[Paroxysmal atrial fibrillation: study of the pattern of onset using dynamic electrocardiography].

UNLABELLED: We have examined 24 hours ECG Holter recordings of 22 patients without any organic heart disease and with recurrent episodes of paroxysmal atrial fibrillation (PAF) to check the possible sympatho-vagal influence on spontaneous initiation. Patients were divided into 3 groups according to average heart rate (HR) during the 24 hours recording and to the mode of onset of the arrhythmia: sympathetic (only diurnal episodes, HR greater than or equal to 75 b/min before the onset of the episode, average 24 hours HR greater than or equal to 80 b/min, progressive or sudden shortening of sinusal cycle before the onset), vagal (only nocturnal episodes, HR less than or equal to 60 b/min before the onset, average 24 hours HR less than or equal to 60 b/min, progressive or sudden lengthening of sinusal cycle before the onset of the episode) or "others" who did not show the aforementioned characteristics.

RESULTS

there are not only 2 types of patients under prevalent sympathetic or vagal control but even patients who show mixed patterns; in the sympathetic group there are significant differences between ectopic atrial beats (EAB) that start a PAF and isolated EAB in: prematurity index (0.51 +/- 0.11 vs 0.45 +/- 0.07; p less than 0.001) coupling time (381 +/- 36 ms vs 419 +/- 48 ms; p less than 0.005), sinus cycle length (PP) before the onset of the arrhythmia (761 +/- 192 ms vs 950 +/- 175 ms; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)