[Role of geomagnetic field in development of biorhythm profile of ventricular arrhythmia onset].

To clarify the role of geomagnetic field (GMF) on development of circadian profile of life-threatening ventricular tachycardia 13 children aged 9-14 years underwent 24-h Holter monitoring (Oxford Medilog Optima, Great Britain). 8 children had Romano-Ward syndrome, catecholaminergic bidirectional ventricular tachycardia (group 1), 5 children had sick sinus syndrome (group 2). In patients from group 1 "torsade de pointes", episodes of polymorphic bidirectional and monomorphic ventricular tachycardia, frequent ventricular extrasystole were recorded in 1, 5 and 2 patients, respectively. Patients of group 2 had asystole up to 5 seconds. Circadian pattern of arrhythmia and heart rate variability BPC (mean, SDNN, SDAN-N-i, SDNN-i, rMSSD, pNN50) were compared to 3-hour values of Ap(Ar)-index of geomagnetic activity in the examination day in Moscow with estimation of the correlation coefficient (r). Changes in GMF were not correlated with BPC in group 1 children. Frequency of arrhythmia and Ap-index were related in 5 of 8 children in group 1: r from +0.67 (p < 0.05) to +0.97 (p < 0.01). 2 children from group 1 had no correlation between frequency of tachyarrhythmia and dynamics of GMF but demonstrated relation between frequency of arrhythmia and mean value of RR interval (Mean): r-0.73 (p < 0.05) and 0.71 (p < 0.05). Patients of group 2 exhibited no significant correlation between the frequency and duration of rhythmic pauses and GMF changes. This may be due to strong dependence of bradyarrhythmia circadian profile on endogenic circadian endocrine rhythms of parasympathetic regulation. The conclusion was made on possible effect of GMF on provocation and formation of circadian profile of life-threatening ventricular tachyarrhythmia in children and adolescents. Sympathetic activation may participate in realization of this effect.