| 1. |
- Corino, Valentina D A, et al.
(författare)
-
Statistical modeling of atrioventricular nodal function during atrial fibrillation : An update
- 2013
-
Ingår i: BIOSIGNALS 2013 - Proceedings of the International Conference on Bio-Inspired Systems and Signal Processing. - 9789898565365 ; , s. 25-29
-
Konferensbidrag (refereegranskat)abstract
- This paper introduces a number of advancements of our recently proposed model of atrioventricular (AV) node function during atrial fibrillation (AF). The model is defined by parameters characterizing the arrival rate of atrial impulses, the probability of an impulse choosing either one of the two AV nodal pathways, the refractory periods of these pathways, and their prolongation. In the updated model, the characterization of AV nodal pathways is made more detailed and the number of pathways is determined by the Bayesian information criterion. The performance is evaluated on ECG data acquired from twenty-five AF patients during rest and head-up tilt test. The results show that the refined AV node model provides significantly better fit than did the original model. During tilt, the AF frequency increased (6.25 ±0.58 Hz vs. 6.32 ±0.61 Hz, p < 0.05, rest vs. tilt) and the prolongation of the refractory periods decreased for both pathways (slow pathway: 0.23 ±0.20 s vs. 0.11 ±0.10 s, p < 0.001, rest vs. tilt; fast pathway: 0.24±0.31 s vs. 0.16±0.19 s, p < 0.05, rest vs. tilt). These results show that AV node characteristics can be assessed noninvasively for the purpose of quantifying changes induced by autonomic stimulation.
|
|
| 2. |
- Goya-Esteban, Rebeca, et al.
(författare)
-
Seven-day analysis of atrial fibrillation and circadian rhythms
- 2013
-
Ingår i: BIOSIGNALS 2013 - Proceedings of the International Conference on Bio-Inspired Systems and Signal Processing. - 9789898565365 ; , s. 20-24
-
Konferensbidrag (refereegranskat)abstract
- In the present work, f-wave morphology is characterized by principal component analysis and a novel temporal parameter defined by the cumulative normalized variance of the 3 largest principal components (r3). The 7-day behavior of persistent atrial fibrillation (AF) was studied in 9 patients using r3, AF frequency, and sample entropy (SampEn). Detection of circadian rhythms depended on the parameter considered: rhythms were found in 6 (r3, SampEn) and 5 (AF frequency) patients, but interestingly not always in the same patients. Two patients had significant circadian rhythm in all parameters. When a circadian rhythm was significantly present in 7 days, it was usually only significantly present in some of the 24-h segments. It is concluded that detailed AF characterization can be achieved with complementary parameters.
|
|
