Circadian Modulation of Atrial Cycle Length in Human Chronic Permanent Atrial Fibrillation: A Noninvasive Assessment Using Long-Term Surface ECG

Autor: S. Bertil Olsson, Antoine Leenhardt, Stéphane Cosson, Pierre Maison-Blanche, Fabio Badilini, Philippe Coumel
Rok vydání: 2000
Předmět:
Zdroj: Annals of Noninvasive Electrocardiology. 5:270-278
ISSN: 1542-474X
1082-720X
DOI: 10.1111/j.1542-474x.2000.tb00398.x
Popis: Objectives: Short-term autonomic influences on the electrophysiological properties (EP) of the atrial myocardium are well known, but the role of long-term sympathovagal influences on EP is less clear. This study aimed at finding if a circadian pattern could be identified in atrial EP, using the fibrillatory wave (F wave) of surface ECG recordings as a surrogate of atrial refractoriness in patients with chronic permanent atrial fibrillation (AFib). Methods: 24-hour two-channel Holter ECG were obtained in 20 consecutive patients (mean age 70 ± 8 years) with nonvalvular, chronic and permanent AFib, free of antiarrhythmic agents except digoxin. Digitized ECG were analyzed by a custom software. After QRST substraction of detected complexes, the residual F waves (5-min duration) were computed by a Fourier algorithm. The dominant frequency peak of the power spectrum obtained has been shown to correspond to the dominant atrial cycle length (DACL). 24-hour recordings were analyzed separately during the day (8 active and awake consecutive hours) and at night (4 resting and asleep consecutive hours), and DACL was calculated hourly for each diurnal and nocturnal periods. Results: Spectra could be reliably studied in 17 patients (85%). The DACL showed a significant circadian pattern with a mean 3.3% increase, from 151 ms in the diurnal period to 156 ms at night (P < 0.001). A significant positive relation was found between circadian day-night changes of DACL and the baseline DACL value (P < 0.05). Mean ventricular heart rate decreased from 87 beats/min during the diurnal period to 71 beats/min at night (P < 0.001). Conclusion: Spectral analysis of the F wave can be successfully achieved from long-term Holter recordings. In chronic permanent AFib, the DACL still shows a circadian rhythmicity with an increase from day to night. In addition to atrial refractoriness, the amplitude of DACL circadian modulation could represent a new index of atrial electrical remodeling.
Databáze: OpenAIRE
Externí odkaz: