Esophageal and Intracardiac Electrograms, Intracardiac Mapping
P-Wave Signal Averaged ECG
Frequency Analysis of Fibrillation
Body Surface Potential Mapping
Magnetocardiography
ECG-guided AF Treatment Strategies
The network’s research strategy involves combining highly-specialized skills of different research groups with complementary interests and expertise covering diverse areas of today’s electrocardiographic and magnetocardiographic AF research.
The different research teams have developed and successfully applied the following relevant, unique methodologies and approaches that will also be employed in this project.
Using different filter settings, different electrode positions and analysis techniques of single and multiple signals, atrial activation can be characterized, and conduction defects can be localized from esophageal recordings (1) as well as from intracardiac recordings obtained during invasive electrophysiologic studies using different cardiac mapping systems (2-4). The left atrium and great cardiac veins are areas of special interest for induction and maintenance of AF.
Electroanatomic mapping using Carto-system creates three-dimensional intracavitary maps of cardiac chambers providing information on local activation times and signal characters. While applied in clinical arrhythmia therapy the Carto-system yields accurate reference data for development of non-invasive electromagnetic mapping techniques. Non-contact mapping with EnSite system, also applied in clinical cardiology, allows determination of calculated intra-atrial potentials and activation sequences from basal rhythm and short-lasting arrhythmias.
P-Wave Signal Averaged ECG
Teams in Lund have developed analysis of P-wave morphology which allows discrimination between recordings from healthy subjects and those predisposed to AF by identifying markers of interatrial conduction defects such as P-wave configuration in Z orthogonal lead (anterior-posterior vector), delayed atrial activation by X-lead or double-peaked morphology of spatial magnitude (5).
Atrial activity during AF can be characterized using spectral analysis techniques of the surface ECG after subtraction of averaged QRST complexes (6). This so-called FAF-ECG has been introduced in parallel by network teams in Lund and Magdeburg and provides non-invasive markers of atrial electrophysiology during AF (3,7). More recently, a time-frequency approach has been developed by which the spectral profile, second-to-second variations in fundamental frequency and waveform morphology can be characterized (8, 9).
Body Surface Potential Mapping
Body Surface Potential Mapping (BSPM) is an electrocardiographic technique based on the acquisition of multiple signals at different locations over the chest. BSPM has been previously applied to analysis of micropotentials in post infarction arrhythmia patients (10). In the study of myocardial infarction BSPM has shown its superiority to standard 12-lead ECG recordings as it reveals more diagnostic information and most importantly adds the spatial perspective to electrocardiography (11). Application of the BSPM technique during AF is a new field of investigation, allowing more comprehensive view by enhancing information on locality (12,13).
Magnetocardiography
Magnetocardiographic (MCG) mapping is a new non-invasive technique to analyze cardiac electromagnetic signals. MCG provides high spatial accuracy, low dependence on intervening tissue, and high signal-to-noise ratio. MCG has been applied in the analysis of ventricular late fields showing better accuracy than late potentials to reveal propensity to ventricular arrhythmias, in localizing arrhythmia foci and in detection of myocardial ischemia (14,15). Recently the MCG method has been developed in Helsinki to analyze atrial activity providing information on distribution of atrial electric potentials and propagation of atrial activation (16,17).
ECG-guided AF Treatment Strategies
Prevention and reversal of atrial remodeling using verapamil (18, 19) as well as its concomittant use to enhance cardioversion outcome (20) has been analysed. Clinical-decision-making based on “Frequency Analysis of Fibrillation” for monitoring (18, 21) and predicting antiarrhythmic drug effects (3, 22), AF recurrence following cardioversion (23) or prediction of spontaneous AF termination (24) are examples for guided AF therapy (as opposed to empirical) (25).
References
1. Pehrson S, Holm M, Meurling C, Ingemansson M, Smideberg B, Sornmo L, Olsson SB. Non-invasive assessment of magnitude and dispersion of atrial cycle length during chronic atrial fibrillation in man. Eur Heart J. 1998;19:1836-44.
2. Holm M, Johansson R, Brandt J, Luhrs C, Olsson SB. Epicardial right atrial free wall mapping in chronic atrial fibrillation. Documentation of repetitive activation with a focal spread--a hitherto unrecognised phenomenon in man. Eur Heart J. 1997;18:290-310.
3. Bollmann A, Kanuru NK, McTeague KK, Walter PF, DeLurgio DB, Langberg JJ. Frequency analysis of human atrial fibrillation using the surface electrocardiogram and its response to ibutilide. Am J Cardiol. 1998;81:1439-45.
4. Holm M, Pehrson S, Ingemansson M, Sornmo L, Jahansson R, Sandhall L, Sunemark M, Smideberg B, Olsson C, Olsson SB. Non-invasive assessment of the atrial cycle length during atrial fibrillation in man: introducing, validating and illustrating a new ECG method. Cardiovasc Res. 1998;38:69-81.
5. Platonov PG, Yuan S, Hertervig E, Kongstad O, Roijer A, Vygovsky AB, Chireikin LV, Olsson SB. Further evidence of localized posterior conduction delay in lone paroxysmal atrial fibrillation. Europace. 2001;3:100-107.
6. Stridh M, Sornmo L. Spatiotemporal QRST cancellation techniques for analysis of atrial fibrillation. IEEE Trans Biomed Eng. 2001;48:105-11
7. Holm M. Chronic atrial fibrillation in man. Activation, organisation and characterisation. Dissertation. Lund University. 1997
8. Stridh M, Sornmo L, Meurling CJ, Olsson SB. Characterization of atrial fibrillation using the surface ECG: time-dependent spectral properties. IEEE Trans Biomed Eng. 2001;48:19-27
9. Stridh M, Sornmo L, Meurling CJ, Olsson SB. Sequential characterization of atrial tachyarrhythmias based on ECG time-frequency analysis. IEEE Trans Biomed Eng. 2004;51:100-14
10. Korhonen P, Tierala I, Simelius K, Väänänen H, Mäkijärvi M, Nenonen J, Katila T, Toivonen L. Late QRS activity in signal-averaged magnetocardiography, body surface potential mapping, and orthogonal ECG in postinfarction ventricular tachycardia patients. Annals of Noninvasive Electrocardiology. 2002;7(4):389-98.
11. Vesterinen P, Hanninen H, Karvonen M, Lauerma K, Holmstrom M, Makijarvi M, Vaananen H, Nenonen J, Katila T, Toivonen L. Temporal analysis of the depolarization wave of healed myocardial infarction in body surface potential mapping. Ann Noninvasive Electrocardiol. 2004;9:234-42
12. Pesola K, Nenonen J, Fenici R, Lötjönen J, Mäkijärvi M, Fenici P, Korhonen P, Lauerma K, Valkonen M, Toivonen L, Katila T. Bioelectromagnetic localization of a pacing catheter in the heart. Physics in Medicine & Biology. 1999;44(10):2565-78.
13. Jokiniemi T, Simelius K, Nenonen J, Tierala I, Toivonen L, Katilal T. Baseline reconstruction for localization of rapid ventricular tachycardia from body surface potential maps. Physiological Measurement. 2003;24(3):641-51.
14. Karvonen M, Oikarinen L, Takala P, Kaartinen M, Rossinen J, Hanninen H, Montonen J, Nenonen J, Makijarvi M, Keto P, Toivonen L, Nieminen MS, Katila T. Magnetocardiographic indices of left ventricular hypertrophy. J Hypertens. 2002;20:2285-92
15. Korhonen P, Montonen J, Endt P, Makijarvi M, Trahms L, Katila T, Toivonen L. Magnetocardiographic intra-QRS fragmentation analysis in the identification of patients with sustained ventricular tachycardia after myocardial infarction. Pacing Clin Electrophysiol. 2001;24:1179-86.
16. Koskinen R, Väänänen H, Lehto Mika, Montonen J, Lehtonen L, Voipio-Pulkki L-M, Toivonen L. Abnormalities in magnetocardiographic atrial signals in patients with focally-triggered lone atrial fibrillation [abstract]. J Am Coll Cardiol 2004: 43 (5, Suppl A): 142A
17. Nenonen J, Montonen J, Koskinen R. Surface Gradient Analysis of Atrial Activation from Magnetocardiographic Maps. International Journal of Bioelectromagnetism 2003; 5 (1):98-99.
18. Meurling CJ, Ingemansson MP, Roijer A, Carlson J, Lindholm CJ, Smideberg B, Sornmo L, Stridh M, Olsson SB. Attenuation of electrical remodelling in chronic atrial fibrillation following oral treatment with verapamil. Europace. 1999;1:234-41.
19. Bollmann A, Sonne K, Esperer HD, Toepffer I, Klein HU. Patients with persistent atrial fibrillation taking oral verapamil exhibit a lower atrial frequency on the ECG. Ann Noninvasive Electrocardiol. 2002;7:92-7
20. Lindholm CJ, Fredholm O, Moller SJ, Edvardsson N, Kronvall T, Pettersson T, Firsovaite V, Roijer A, Meurling CJ, Platonov PG, Olsson SB. Sinus rhythm maintenance following DC cardioversion of atrial fibrillation is not improved by temporary precardioversion treatment with oral verapamil. Heart. 2004;90:534-8.
21. Husser D, Stridh M, Sornmo L, Geller C, Klein HU, Olsson SB, Bollmann A. Time-frequency analysis of the surface electrocardiogram for monitoring antiarrhythmic drug effects in atrial fibrillation. Am J Cardiol. 2005;in press.
22. Bollmann A, Binias KH, Toepffer I, Molling J, Geller C, Klein HU. Importance of left atrial diameter and atrial fibrillatory frequency for conversion of persistent atrial fibrillation with oral flecainide. Am J Cardiol. 2002;90:1011-14
23. Bollmann A, Husser D, Steinert R, Stridh M, Soernmo L, Olsson SB, Polywka D, Molling J, Geller C, Klein HU. Echo- and electrocardiographic predictors for atrial fibrillation recurrence following cardioversion. J Cardiovasc Electrophysiol. 2003;14:S162-S165
24. Bollmann A, Sonne K, Esperer HD, Toepffer I, Langberg JJ, Klein HU. Non-invasive assessment of fibrillatory activity in patients with paroxysmal and persistent atrial fibrillation using the Holter ECG. Cardiovasc Res. 1999;44:60-6
25. Bollmann A. Quantification of electrical remodeling in human atrial fibrillation. Cardiovasc Res. 2000;47:207-209
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Last modified: 2010-04-26
