31. |
|
|
32. |
- Meurling, Carl, et al.
(författare)
-
Diurnal variations of the dominant cycle length of chronic atrial fibrillation
- 2001
-
Ingår i: American Journal of Physiology: Heart and Circulatory Physiology. - 1522-1539. ; 280:1, s. 401-406
-
Tidskriftsartikel (refereegranskat)abstract
- High-resolution digital Holter recording was carried out in 21 patients (15 men, 64 +/- 12 yr) with chronic atrial fibrillation. Dominating atrial cycle length (DACL) was derived by frequency domain analysis of QRST-reduced electrocardiograms. Daytime mean DACL was 150 +/- 17 ms, and nighttime mean was 157 +/- 22 ms (P = 0. 0002). Diurnal fluctuation in DACL differed among patients: it tended to be virtually absent in those with a short mean DACL, but in those with longer DACL the night-day difference was as much as 23 ms (R = 0.72, P < 0.001, correlation of mean DACL to night-day difference). Mean DACL also correlated with ventricular cycle length (R = 0.40, P < 0.001), particularly at night (r = 0.49). The shorter cycle lengths found in this study during the day are consistent with sympathetic and/or other physiological modulation, but since increased vagal tone shortens atrial refractoriness in most models, parasympathetic influences are not likely to play a major role. Alternatively, atrial effective refractory period may not be the sole determinant of atrial cycle length during atrial fibrillation.
|
|
33. |
|
|
34. |
|
|
35. |
|
|
36. |
|
|
37. |
|
|
38. |
|
|
39. |
|
|
40. |
|
|