TY - JOUR
T1 - Stretch-Activated Current Can Promote or Suppress Cardiac Alternans Depending on Voltage-Calcium Interaction
AU - Galice, Samuel
AU - Bers, Donald M
AU - Sato, Daisuke
PY - 2016/6/21
Y1 - 2016/6/21
N2 - Cardiac alternans has been linked to the onset of ventricular fibrillation and ventricular tachycardia, leading to life-threatening arrhythmias. Here, we investigated the effects of stretch-activated currents (ISAC) on alternans using a physiologically detailed model of the ventricular myocyte. We found that increasing ISAC suppresses alternans if the voltage-Ca coupling is positive or the alternans is voltage driven. However, for electromechanically discordant alternans, which occurs when the alternans is Ca driven with negative voltage-Ca coupling, increasing ISAC promotes Ca alternans. In addition, if action potential duration-Ca transients show quasiperiodicity, we observe a biphasic effect of ISAC, i.e., suppressing quasiperiodic oscillation at small stretch but promoting electromechanically discordant alternans at larger stretch. Our results demonstrate how ISAC interacts with coupled voltage-Ca dynamical systems with respect to alternans.
AB - Cardiac alternans has been linked to the onset of ventricular fibrillation and ventricular tachycardia, leading to life-threatening arrhythmias. Here, we investigated the effects of stretch-activated currents (ISAC) on alternans using a physiologically detailed model of the ventricular myocyte. We found that increasing ISAC suppresses alternans if the voltage-Ca coupling is positive or the alternans is voltage driven. However, for electromechanically discordant alternans, which occurs when the alternans is Ca driven with negative voltage-Ca coupling, increasing ISAC promotes Ca alternans. In addition, if action potential duration-Ca transients show quasiperiodicity, we observe a biphasic effect of ISAC, i.e., suppressing quasiperiodic oscillation at small stretch but promoting electromechanically discordant alternans at larger stretch. Our results demonstrate how ISAC interacts with coupled voltage-Ca dynamical systems with respect to alternans.
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U2 - 10.1016/j.bpj.2016.05.026
DO - 10.1016/j.bpj.2016.05.026
M3 - Article
C2 - 27332125
AN - SCOPUS:84975229599
VL - 110
SP - 2671
EP - 2677
JO - Biophysical Journal
JF - Biophysical Journal
SN - 0006-3495
IS - 12
ER -