Cardiac KATP channel modulation by 16Hz magnetic fields - A theoretical study

Heart exposure to 16Hz magnetic fields (MFs) was shown to be cardio-protective for diseased hearts; still, the mechanism of this effect is unknown. We hypothesize that a possible one mechanism is an increased trans-membrane KATP channel open probability due to modulation of the degree of dissociation between K+ ions, having a resonance frequency of 16Hz, and the channel selectivity filter. The Fan-Makielski Markovian KATP channel model was adopted, and the MF bio-effect was manifested by modulating the open probability of the channel using the predictive MF bio-effect parameter based on Binhi's quantum mechanics model. The model was integrated in a ventricular single cell model and the MF effect on the calcium transients [Ca2+] was assessed. Periodic pacing (Cycle Length CL=1sec) was applied and a 16Hz or 32Hz MF was turned on at t=0 for 10min. MF exposure gradually decreased [Ca2+] due to KATP channel opening, more strongly at 16Hz. Additionally, a small negative diastolic shift was observed. These numerical results demonstrated similarity to published experimental data using similar 16Hz MF exposure. We conclude that 16Hz MF exposure increases the KATP channel open probability, lowering the cellular calcium load. Our model could be integrated in a tissue model to predict optimal MF parameters for future cardiac therapy devices.