Stretch-Activated Current Can Promote or Suppress Cardiac Alternans Depending on Voltage-Calcium Interaction
- Author(s): Galice, S
- Bers, DM
- Sato, D
- et al.
Published Web Locationhttp://www.sciencedirect.com/science/article/pii/S0006349516303514
© 2016 Biophysical Society. 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 ISACsuppresses 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 ISACpromotes 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 ISACinteracts with coupled voltage-Ca dynamical systems with respect to alternans.