1 [email protected] Computer simulations of propagation and reentry patterns in the sinoatrial node Rubin R. Aliev & Roman A. Syunyaev Email: [email protected] www: http://lep.mipt.ru Moscow Institute of Physics and Technology Institute of Theoretical and Experimental Biophysics Federal Medico-Biological Agency 2 [email protected] 3 [email protected] SAN pacemaker membrane model Ach-modified currents Zhang et al. Am. J. Physiol., 279, H397-421 (2000), Zhang et al. J. Cardiovasc. Electrophysiol., 13, 465-474 (2002). Model described in: 4 [email protected] Master equation for the transmembrane current Cm i iCa ,L iCa ,T i f iK ,r iK ,s ito isus iK , ACh ib ,Na ib ,Ca ib ,K iNaK iNaCa i p ,Ca dV Na dt iNa – натриевый ток, iCa,T, iCa,L – кальциевые токи Т и L типа, if – активируемый при гиперполяризации ток, ib,Na, ib,Ca, ib,K – фоновые токи, iK,r, iK,s – быстрый и медленный калиевые токи задержанного выпрямления, ito, isus – компоненты чувствительного к 4-AP тока, iK,АCh – активируемый АЦХ калиевый ток, iNaK – Na-K насос, iNaCa – Na-Ca обменник, ip,Ca – кальциевый насос. 5 [email protected] Membrane + intracellular currents From: Алиев РР, Чайлахян ЛМ. ДАН 402 (2005). RR Aliev, LM Chailakhyan Doklady Acad Sci 402 (1), 236-239 6 [email protected] The effect of Ach on SAN cells t |ACh| = D2|ACh| - k|ACh||AChE| r ACh R AChE Алиев РР, Розенштраух ЛВ. Росс.Физиол.Ж. 92(9), 1069-1077 (2006). Aliev Rozenshtraukh Rus Physiol J. Experiment 7 [email protected] Stimulation electrode Superior vena cava Right atrium СУ 8 [email protected] Effect of vagal stimulation on SAN pacemaker cells. CL increase by 14 %. Алиев Р.Р., Абрамочкин Д., Розенштраух Л.В. Рос.Физиол.Ж., 95(1), 49-57 (2009). 9 [email protected] Phase response curves as function of stimuli number: from 1 to 10. Алиев Р.Р., Абрамочкин Д., Розенштраух Л.В. Рос.Физиол.Ж., 95(1), 49-57 (2009). 10 [email protected] Close to membrane concentrations, currents and transmembrane potential. Алиев Р.Р., Абрамочкин Д., Розенштраух Л.В. Рос.Физиол.Ж., 95(1), 49-57 (2009). 11 [email protected] PRL curves computed and experimental Алиев Р.Р., Абрамочкин Д., Розенштраух Л.В. Рос.Физиол.Ж., 95(1), 49-57 (2009). 12 [email protected] Theoretical width of the zone of positive chronotropic affect as a function of number of stimuli (а). Experiment for single stimulation (б). For phases 0.85 to 1.0 there is a positive chronotropic effect. Алиев Р.Р., Абрамочкин Д., Розенштраух Л.В. Рос.Физиол.Ж., 95(1), 49-57 (2009). 13 [email protected] Sync and De-sync od SAN cells Desynchronization Рассогласование: T с Т о r То Тс – Period of stimulation, Т0 – Period of unperturbed oscillations 14 [email protected] (а) unperturbed oscillations, Т0=340 мс; (б-д) stimulation with the period 306, 323, 374, 510 ms, which corresponds to r, -0.1, -0.05, 0.1, 0.5 (numbers left). It is seen that at positive r – increase CL; at r = –0.05 – decrease CL, at r = -0.1 – desync. Алиев Р.Р. Биофизика, т.53(6), c.1125–1128 (2008). RR Aliev Biophysics 53 (6), 645-647 15 [email protected] Established averaged ratio of frequences (а) and phase shifts (б) as functions of r. sync activity correspond to horisontal zones in (а) and monotonic parts in (б). Алиев Р.Р. Биофизика, т.53(6), c.1125–1128 (2008). RR Aliev Biophysics 53 (6), 645-647 17 [email protected] Two cells connected via gap junctions 18 [email protected] Сюняев Р.А., Алиев Р.Р. Биофизика, 54(1), 77-80 (2009). RA Siuniaev, RR Aliev Biofizika 54 (1), 77-80 19 [email protected] Сюняев Р.А., Алиев Р.Р. Биофизика, 54(1), 77-80 (2009). RA Siuniaev, RR Aliev Biofizika 54 (1), 77-80 20 [email protected] Сюняев Р.А., Алиев Р.Р. Биофизика, 54(1), 77-80 (2009). RA Siuniaev, RR Aliev Biofizika 54 (1), 77-80 21 [email protected] Development of synchronization Сюняев Р.А., Алиев Р.Р. Биофизика, 54(1), 77-80 (2009). RA Siuniaev, RR Aliev Biofizika 54 (1), 77-80 Simulating 1D, 2D, 3D 22 [email protected] Conceptual models Detail models •PDE • ODE dV C C( DE ) I ( g ,V ) dt dV C I j I ( g ,V ) dt Simulating SAN: 2D. ACh results in a functional block of conduction 23 [email protected] Syunyaev, Aliev Biophysics (rus.), 55(6), 1132 -7 (2010). 24 [email protected] Syunyaev, Aliev. RJNAMM 26(6) 575-587(2011) Simulating SAN: 2D. Inhomogeneity. Из: Dobrzynski H et al., Circulation 2005; 111:846-854. 25 [email protected] 26 Моделирование СУ: 3D. Миграция водителя ритма [email protected] 28 [email protected] Syunyaev, Aliev. RJNAMM 26(6) 575-587(2011) 29 [email protected] 2D Syunyaev, Aliev Biophysics (rus.), 55(6), 1132 -7 (2010). 3D Syunyaev, Aliev. RJNAMM 26(6) 575-587(2011) 30 [email protected] Evolution of pacemaker density in the SAN. Note the initially large number of pacemakers significantly drops during first few seconds. Syunyaev, Aliev. RJNAMM 26(6) 575-587(2011) 31 [email protected] Syunyaev, Aliev. RJNAMM 26(6) 575-587(2011) 32 [email protected] Syunyaev, Aliev. RJNAMM 26(6) 575-587(2011) 33 [email protected] 43 [email protected] Thank you for your patience! Email: [email protected] www: http://lep.mipt.ru Moscow Institute of Physics and Technology Institute of Theoretical and Experimental Biophysics Federal Medico-Biological Agency