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Irregular heartbeats and different forms of ventricular ectopic activity are a common occurrence among
elite athletes with high contractile cardiac capacity. At the same time, experiments demonstrated that the electrical stimulation threshold, causing ventricular fibrillation, increases during adaptation to physical exe
rcise, without the increase in the contractile cardiac capacity. The research purpose is to examine the dependence of ventricular fibrillation threshold and contractile cardiac capacity on intensity and duration
of swimming sessions, as well as duration of the training period. Female Wistar rats were assigned to five groups: sedentary (S), training 1 (T1, low intensity), training 2 (T2, moderate intensity), training 3 (T3, long-term), training 4 (T4, exhaustive). At the end of the experimental period, the rats were anesthetized and their ventricles irritated with rectangular pulses of 10 ms duration, to determine the minimum current causing ventricular fibrillation. The cardiac capacity was assessed by the maximum pressure in the left ventricle, at full aortic-cross clamping. The ventricular fibrillation threshold was increased by 60% in T1, 57.5% in T2 and 74% in T3, but no difference in T4 was observed, compared with S. The pick pressure in the left ventricle after aortic cross-clamping in T1 and T2 was not enhanced, compared with S; in T3 and T4, however, it was significantly increased. Physical exercise training changed the ventricular fibrillation
threshold and cardiac contractile capacity, independently of the intensity of exercise. The rise of the ventricular fibrillation threshold and its contractile capacity can be demonstrated during a long adaptation to moderate-term sessions of aerobic exercises.
  • 1. Chinkin A.S., Shimkovich M.V. Effect of adaptation to physical exercise on adrenergic reactivity of isolated rat atrium. Bull. Experim. Biol. and Med. 1987;104(7) :23-26.
  • 2. Crawford M.H., O‘Rourke R.A. The athletic heart. Adv. Intern. Med Chicago-London. 1979; 24:311-29.
  • 3. Ector H., Bourgois J., Verlinden M. Bradicardia, ventricular pauses, syncope and sports. Lancet 1984;03:591-94.
  • 4. Green L.N., Cohen S.I., Kurland G. Fatal myocardial infarction in marathon racing. Ann. Intern. Med. 1976;84:704-06.
  • 5. Guski H., Meerson F.S., Wassiliev G. Comparative study of ultrastructure and function of the rat heart hypertrophied by exercise or hypoxia. Exp. Pathol. 1981;20:108-20.
  • 6. Hull S.S., Vanoli E., Adamson P.B., Verrier P.L. Exercise training confers anticipatory protection from sudden death during acute myocardial ischemia. Circulation. 1994;89:542-52.
  • 7. Kammereit A., Medugoras I. Mechanics of isolated ventricular myocardium of rats conditions by physical training. Basic Res. Cardiol. 1975;70(5):495-507.
  • 8. Kapelko V.I., Giber L.M. Reaction of the heart to the functional load adapted to physical stress in rats. Sechenov Physiol. J. 1977;63(5):597-99.
  • 9. Krames B.B., Nothup D.M. Isometric tension development in the hypertrophied heart. Fed. Proc. 1984;32(2):359-60.
  • 10. Marijon E., Tafflet M., Celermajer D.C. et al. Sports-related sudden death in the general population. Circulation. 2011;124(6):672-84.
  • 11. Maron B.J., Doerer J.J., Hass T.S. et al. Sudden deaths in young competitive athletes: analysis of 1866 deaths in the United States, 1980-2006. 2009;119(8):1085-92.
  • 12. Meerson F.Z., Ustinova E.E., Chinkiin A.S. Effect of preliminary adaptation to moderate and intensive physical exercises on electrical stability and contractile function of the heart in experimental myocardial infarction. Cardiology. 1987;27(3):78-82.
  • 13. Natan D., Da Silva J.R., Tiago F., Ursula P.R. et al. Swimming training in rats increases cardiac MicroRNA-126 expression and angiogenesis. Med. and Sci. in Sports and Exerc. 2012;44(8):1453-62.
  • 14. Noakes T., Higginson L., Opie L. Physical training increases ventricular fibrillation thresholds of isolated rat hearts during normoxia, hypoxia and regional ischemia. Circulation. 1983;67(1):24-30.
  • 15. Sitdikov F.G., Chinkin S.S., Chinkin A.S. Content and synthesis of catecholamines in the adrenal glands of rats at different levels of muscle activity. In: Catecholamines and corticosteroids during muscular activity. Tartu. 1987;7:30-31.
  • 16. Tibbits G.T., Nagamoto T. Cardiac sarcolemma: compositional adaptation to exercise. Science. 1984;13(4513):1271-1273.
  • 17. Wisshoff U., Loennchen J.P., Flack G., Beisvag V. Increased contractility and calcium sensitivity in cardiac myocites isolated from endurance trained rats. Circul. Res. 2001;50:495-508.
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