| 1. |
- Liuba, Ioan, et al.
(author)
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Corrigendum for: Focal atrial tachycardia : increased electrogram fractionation in the vicinity of the earliest activation site. In Europace (ISSN 1099-5129), vol 10, issue 11, pg 1357
- 2008
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In: Europace. - : Oxford University Press (OUP). - 1099-5129 .- 1532-2092. ; 10:11, s. 1357-1357
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Journal article (other academic/artistic)abstract
- P values of P < 0.0001 should have been given in the abstractfor the increase within the region activated during the first15 ms of both the incidence of bipolar electrograms with multiplenegative deflections and of the incidence of unipolar electrogramswith multiple negative deflections.In the section ‘Characteristics of electrograms in theregion surrounding the earliest activation site and in the remainingatrium’ the P value for bipolar voltage should be P <0.0001, not P < 0001. In the same section the P value forthe decrease of unipolar and bipolar peak-to-peak voltage shouldbe P < 0.0001, not P < 0001.
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| 4. |
- Bollmann, Andreas, et al.
(author)
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Analysis of surface electrocardiograms in atrial fibrillation: techniques, research, and clinical applications
- 2006
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In: Europace. - : Oxford University Press (OUP). - 1532-2092. ; 8:11, s. 911-926
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Research review (peer-reviewed)abstract
- Atrial. fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Neither the natural history of AF nor its response to therapy is sufficiently predictable by clinical and echocardiographic parameters. The purpose of this article is to describe technical aspects of novel electrocardiogram (ECG) analysis techniques and to present research and clinical applications of these methods for characterization of both the fibrillatory process and the ventricular response during AF Atrial fibrillatory frequency (or rate) can reliably be assessed from the surface ECG using digital signal processing (extraction of atrial, signals and spectral analysis). This measurement shows large inter-individual variability and correlates well with intra-atriat cycle length, a parameter which appears to have primary importance in AF maintenance and response to therapy. AF with a tow fibrillatory rate is more likely to terminate spontaneously and responds better to antiarrhythmic drugs or cardioversion, whereas high-rate AF is more often persistent and refractory to therapy. Ventricular responses during AF can be characterized by a variety of methods, which include analysis of heart rate variability, RR-interval histograms, Lorenz plots, and non-linear dynamics. These methods have all shown a certain degree of usefulness, either in scientific explorations of atrioventricular (AV) nodal function or in selected clinical questions such as predicting response to drugs, cardioversion, or AV nodal modification. The role of the autonomic nervous system for AF sustenance and termination, as well as for ventricular rate responses, can be explored by different ECG analysis methods. In conclusion, non-invasive characterization of atrial fibrillatory activity and ventricular response can be performed from the surface ECG in AF patients. Different signal processing techniques have been suggested for identification of underlying AF pathomechanisms and prediction of therapy efficacy.
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| 5. |
- Bollmann, Andreas, et al.
(author)
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Atrial fibrillatory rate and risk of left atrial thrombus in atrial fibrillation.
- 2007
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In: Europace. - : Oxford University Press (OUP). - 1532-2092. ; 9:8, s. 6-621
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Journal article (peer-reviewed)abstract
- ims In atrial fibrillation (AF), a relation between electrocardiogram (ECG) fibrillatory wave amplitude and thrombus formation has been sought for long with conflicting results. In contrast, the possible relation between atrial fibrillatory rate obtained from the surface ECG and left atrial thrombus formation in patients with AF is unknown and was consequently evaluated in this study. Methods and results One-hundred and twenty-five patients (mean age 64 ± 12 years, 72% male) with persistent non-valvular AF (mean duration 28 ± 80 days) undergoing transesophageal echocardiography were studied. In all patients, standard 12-lead ECG recordings were acquired before the examination. Atrial fibrillatory rate was determined using spatiotemporal QRST cancellation and time–frequency analysis of lead V1. Atrial fibrillatory rate measured 401 ± 63 fibrillations per minute (fpm, range 235–566 fpm) and was related with age (R = −0.326, P < 0.001), ventricular rate (R = −0.202, P = 0.024), gender (407 ± 62 in males vs. 387 ± 64 fpm in females, P = 0.038) but not AF duration (R = 0.088, P = 0.374), presence of lone AF (408 ± 66 vs. 394 ± 58 fpm, P = 0.228), or beta-blocker or calcium channel blocker treatment (398 ± 63 vs. 405 ± 62 fpm, P = 0.556). Age was the only independent predictor of fibrillatory rate (B = −1.714, P < 0.001). In patients with left atrial thrombus (n = 10), spontaneous echo contrast (SEC) was more frequently present (70 vs. 29 %, p = 0.007) and left atrial appendage (LAA) outflow velocity was lower (26 ± 20 vs. 37 ± 15 cm/s, P = 0.012) than in patients without thrombus (n = 115). In contrast, mean fibrillatory rate, which showed a weak inverse correlation with LAA velocity (R = −0.118, P = 0.048) was not different between both groups (380 ± 56 vs. 403 ± 63 fpm, P = 0.226). Similarly, presence of thrombus and SEC combined was not related with fibrillatory rate. Conclusion Atrial fibrillatory rate obtained from surface ECG lead V1 is not a risk marker for left atrial thrombus formation in AF.
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| 6. |
- Bollmann, Andreas, et al.
(author)
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Atrial fibrillatory rate and risk of stroke in atrial fibrillation.
- 2009
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In: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 11, s. 582-586
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Journal article (peer-reviewed)abstract
- Aims In atrial fibrillation (AF), a relation between electrocardiogram (ECG) parameters such as fibrillatory wave amplitude and stroke has been sought with conflicting results. In this study, we tested the hypothesis that the atrial fibrillatory rate of surface ECG lead V1 is related to stroke risk and may consequently be helpful for identifying high-risk patients. Methods and results Atrial fibrillatory rate of 79 consecutive patients with AF and embolic stroke (age 83 +/- 7 years, 41% male) was compared with those of a matched AF population without stroke (n = 79). Atrial fibrillatory rate was determined from the surface ECG using spatiotemporal QRST cancellation and time-frequency analysis of lead V1. There was no significant difference in any clinical or echocardiographic variable in patients with stroke compared with AF controls without stroke. Atrial fibrillatory rate measured 373 +/- 55 fibrillations per minute (fpm; range 235-505 fpm) in the entire population. There was no fibrillatory rate difference between stroke patients (369 +/- 54 fpm, range 256-505 fpm) and AF controls without stroke (378 +/- 56 fpm, range 235-488 fpm). There was an inverse correlation between fibrillatory rate and age (R = -0.219, P = 0.006). Individuals aged >/=85 years had a significantly lower fibrillatory rate (356 +/- 44 fpm) than individuals aged 65-74 years (384 +/- 56 fpm, P = 0.033) and individuals aged 75-84 years (384 +/- 60 fpm, P = 0.016). In those subgroups, fibrillatory rates were, however, also similar in stroke patients and AF controls. Conclusion Atrial fibrillatory rate obtained from surface ECG lead V1 is not a risk marker for stroke in AF.
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| 7. |
- Bollmann, Andreas, et al.
(author)
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Fibrillatory rate response to candesartan in persistent atrial fibrillation.
- 2008
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In: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 10, s. 1138-1144
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Journal article (peer-reviewed)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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| 8. |
- Brignole, M, et al.
(author)
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Indications for the use of diagnostic implantable and external ECG loop recorders
- 2009
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In: Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology. - : Oxford University Press (OUP). - 1532-2092. ; 11:5, s. 671-687
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Journal article (peer-reviewed)
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| 9. |
- Camm, A J, et al.
(author)
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Conventional and dedicated atrial overdrive pacing for the prevention of paroxysmal atrial fibrillation: the AFTherapy study.
- 2007
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In: Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology. - : Oxford University Press (OUP). - 1532-2092. ; 9:12, s. 1110-8
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Journal article (peer-reviewed)abstract
- AIMS: This investigation was conducted to determine the effectiveness of several conventional overdrive pacing modalities (single rate and rate responsive pacing at various lower rates) and of four dedicated preventive pacing algorithms in the suppression of paroxysmal atrial fibrillation (AF). METHOD AND RESULTS: In this multi-centre, randomized trial, 372 patients with drug-refractory paroxysmal AF were enrolled. Patients received a dual-chamber pacing device capable of delivering conventional pacing therapy as well as dedicated AF prevention pacing therapies and to record detailed AF-related diagnostics. The primary endpoint was AF burden, whereas secondary endpoints were time to first AF episode and averaged sinus rhythm duration. During a conventional pacing phase, patients were randomized to single rate or rate-responsive pacing with lower rates of either 70 or 85 min(-1) or to a control group with single rate pacing at 40 min(-1). In the subsequent preventive pacing phase, patients underwent pacing at a lower rate of 70 min(-1) with or without concomitant application of four preventive pacing algorithms. A substantial amount of data was excluded from the analysis because of atrial-sensing artefacts, identified in the device-captured diagnostics. In the conventional pacing phase, no significant differences were found between various lower rates and the control group receiving single rate pacing at 40 min(-1) or between single rate and rate-responsive pacing. Patients receiving preventive pacing with all four therapies enabled had a similar AF burden compared with patients treated with conventional pacing at 70 min(-1) (P = 0.47). CONCLUSIONS: The results do not demonstrate a significant effect of conventional atrial overdrive pacing or preventive pacing therapies. However, the observations provided important information for further consideration with respect to the design and conduct of future studies on the effect of atrial pacing therapies for the reduction of AF.
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| 10. |
- Carlson, Jonas, et al.
(author)
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Can Orthogonal Lead Indicators of Propensity to Atrial Fibrillation be Accurately Assessed from the 12-Lead ECG?
- 2005
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In: Europace. - : Oxford University Press (OUP). - 1532-2092. ; 7:Suppl 2, s. 39-48
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Journal article (peer-reviewed)abstract
- Aims: When analyzing P-wave morphology, the vectorcardiogram(VCG) has been shown useful to identify indicators of propensity to atrial fibrillation (AF). Since VCG is rarely used in the clinical routine, we wanted to investigate if these indicators could be accurately determined in VCG derived from standard 12-lead ECG (dVCG).Methods: ECG and VCG recordings from 21 healthy subjects and 20 patients with a history of AF were studied. dVCG was calculated from ECG using the inverse Dower transform. Following signal averaging of P-waves, comparisons were madebetween VCG and dVCG, where three parameters characterizing signal shape and 15 parameters describing the P-wave morphology were used to assess the compatibility of the two recording techniques. The latter parameters were alsoused to compare the healthy and the AF groups.Results: After transformation, P-wave shape was convincingly preserved. P-wave morphology parameters were consistent within the respective groups when comparing VCG and dVCG, with better preservation observed in the healthy group.Conclusion VCG derived from routine 12-lead ECG may be a useful alternate method for studying orthogonal P-wave morphology.
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