rate [399 +/- 48 vs. 388 +/- 49 fibrillations/min (fpm), P = 0.04], but not placebo (402 +/- 58 vs. 402 +/- 61 fpm, P = 0.986). Candesartan effects were only observed if the baseline fibrillatory rate was high [>420 fpm: 445 +/- 21 vs. 415 +/- 49 fpm, P = 0.006 vs. intermediate (360-420 fpm): 397 +/- 19 vs. 391 +/- 37 fpm, P = 0.351 vs. low (<360 fpm): 326 +/- 26 vs. 338 +/- 29 fpm, P = 0.179]. Cardioversion success was 100% in patients with an on-treatment rate <360 fpm vs. 83% in patients with higher rates (P = 0.02). Risk for AF recurrence was similar in patients with low (64%), intermediate (75%), or high on-treatment rates (63%, P = 0.446) and was also independent of candesartan effects on the fibrillatory rate. Conclusion In patients with persistent AF, candesartan decreases the fibrillatory rate, but this effect is restricted to patients with high baseline fibrillatory rates and is not associated with improved cardioversion outcome. Fibrillatory rates <360 fpm are associated with successful cardioversion, but not with AF recurrence.
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| 2. |
- Corino, Valentina D A, et al.
(författare)
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Circadian variation of variability and irregularity of heart rate in patients with permanent atrial fibrillation: Relation to symptoms and rate-control drugs.
- 2015
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Ingår i: American Journal of Physiology: Heart and Circulatory Physiology. - : American Physiological Society. - 1522-1539 .- 0363-6135. ; 309:12, s. 2152-2157
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to evaluate the diurnal variation of the variability and irregularity of the heart rate (HR) in patients with permanent atrial fibrillation (AF), with and without rate-control drugs. Thirty-eight patients with permanent AF were part of an investigator-blind cross-over study, comparing diltiazem, verapamil, metoprolol, and carvedilol. We analyzed five Holter recordings per patient: at baseline (no rate-control drug) and with each of the four drug regimens. HR, variability (standard deviation, pNN20, pNN50, pNN80, and rMSSD) and irregularity (approximate (APEn) and sample entropy) parameters were computed in 20-minute long non-overlapping segments. Circadian rhythmicity was evaluated using the cosinor analysis to each parameter series, that is characterized by the 24-h mean (MESOR) and the excursion over the mean (the amplitude). Arrhythmia-related symptoms were assessed by a questionnaire measuring symptoms severity (SS) and frequency (SF). HR and variability parameters showed a significant circadian variation in most patients, whereas only a small minority of the patients had circadian variation of irregularity parameters. The patients with circadian ApEn at baseline had more severe symptoms (SS = 9±4 vs. 6±5, p<0.05; circadian vs. non-circadian variation). All drugs decreased the MESOR of HR and increased the MESOR of variability parameters. Only carvedilol and metoprolol decreased the normalized amplitude over the 24-h of all parameters and HR. In conclusion, HR and RR variability parameters present a circadian variation in patients with permanent AF, whereas few patients demonstrated circadian fluctuations in irregularity parameters, suggesting different physiological mechanisms.
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| 3. |
- Corino, Valentina D.A., et al.
(författare)
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Non-invasive evaluation of the effect of metoprolol on the atrioventricular node during permanent atrial fibrillation
- 2014. - January
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Ingår i: Computing in Cardiology 2014. - : Oxford University Press (OUP). - 2325-8861. - 9781479943463 - 9781479943470 ; 41, s. 889-892
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Konferensbidrag (refereegranskat)abstract
- The aim of this study was to evaluate changes in AV nodal properties during administration of metoprolol, using a novel ECG-based method for parameter estimation. The AV nodal parameters account for the probability of an impulse not passing through the fast pathway, the absolute refractory periods of the slow and fast pathways (aRPs and aRPf), representing the functional refractory period, and related prolongation in the respective refractory periods. Twenty patients (age 71±8 years, 14 men) with permanent AF from the RATe control in Atrial Fibrillation (RATAF) database were included in this study. Recordings during baseline and metoprolol administration were analyzed. Furthermore, simulated RR series were generated mimicking metoprolol administration. During metoprolol administration, aRP was significantly prolonged in both pathways (aRPs: 342±39 vs. 408±81 ms, p<0.001; aRPf: 432±74 vs. 527±83 ms, p<0.001). Similar results were found for the simulated RR series: both aRPs and aRPf were significantly prolonged with metoprolol. The AV nodal parameters reflect expected changes after metoprolol administration, i.e., a prolongation in functional refractory period. The simulations suggest that aRP may serve as an estimate of the functional refractory period.
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| 4. |
- Corino, Valentina D. A., et al.
(författare)
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Rate-Control Drugs Affect Variability and Irregularity Measures of RR Intervals in Patients with Permanent Atrial Fibrillation
- 2015
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Ingår i: Journal of Cardiovascular Electrophysiology. - : Wiley. - 1540-8167 .- 1045-3873. ; 26:2, s. 137-141
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Tidskriftsartikel (refereegranskat)abstract
- Heart Rate Variability and Irregularity During AF IntroductionIrregularity measures have been suggested as risk indicators in patients with atrial fibrillation (AF); however, it is not known to what extent they are affected by commonly used rate-control drugs. We aimed at evaluating the effect of metoprolol, carvedilol, diltiazem, and verapamil on the variability and irregularity of the ventricular response in patients with permanent AF. Methods and ResultsSixty patients with permanent AF were part of an investigator-blind cross-over study, comparing 4 rate-control drugs (diltiazem, verapamil, metoprolol, and carvedilol). We analyzed five 20-minute segments per patient: baseline and the 4 drug regimens. On every segment, heart rate (HR) variability and irregularity of RR series were computed. The variability was assessed as standard deviation, pNN20, pNN50, pNN80, and rMSSD. The irregularity was assessed by regularity index, approximate (ApEn), and sample entropy. A significantly lower HR was obtained with all drugs, the HR was lowest using the calcium channel blockers. All drugs increased the variability of ventricular response in respect to baseline (as an example, rMSSD: baseline 171 47 milliseconds, carvedilol 229 +/- 58 milliseconds; P < 0.05 vs. baseline, metoprolol 226 +/- 66 milliseconds; P < 0.05 vs. baseline, verapamil 228 +/- 84; P < 0.05 vs. baseline, diltiazem 256 +/- 87 milliseconds; P < 0.05 vs. baseline and all other drugs). Only -blockers significantly increased the irregularity of the RR series (as an example, ApEn: baseline 1.86 +/- 0.13, carvedilol 1.92 +/- 0.09; P < 0.05 vs. baseline, metoprolol 1.93 +/- 0.08; P < 0.05 vs. baseline, verapamil 1.86 +/- 0.22 ns, diltiazem 1.88 +/- 0.16 ns). ConclusionModification of AV node conduction by rate-control drugs increase RR variability, while only -blockers affect irregularity.
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| 5. |
- Freedman, Ben, et al.
(författare)
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Screening for Atrial Fibrillation A Report of the AF-SCREEN International Collaboration
- 2017
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Ingår i: Circulation. - : LIPPINCOTT WILLIAMS & WILKINS. - 0009-7322 .- 1524-4539. ; 135:19, s. 1851-
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Tidskriftsartikel (refereegranskat)abstract
- Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country-and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.
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| 6. |
- Holmqvist, Fredrik, et al.
(författare)
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Abnormal atrial activation in young patients with lone atrial fibrillation.
- 2011
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; Okt, s. 188-192
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Tidskriftsartikel (refereegranskat)abstract
- Aims Patients with a history of atrial fibrillation (AF) have previously been shown to have altered atrial conduction, as seen non-invasively using signal-averaged P-wave analysis. However, little is known about the P-wave morphology in patients in the early phases of AF with structurally normal hearts. Methods and results Thirty-six patients with lone AF were included before the age of 40 years (34 ± 4 years, 34 men) and compared with age- and gender-matched control subjects. Standard 12-lead electrocardiogram (ECG) was recorded for at least 10 s. P-wave morphology and duration were estimated using signal-averaged P-wave analysis. Echocardiography was performed in association with the ECG recording. Heart rate (67 ± 13 vs. 65 ± 7 b.p.m., P = 0.800) and PQ-interval (163 ± 16 vs. 164 ± 23 ms, P = 0.629) were similar in AF cases and controls, as was P-wave duration (136 ± 13 vs. 129 ± 13 ms, P = 0.107). The distribution of P-wave morphology differed between the AF cases and controls [33/58/0/8 vs. 75/25/0/0% (Type 1/Type 2/Type 3/atypical), P = 0.001], with a larger proportion of patients with AF exhibiting signs of impaired interatrial conduction. Conclusion A significant difference in P-wave morphology distribution was seen between patients with early-onset, lone paroxysmal AF and age- and gender-matched healthy control subjects. This finding indicates that alterations in atrial electrophysiology are common in the early stage of the arrhythmia, and since it occurs in young patients without co-morbidity may well be the cause rather than the consequence of AF.
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| 7. |
- Roselli, Carolina, et al.
(författare)
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Multi-ethnic genome-wide association study for atrial fibrillation
- 2018
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 50:9, s. 1225-1233
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Tidskriftsartikel (refereegranskat)abstract
- Atrial fibrillation (AF) affects more than 33 million individuals worldwide(1) and has a complex heritability(2). We conducted the largest meta-analysis of genome-wide association studies (GWAS) for AF to date, consisting of more than half a million individuals, including 65,446 with AF. In total, we identified 97 loci significantly associated with AF, including 67 that were novel in a combined-ancestry analysis, and 3 that were novel in a European-specific analysis. We sought to identify AF-associated genes at the GWAS loci by performing RNA-sequencing and expression quantitative trait locus analyses in 101 left atrial samples, the most relevant tissue for AF. We also performed transcriptome-wide analyses that identified 57 AF-associated genes, 42 of which overlap with GWAS loci. The identified loci implicate genes enriched within cardiac developmental, electrophysiological, contractile and structural pathways. These results extend our understanding of the biological pathways underlying AF and may facilitate the development of therapeutics for AF.
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| 8. |
- Sandberg, Frida, et al.
(författare)
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Drug effect evaluation during permanent atrial fibrillation using an AV-node model
- 2013
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Ingår i: Computing in Cardiology 2013, CinC 2013. - 9781479908844 ; 40, s. 1243-1246
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Konferensbidrag (refereegranskat)abstract
- The purpose of the present study is to evaluate the effect of rate control drugs on the AV node characteristics during atrial fibrillation (AF) using a model-based approach. A statistical model of the AV nodal function is employed, defined by parameters which characterize the arrival rate of atrial impulses, the refractoriness of the fast and the slow AV-nodal pathway and the probability of atrial impulse to pass through either of the two pathways. The RATAF (RATe control in Atrial Fibrillation) study database consists of recordings from 60 patients with permanent AF at baseline and on treatment with metoprolol, verapamil, diltiazem and carvedilol, respectively. The resulting model parameter estimates indicate that the refractory period of the slow pathway as well as that of the fast pathway increased significantly during treatment with all four drugs. The results suggest that the proposed AV-node model can be used for non-invasive evaluation of the effect of rate control drugs.
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| 9. |
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| 10. |
- Seifert, Mariam B., et al.
(författare)
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Genetic variants on chromosomes 7p31 and 12p12 are associated with abnormal atrial electrical activation in patients with early-onset lone atrial fibrillation
- 2019
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Ingår i: Annals of Noninvasive Electrocardiology. - : Wiley. - 1082-720X .- 1542-474X. ; 24:6
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Tidskriftsartikel (refereegranskat)abstract
- Background: Abnormal P-wave morphology (PWM) has been associated with a history of atrial fibrillation (AF) in earlier studies. Although lone AF is believed to have substantial genetic basis, studies on associations between single nucleotide polymorphisms (SNP) linked to lone AF and PWM have not been reported. We aimed to assess whether SNPs previously associated with lone AF (rs2200733, rs13376333, rs3807989, and rs11047543) are also linked to P-wave abnormalities. Methods: Four SNPs were studied in 176 unrelated individuals with early-onset lone AF (age at onset <50 years), median age 38 years (19–63 years), 149 men. Using sinus rhythm ECG, orthogonal PWM was classified as Type 1—positive in leads X and Y and negative in lead Z, Type 2—positive in leads X and Y and biphasic (−/+) in lead Z, Type 3—positive in lead X and biphasic in lead Y (+/−), and the remaining as atypical. Results: Two SNPs were found to be significantly associated with altered P-wave morphology distribution: rs3807989 near the gene CAV1/CAV2 and rs11047543 near the gene SOX5. Both SNPs were associated with a higher risk of non-Type 1 P-wave morphology (rs3807989: OR = 4.8, 95% CI = 2.3–10.2, p < 0.001; rs11047543: OR = 4.7, 95% CI = 1.1–20.5, p = 0.04). No association was observed for rs2200733 and rs13376333. Conclusion: In this study, the two variants rs3807989 and rs11047543, previously associated with PR interval and lone AF, were associated with altered P-wave morphology distribution in patients with early-onset lone AF. These findings suggest that common genetic variants may modify atrial conduction properties.
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| 11. |
- Sørensen, Eivind, et al.
(författare)
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Left atrial dyssynchrony in veteran endurance athletes with and without paroxysmal atrial fibrillation
- 2023
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Ingår i: Echocardiography. - 0742-2822. ; 40:7, s. 679-686
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Tidskriftsartikel (refereegranskat)abstract
- Background: Prolonged endurance exercise increase the risk of atrial fibrillation (AF) in men. Functional parameters may help separate physiological from pathological atrial remodeling in athletes. LA mechanical dispersion (LA MD) is associated with AF in the general population, but the associations between prolonged exercise, LA MD and AF are not known. Purpose: To describe LA MD in veteran athletes with and without paroxysmal AF (pAF) and to investigate LA MD's ability to identify veteran athletes with pAF. Methods: Two hundred and ninety-three men, skiers with (n = 57) and without (n = 87) pAF, and controls with (n = 61) and without pAF (n = 88) underwent an echocardiographic exam in sinus rhythm. LA reservoir strain (LASr) was measured, and LA MD defined as the standard deviation of time-to-peak strain (SD-TPS). Results: Skiers (mean age 70.7 ± 6.7 years) reported an average of 40–50 years of endurance exercise. LA volumes were associated with pAF and athletic status (p <.001). SD-TPS was associated with pAF (p <.001) but not athletic status (p =.173). We found no significant trend between years of exercise and SD-TPS in individuals without AF (p =.893). SD-TPS did not add incremental value in identifying athletes with pAF in addition to clinical markers, QRS width, LA volume, and LASr (p =.056). Conclusion: LA MD was associated with pAF regardless of athletic status but not related to years of endurance exercise, suggesting LA MD could be a promising marker of pathological atrial remodeling in athletes. However, we found no incremental value of LA MD identifying athletes with pAF when LASr was included in the model.
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| 12. |
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